From 5ae153f841e69cc2c15945869cce02ba46177591 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Deniz=20=C5=9Eafak?= <denizsafak98@gmail.com>
Date: Fri, 9 Jan 2026 01:36:14 +0300
Subject: [PATCH] Reformat using black

---
 abogen/book_parser.py                         |  95 +--
 abogen/chunking.py                            |  18 +-
 abogen/debug_tts_samples.py                   |  23 +-
 abogen/entity_analysis.py                     |  70 +-
 abogen/heteronym_overrides.py                 |  12 +-
 abogen/kokoro_text_normalization.py           | 358 +++++++---
 abogen/llm_client.py                          |  18 +-
 abogen/normalization_settings.py              |  49 +-
 abogen/pronunciation_store.py                 |  67 +-
 abogen/spacy_contraction_resolver.py          |  17 +-
 abogen/spacy_utils.py                         |   6 +-
 abogen/speaker_analysis.py                    |  89 ++-
 abogen/speaker_configs.py                     |   6 +-
 abogen/subtitle_utils.py                      |   2 +
 abogen/text_extractor.py                      | 147 +++-
 abogen/tts_supertonic.py                      |  26 +-
 abogen/utils.py                               |  30 +-
 abogen/voice_cache.py                         |   4 +-
 abogen/voice_profiles.py                      |  14 +-
 build_pypi.py                                 |   3 +-
 tests/__init__.py                             |   4 +-
 tests/test_audiobookshelf_client.py           |   5 +-
 tests/test_book_handler_regression.py         |  23 +-
 tests/test_book_parser.py                     |  42 +-
 tests/test_calibre_opds.py                    | 659 +++++++++---------
 tests/test_chapter_overrides.py               |  22 +-
 tests/test_chunk_helpers.py                   |   4 +-
 tests/test_conversion_chapter_titles.py       |  13 +-
 tests/test_conversion_series.py               |   2 +-
 tests/test_conversion_voice_resolution.py     |  16 +-
 .../test_date_normalization_comprehensive.py  |  41 +-
 tests/test_debug_tts_samples.py               |  39 +-
 tests/test_epub_content_slicing.py            |  68 +-
 tests/test_epub_exporter.py                   |  46 +-
 tests/test_epub_heuristic_nav.py              |  48 +-
 tests/test_epub_html_nav_parsing.py           |  67 +-
 .../test_epub_missing_file_error_handling.py  |  30 +-
 tests/test_epub_ncx_parsing.py                |  44 +-
 tests/test_epub_standard_nav.py               |  47 +-
 tests/test_output_paths.py                    |  20 +-
 tests/test_prepare_form.py                    |  12 +-
 .../test_preview_applies_manual_overrides.py  |  10 +-
 tests/test_regression_fixes.py                |  15 +-
 tests/test_service.py                         |  16 +-
 tests/test_speaker_analysis.py                |  17 +-
 tests/test_text_extractor.py                  |  12 +-
 tests/test_text_normalization.py              |  42 +-
 tests/test_voice_cache.py                     |   6 +-
 48 files changed, 1530 insertions(+), 894 deletions(-)

diff --git a/abogen/book_parser.py b/abogen/book_parser.py
index d81d9c8..cebecc1 100644
--- a/abogen/book_parser.py
+++ b/abogen/book_parser.py
@@ -18,7 +18,9 @@ from abogen.subtitle_utils import clean_text, calculate_text_length
 _BRACKETED_NUMBERS_PATTERN = re.compile(r"\[\s*\d+\s*\]")
 _STANDALONE_PAGE_NUMBERS_PATTERN = re.compile(r"^\s*\d+\s*$", re.MULTILINE)
 _PAGE_NUMBERS_AT_END_PATTERN = re.compile(r"\s+\d+\s*$", re.MULTILINE)
-_PAGE_NUMBERS_WITH_DASH_PATTERN = re.compile(r"\s+[-–—]\s*\d+\s*[-–—]?\s*$", re.MULTILINE)
+_PAGE_NUMBERS_WITH_DASH_PATTERN = re.compile(
+    r"\s+[-–—]\s*\d+\s*[-–—]?\s*$", re.MULTILINE
+)
 
 
 class BaseBookParser(ABC):
@@ -114,7 +116,7 @@ class PdfParser(BaseBookParser):
 
         for page_num in range(len(self.pdf_doc)):
             text = clean_text(self.pdf_doc[page_num].get_text())
-            
+
             # Clean up common PDF artifacts:
             # - Remove bracketed numbers often used for citations [1]
             text = _BRACKETED_NUMBERS_PATTERN.sub("", text)
@@ -128,7 +130,7 @@ class PdfParser(BaseBookParser):
             page_id = f"page_{page_num + 1}"
             self.content_texts[page_id] = text
             self.content_lengths[page_id] = calculate_text_length(text)
-        
+
         return self.content_texts, self.content_lengths
 
     def _extract_book_metadata(self):
@@ -166,7 +168,7 @@ class MarkdownParser(BaseBookParser):
     def process_content(self, replace_single_newlines=True):
         if self.markdown_text is None:
             self.load()
-            
+
         self._process_markdown_content()
         return self.content_texts, self.content_lengths
 
@@ -255,11 +257,11 @@ class MarkdownParser(BaseBookParser):
             else:
                 self.content_texts[chapter_id] = header_name
                 self.content_lengths[chapter_id] = calculate_text_length(header_name)
-                
+
     def get_chapters(self):
         chapters = super().get_chapters()
         if not chapters and "markdown_content" in self.content_texts:
-             chapters.append(("markdown_content", "Content"))
+            chapters.append(("markdown_content", "Content"))
         return chapters
 
 
@@ -282,17 +284,19 @@ class EpubParser(BaseBookParser):
             # Patch ebooklib to skip missing files
             import types
             from ebooklib import epub as _epub_module
-            
+
             reader_class = _epub_module.EpubReader
             orig_read_file = reader_class.read_file
-            
+
             def safe_read_file(self, name):
                 try:
                     return orig_read_file(self, name)
                 except KeyError:
-                    logging.warning(f"Missing file in EPUB: {name}. Returning empty bytes.")
+                    logging.warning(
+                        f"Missing file in EPUB: {name}. Returning empty bytes."
+                    )
                     return b""
-            
+
             reader_class.read_file = safe_read_file
             try:
                 self.book = epub.read_epub(self.book_path)
@@ -302,7 +306,7 @@ class EpubParser(BaseBookParser):
     def process_content(self, replace_single_newlines=True):
         if not self.book:
             self.load()
-            
+
         self.book_metadata = self._extract_book_metadata()
         try:
             nav_item, nav_type = self._identify_nav_item()
@@ -310,7 +314,7 @@ class EpubParser(BaseBookParser):
         except Exception as e:
             logging.warning(f"EPUB nav processing failed: {e}. Falling back to spine.")
             self._process_epub_content_spine_fallback()
-            
+
         return self.content_texts, self.content_lengths
 
     def _extract_book_metadata(self):
@@ -412,7 +416,7 @@ class EpubParser(BaseBookParser):
     ):
         """
         Recursive parsing of NCX navigation nodes.
-        
+
         Logic tested by: tests/test_epub_ncx_parsing.py
         """
         nav_label = nav_point.find("navLabel")
@@ -428,7 +432,9 @@ class EpubParser(BaseBookParser):
 
         if src:
             base_href, fragment = src.split("#", 1) if "#" in src else (src, None)
-            doc_key, doc_idx = self._find_doc_key(base_href, doc_order, doc_order_decoded)
+            doc_key, doc_idx = self._find_doc_key(
+                base_href, doc_order, doc_order_decoded
+            )
             if not doc_key:
                 current_entry_node["has_content"] = False
             else:
@@ -458,19 +464,20 @@ class EpubParser(BaseBookParser):
                 )
 
         if title and (
-            current_entry_node.get("has_content", False) or current_entry_node["children"]
+            current_entry_node.get("has_content", False)
+            or current_entry_node["children"]
         ):
             tree_structure_list.append(current_entry_node)
 
     def _extract_nav_li_title(self, li_element, link_element=None, span_element=None):
         """Helper to extract title from a nav <li> element, handling various structures."""
         title = "Untitled Section"
-        
+
         if link_element:
             title = link_element.get_text(strip=True) or title
         elif span_element:
             title = span_element.get_text(strip=True) or title
-            
+
         # Fallback to direct text if title is empty or default
         # If we used link/span but got empty string, we try fallback.
         # If we didn't use link/span, we try fallback.
@@ -480,11 +487,11 @@ class EpubParser(BaseBookParser):
             ).strip()
             if li_text:
                 title = li_text
-                
-        # Second fallback: if we have a span but title is still empty, try span text again 
+
+        # Second fallback: if we have a span but title is still empty, try span text again
         # (covered by logic above mostly, but mirroring original logic's intense fallback)
         if (not title.strip() or title == "Untitled Section") and span_text:
-             title = span_text.get_text(strip=True) or title
+            title = span_text.get_text(strip=True) or title
 
         return title
 
@@ -499,7 +506,7 @@ class EpubParser(BaseBookParser):
     ):
         """
         Recursive parsing of HTML5 Navigation (li) nodes.
-        
+
         Logic tested by: tests/test_epub_html_nav_parsing.py
         """
         link = li_element.find("a", recursive=False)
@@ -509,7 +516,7 @@ class EpubParser(BaseBookParser):
 
         if link and "href" in link.attrs:
             src = link["href"]
-            
+
         title = self._extract_nav_li_title(li_element, link, span_text)
 
         current_entry_node["title"] = title
@@ -521,7 +528,9 @@ class EpubParser(BaseBookParser):
         fragment = None
         if src:
             base_href, fragment = src.split("#", 1) if "#" in src else (src, None)
-            doc_key, doc_idx = self._find_doc_key(base_href, doc_order, doc_order_decoded)
+            doc_key, doc_idx = self._find_doc_key(
+                base_href, doc_order, doc_order_decoded
+            )
             if doc_key is not None:
                 position = find_position_func(doc_key, fragment)
                 entry_data = {
@@ -557,18 +566,21 @@ class EpubParser(BaseBookParser):
 
         # 1. Check ITEM_NAVIGATION
         nav_items = list(self.book.get_items_of_type(ebooklib.ITEM_NAVIGATION))
-        
+
         # 1.1 Support for EPUB 3 EpubNav which might be ITEM_DOCUMENT (9) but with properties=['nav']
         if not nav_items:
-             # Look in ITEM_DOCUMENT for items with 'nav' property
-             for item in self.book.get_items_of_type(ebooklib.ITEM_DOCUMENT):
-                 if hasattr(item, 'get_type') and item.get_type() == ebooklib.ITEM_DOCUMENT:
-                     # Check properties - ebooklib stores opf properties in list
-                     # Some versions use item.properties, some need checking
-                     props = getattr(item, 'properties', [])
-                     if 'nav' in props:
-                         nav_items.append(item)
-        
+            # Look in ITEM_DOCUMENT for items with 'nav' property
+            for item in self.book.get_items_of_type(ebooklib.ITEM_DOCUMENT):
+                if (
+                    hasattr(item, "get_type")
+                    and item.get_type() == ebooklib.ITEM_DOCUMENT
+                ):
+                    # Check properties - ebooklib stores opf properties in list
+                    # Some versions use item.properties, some need checking
+                    props = getattr(item, "properties", [])
+                    if "nav" in props:
+                        nav_items.append(item)
+
         if nav_items:
             nav_item = next(
                 (
@@ -592,7 +604,11 @@ class EpubParser(BaseBookParser):
         # 2. NCX in NAV
         if not nav_item and nav_items:
             ncx_in_nav = next(
-                (item for item in nav_items if item.get_name().lower().endswith(".ncx")),
+                (
+                    item
+                    for item in nav_items
+                    if item.get_name().lower().endswith(".ncx")
+                ),
                 None,
             )
             if ncx_in_nav:
@@ -624,9 +640,8 @@ class EpubParser(BaseBookParser):
 
         if not nav_item or not nav_type:
             raise ValueError("No navigation document found")
-            
-        return nav_item, nav_type
 
+        return nav_item, nav_type
 
     def _execute_nav_parsing_logic(self, nav_item, nav_type):
         """Parse the identified navigation item and slice content accordingly."""
@@ -826,10 +841,10 @@ class EpubParser(BaseBookParser):
                             "has_content": True,
                         },
                     )
-    
+
     def _process_epub_content_spine_fallback(self):
         """
-        Process EPUB content using the spine (linear reading order) 
+        Process EPUB content using the spine (linear reading order)
         when navigation processing fails.
         """
         logging.info("Using spine fallback for EPUB processing.")
@@ -877,7 +892,7 @@ class EpubParser(BaseBookParser):
                 if text:
                     self.content_texts[doc_href] = text
                     self.content_lengths[doc_href] = calculate_text_length(text)
-    
+
     def get_chapters(self):
         chapters = super().get_chapters()
         if not chapters:
@@ -898,7 +913,7 @@ def get_book_parser(book_path, file_type=None):
     Factory function to get the appropriate parser instance.
     """
     book_path = os.path.normpath(os.path.abspath(book_path))
-    
+
     if not file_type:
         if book_path.lower().endswith(".pdf"):
             file_type = "pdf"
diff --git a/abogen/chunking.py b/abogen/chunking.py
index db914ed..2d6f03b 100644
--- a/abogen/chunking.py
+++ b/abogen/chunking.py
@@ -80,7 +80,9 @@ def _normalize_whitespace(value: str) -> str:
 
 def _normalize_chunk_text(value: str) -> str:
     settings = get_runtime_settings()
-    config = build_apostrophe_config(settings=settings, base=_PIPELINE_APOSTROPHE_CONFIG)
+    config = build_apostrophe_config(
+        settings=settings, base=_PIPELINE_APOSTROPHE_CONFIG
+    )
     normalized = normalize_for_pipeline(value, config=config, settings=settings)
     return _normalize_whitespace(normalized)
 
@@ -158,12 +160,16 @@ def chunk_text(
 
     # Sentence level – flatten paragraphs into individual sentences
     sentence_index = 0
-    for para_index, paragraph in enumerate(list(_iter_paragraphs(text)) or [text.strip()]):
+    for para_index, paragraph in enumerate(
+        list(_iter_paragraphs(text)) or [text.strip()]
+    ):
         normalized_para = _normalize_whitespace(paragraph)
         if not normalized_para:
             continue
         sentence_pairs = _split_sentences(paragraph) or [(normalized_para, paragraph)]
-        for sent_local_index, (normalized_sentence, raw_sentence) in enumerate(sentence_pairs):
+        for sent_local_index, (normalized_sentence, raw_sentence) in enumerate(
+            sentence_pairs
+        ):
             normalized_sentence = _normalize_whitespace(normalized_sentence)
             if not normalized_sentence:
                 continue
@@ -203,7 +209,9 @@ def _build_display_pattern(text: str) -> Pattern[str]:
     return pattern
 
 
-def _search_source_span(source: str, normalized: str, start: int) -> Optional[Tuple[int, int]]:
+def _search_source_span(
+    source: str, normalized: str, start: int
+) -> Optional[Tuple[int, int]]:
     if not normalized:
         return None
     pattern = _build_display_pattern(normalized)
@@ -264,4 +272,4 @@ def build_chunks_for_chapters(
             chunk_prefix=str(prefix),
         )
         all_chunks.extend(chapter_chunks)
-    return all_chunks
\ No newline at end of file
+    return all_chunks
diff --git a/abogen/debug_tts_samples.py b/abogen/debug_tts_samples.py
index 6fa4c52..f881101 100644
--- a/abogen/debug_tts_samples.py
+++ b/abogen/debug_tts_samples.py
@@ -287,12 +287,12 @@ def build_debug_epub(dest_path: Path, *, title: str = "abogen debug samples") ->
     dest_path.parent.mkdir(parents=True, exist_ok=True)
 
     chapter_lines: List[str] = [
-        "<?xml version=\"1.0\" encoding=\"utf-8\"?>",
+        '<?xml version="1.0" encoding="utf-8"?>',
         "<!DOCTYPE html>",
-        "<html xmlns=\"http://www.w3.org/1999/xhtml\">",
+        '<html xmlns="http://www.w3.org/1999/xhtml">',
         "<head>",
         f"  <title>{title}</title>",
-        "  <meta charset=\"utf-8\" />",
+        '  <meta charset="utf-8" />',
         "</head>",
         "<body>",
         f"  <h1>{title}</h1>",
@@ -303,7 +303,11 @@ def build_debug_epub(dest_path: Path, *, title: str = "abogen debug samples") ->
         safe_label = sample.label.replace("&", "and")
         chapter_lines.append(f"  <h2>{safe_label}</h2>")
         chapter_lines.append(
-            "  <p><strong>" + marker_for(sample.code) + "</strong> " + sample.text + "</p>"
+            "  <p><strong>"
+            + marker_for(sample.code)
+            + "</strong> "
+            + sample.text
+            + "</p>"
         )
 
     chapter_lines += ["</body>", "</html>"]
@@ -366,8 +370,15 @@ def build_debug_epub(dest_path: Path, *, title: str = "abogen debug samples") ->
 
         # Per EPUB spec: mimetype must be the first entry and stored (no compression).
         with zipfile.ZipFile(dest_path, "w") as zf:
-            zf.write(tmp_path / "mimetype", "mimetype", compress_type=zipfile.ZIP_STORED)
-            for source in (meta_inf / "container.xml", oebps / "content.opf", oebps / "chapter.xhtml", oebps / "nav.xhtml"):
+            zf.write(
+                tmp_path / "mimetype", "mimetype", compress_type=zipfile.ZIP_STORED
+            )
+            for source in (
+                meta_inf / "container.xml",
+                oebps / "content.opf",
+                oebps / "chapter.xhtml",
+                oebps / "nav.xhtml",
+            ):
                 arcname = str(source.relative_to(tmp_path)).replace("\\", "/")
                 zf.write(source, arcname, compress_type=zipfile.ZIP_DEFLATED)
 
diff --git a/abogen/entity_analysis.py b/abogen/entity_analysis.py
index 34ef2d2..4c0b561 100644
--- a/abogen/entity_analysis.py
+++ b/abogen/entity_analysis.py
@@ -82,7 +82,10 @@ _EXCLUDED_NER_LABELS = {
     "QUANTITY",
 }
 
-_TITLE_PATTERN = re.compile(r"^(?:" + "|".join(re.escape(prefix) for prefix in _TITLE_PREFIXES) + r")\.?\s+", re.IGNORECASE)
+_TITLE_PATTERN = re.compile(
+    r"^(?:" + "|".join(re.escape(prefix) for prefix in _TITLE_PREFIXES) + r")\.?\s+",
+    re.IGNORECASE,
+)
 _POSSESSIVE_PATTERN = re.compile(r"(?:'s|’s|\u2019s)$", re.IGNORECASE)
 _NON_WORD_PATTERN = re.compile(r"[^\w\s'-]+")
 _MULTI_SPACE_PATTERN = re.compile(r"\s+")
@@ -104,7 +107,9 @@ class EntityRecord:
     forms: Counter = field(default_factory=Counter)
     first_position: Optional[Tuple[int, int]] = None
 
-    def register(self, *, chapter_index: int, position: int, text: str, sentence: Optional[str]) -> None:
+    def register(
+        self, *, chapter_index: int, position: int, text: str, sentence: Optional[str]
+    ) -> None:
         self.count += 1
         self.chapter_indices.add(chapter_index)
         self.forms[text] += 1
@@ -163,7 +168,9 @@ def _resolve_model_name(language: str) -> str:
 
 def _load_model(language: str) -> Any:
     if spacy is None:
-        raise EntityModelError("spaCy is not available. Install spaCy to enable entity extraction.")
+        raise EntityModelError(
+            "spaCy is not available. Install spaCy to enable entity extraction."
+        )
 
     model_name = _resolve_model_name(language)
     cache_key = model_name.lower()
@@ -249,7 +256,9 @@ def _extract_propn_tokens(doc: Any) -> Iterable[Any]:  # type: ignore[override]
         yield doc[token.i : token.i + 1]
 
 
-def _empty_result(cache_key: str, error: Optional[str] = None) -> EntityExtractionResult:
+def _empty_result(
+    cache_key: str, error: Optional[str] = None
+) -> EntityExtractionResult:
     payload = {
         "people": [],
         "entities": [],
@@ -262,7 +271,9 @@ def _empty_result(cache_key: str, error: Optional[str] = None) -> EntityExtracti
         "model": None,
     }
     errors = [error] if error else []
-    return EntityExtractionResult(summary=payload, cache_key=cache_key, elapsed=0.0, errors=errors)
+    return EntityExtractionResult(
+        summary=payload, cache_key=cache_key, elapsed=0.0, errors=errors
+    )
 
 
 def extract_entities(
@@ -319,18 +330,25 @@ def extract_entities(
             key = _token_key(cleaned)
             if not key:
                 return
-            category = category_hint or ("people" if span.label_ == "PERSON" else "entities")
+            category = category_hint or (
+                "people" if span.label_ == "PERSON" else "entities"
+            )
             record_key = (category, key)
             record = records.get(record_key)
             if record is None:
                 record = EntityRecord(
                     key=record_key,
                     label=cleaned,
-                    kind=span.label_ or ("PROPN" if category == "entities" else "PERSON"),
+                    kind=span.label_
+                    or ("PROPN" if category == "entities" else "PERSON"),
                     category=category,
                 )
                 records[record_key] = record
-            sentence = span.sent.text if hasattr(span, "sent") and span.sent is not None else None
+            sentence = (
+                span.sent.text
+                if hasattr(span, "sent") and span.sent is not None
+                else None
+            )
             record.register(
                 chapter_index=chapter_index,
                 position=span.start,
@@ -361,7 +379,9 @@ def extract_entities(
 
     elapsed = time.perf_counter() - start
 
-    people_records = [record for record in records.values() if record.category == "people"]
+    people_records = [
+        record for record in records.values() if record.category == "people"
+    ]
     people_keys = {record.key[1] for record in people_records}
     entity_records = [
         record
@@ -374,10 +394,16 @@ def extract_entities(
     people_records.sort(key=lambda rec: (-rec.count, rec.label))
     entity_records.sort(key=lambda rec: (-rec.count, rec.label))
 
-    people_payload = [record.as_dict(index + 1) for index, record in enumerate(people_records)]
-    entity_payload = [record.as_dict(index + 1) for index, record in enumerate(entity_records)]
+    people_payload = [
+        record.as_dict(index + 1) for index, record in enumerate(people_records)
+    ]
+    entity_payload = [
+        record.as_dict(index + 1) for index, record in enumerate(entity_records)
+    ]
 
-    index_payload = sorted(tokens_for_index.values(), key=lambda item: (-item["count"], item["token"]))
+    index_payload = sorted(
+        tokens_for_index.values(), key=lambda item: (-item["count"], item["token"])
+    )
 
     summary = {
         "people": people_payload,
@@ -397,10 +423,14 @@ def extract_entities(
         },
     }
 
-    return EntityExtractionResult(summary=summary, cache_key=cache_key, elapsed=elapsed, errors=[])
+    return EntityExtractionResult(
+        summary=summary, cache_key=cache_key, elapsed=elapsed, errors=[]
+    )
 
 
-def search_tokens(index: Mapping[str, Any], query: str, *, limit: int = 15) -> List[Dict[str, Any]]:
+def search_tokens(
+    index: Mapping[str, Any], query: str, *, limit: int = 15
+) -> List[Dict[str, Any]]:
     tokens = index.get("tokens") if isinstance(index, Mapping) else None
     if not isinstance(tokens, list) or not query:
         return []
@@ -411,14 +441,18 @@ def search_tokens(index: Mapping[str, Any], query: str, *, limit: int = 15) -> L
     for entry in tokens:
         token_label = str(entry.get("token", ""))
         normalized_label = token_label.lower()
-        if normalized in normalized_label or normalized in str(entry.get("normalized", "")):
+        if normalized in normalized_label or normalized in str(
+            entry.get("normalized", "")
+        ):
             results.append(entry)
         if len(results) >= limit:
             break
     return results
 
 
-def merge_override(summary: Mapping[str, Any], overrides: Mapping[str, Mapping[str, Any]]) -> Dict[str, Any]:
+def merge_override(
+    summary: Mapping[str, Any], overrides: Mapping[str, Mapping[str, Any]]
+) -> Dict[str, Any]:
     if not isinstance(summary, Mapping):
         return {"people": [], "entities": []}
     merged_summary: Dict[str, Any] = dict(summary)
@@ -430,7 +464,9 @@ def merge_override(summary: Mapping[str, Any], overrides: Mapping[str, Mapping[s
         for entry in items:
             if not isinstance(entry, Mapping):
                 continue
-            normalized = _token_key(str(entry.get("normalized") or entry.get("label") or ""))
+            normalized = _token_key(
+                str(entry.get("normalized") or entry.get("label") or "")
+            )
             merged = dict(entry)
             if normalized and normalized in overrides:
                 merged_override = dict(overrides[normalized])
diff --git a/abogen/heteronym_overrides.py b/abogen/heteronym_overrides.py
index dbb5384..08cbd07 100644
--- a/abogen/heteronym_overrides.py
+++ b/abogen/heteronym_overrides.py
@@ -152,7 +152,9 @@ def _word_boundary_pattern(token: str) -> re.Pattern[str]:
     if cached is not None:
         return cached
     escaped = re.escape(token)
-    pattern = re.compile(rf"(?i)(?<!\w){escaped}(?P<possessive>'s|\u2019s|\u2019)?(?!\w)")
+    pattern = re.compile(
+        rf"(?i)(?<!\w){escaped}(?P<possessive>'s|\u2019s|\u2019)?(?!\w)"
+    )
     _WORD_BOUNDARY_CACHE[key] = pattern
     return pattern
 
@@ -167,7 +169,9 @@ def _preserve_case(replacement: str, original: str) -> str:
     return replacement
 
 
-def _build_replacement_sentence(sentence: str, token: str, replacement_token: str) -> str:
+def _build_replacement_sentence(
+    sentence: str, token: str, replacement_token: str
+) -> str:
     pattern = _word_boundary_pattern(token)
 
     def _repl(match: re.Match[str]) -> str:
@@ -271,7 +275,9 @@ def extract_heteronym_overrides(
                 options: List[Dict[str, Any]] = []
                 for variant in spec.variants:
                     replacement_sentence = _build_replacement_sentence(
-                        sentence, token=spec.token, replacement_token=variant.replacement_token
+                        sentence,
+                        token=spec.token,
+                        replacement_token=variant.replacement_token,
                     )
                     options.append(
                         {
diff --git a/abogen/kokoro_text_normalization.py b/abogen/kokoro_text_normalization.py
index 563e63d..17665ad 100644
--- a/abogen/kokoro_text_normalization.py
+++ b/abogen/kokoro_text_normalization.py
@@ -7,7 +7,18 @@ import os
 import locale
 from fractions import Fraction
 from dataclasses import dataclass, field
-from typing import TYPE_CHECKING, Any, Callable, Dict, Iterable, List, Mapping, Optional, Sequence, Tuple
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Callable,
+    Dict,
+    Iterable,
+    List,
+    Mapping,
+    Optional,
+    Sequence,
+    Tuple,
+)
 import logging
 
 logger = logging.getLogger(__name__)
@@ -16,7 +27,9 @@ try:  # pragma: no cover - optional dependency guard
     from num2words import num2words
 except ImportError:
     num2words = None
-    logger.warning("num2words library not found. Number normalization will be disabled.")
+    logger.warning(
+        "num2words library not found. Number normalization will be disabled."
+    )
 except Exception as e:  # pragma: no cover - graceful degradation
     num2words = None
     logger.error(f"Failed to import num2words: {e}")
@@ -41,34 +54,44 @@ CONTRACTION_CATEGORY_DEFAULTS: Dict[str, bool] = {
 
 # ---------- Configuration Dataclass ----------
 
+
 @dataclass
 class ApostropheConfig:
-    contraction_mode: str = "expand"              # expand|collapse|keep
-    possessive_mode: str = "keep"                 # keep|collapse
-    plural_possessive_mode: str = "collapse"      # keep|collapse
-    irregular_possessive_mode: str = "keep"       # keep|expand (expand just means keep or add hints; modify if needed)
-    sibilant_possessive_mode: str = "mark"        # keep|mark|approx
-    fantasy_mode: str = "keep"                    # keep|mark|collapse_internal
-    acronym_possessive_mode: str = "keep"         # keep|collapse_add_s
-    decades_mode: str = "expand"                  # keep|expand
-    leading_elision_mode: str = "expand"          # keep|expand
-    ambiguous_past_modal_mode: str = "contextual" # keep|expand_prefer_would|expand_prefer_had|contextual
-    add_phoneme_hints: bool = True                # Whether to emit markers like ‹IZ›
-    fantasy_marker: str = "‹FAP›"                 # Marker inserted if fantasy_mode == mark
-    sibilant_iz_marker: str = "‹IZ›"              # Marker for /ɪz/ insertion
-    joiner: str = ""                              # Replacement used when collapsing internal apostrophes
-    lowercase_for_matching: bool = True           # Normalize to lower for rule matching (not output)
-    protect_cultural_names: bool = True           # Always keep O'Brien, D'Angelo, etc.
-    convert_numbers: bool = True                  # Convert grouped numbers such as 12,500 to words
-    convert_currency: bool = True                 # Convert currency symbols to words
-    remove_footnotes: bool = True                 # Remove footnote indicators
-    number_lang: str = "en"                       # num2words language code
-    year_pronunciation_mode: str = "american"     # off|american (extend if needed)
-    contraction_categories: Dict[str, bool] = field(default_factory=lambda: dict(CONTRACTION_CATEGORY_DEFAULTS))
+    contraction_mode: str = "expand"  # expand|collapse|keep
+    possessive_mode: str = "keep"  # keep|collapse
+    plural_possessive_mode: str = "collapse"  # keep|collapse
+    irregular_possessive_mode: str = (
+        "keep"  # keep|expand (expand just means keep or add hints; modify if needed)
+    )
+    sibilant_possessive_mode: str = "mark"  # keep|mark|approx
+    fantasy_mode: str = "keep"  # keep|mark|collapse_internal
+    acronym_possessive_mode: str = "keep"  # keep|collapse_add_s
+    decades_mode: str = "expand"  # keep|expand
+    leading_elision_mode: str = "expand"  # keep|expand
+    ambiguous_past_modal_mode: str = (
+        "contextual"  # keep|expand_prefer_would|expand_prefer_had|contextual
+    )
+    add_phoneme_hints: bool = True  # Whether to emit markers like ‹IZ›
+    fantasy_marker: str = "‹FAP›"  # Marker inserted if fantasy_mode == mark
+    sibilant_iz_marker: str = "‹IZ›"  # Marker for /ɪz/ insertion
+    joiner: str = ""  # Replacement used when collapsing internal apostrophes
+    lowercase_for_matching: bool = (
+        True  # Normalize to lower for rule matching (not output)
+    )
+    protect_cultural_names: bool = True  # Always keep O'Brien, D'Angelo, etc.
+    convert_numbers: bool = True  # Convert grouped numbers such as 12,500 to words
+    convert_currency: bool = True  # Convert currency symbols to words
+    remove_footnotes: bool = True  # Remove footnote indicators
+    number_lang: str = "en"  # num2words language code
+    year_pronunciation_mode: str = "american"  # off|american (extend if needed)
+    contraction_categories: Dict[str, bool] = field(
+        default_factory=lambda: dict(CONTRACTION_CATEGORY_DEFAULTS)
+    )
 
     def is_contraction_enabled(self, category: str) -> bool:
         return self.contraction_categories.get(category, True)
 
+
 # ---------- Dictionaries / Patterns ----------
 
 # Common contraction expansions (type + expansion words)
@@ -124,14 +147,18 @@ _FRACTION_RE = re.compile(
 
 _CURRENCY_RE = re.compile(
     r"(?P<symbol>[$£€¥])\s*(?P<amount>\d{1,3}(?:,\d{3})*(?:\.\d+)?)(?:\s+(?P<magnitude>hundred|thousand|million|billion|trillion|quadrillion))?(?!\d)",
-    re.IGNORECASE
+    re.IGNORECASE,
 )
 
-_URL_RE = re.compile(r"(https?://)?(www\.)?(?P<domain>[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)+)(/[^\s]*)?")
+_URL_RE = re.compile(
+    r"(https?://)?(www\.)?(?P<domain>[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)+)(/[^\s]*)?"
+)
 _FOOTNOTE_RE = re.compile(r"([a-zA-Z]+)(\d+)")
 _BRACKET_FOOTNOTE_RE = re.compile(r"\[\d+\]")
 
-_ISO_DATE_RE = re.compile(r"\b(?P<year>\d{4})[/-](?P<month>\d{1,2})[/-](?P<day>\d{1,2})\b")
+_ISO_DATE_RE = re.compile(
+    r"\b(?P<year>\d{4})[/-](?P<month>\d{1,2})[/-](?P<day>\d{1,2})\b"
+)
 _MDY_DATE_RE = re.compile(
     r"\b(?P<month>Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)?|May|Jun(?:e)?|Jul(?:y)?|Aug(?:ust)?|Sep(?:t(?:ember)?)?|Oct(?:ober)?|Nov(?:ember)?|Dec(?:ember)?)\.?\s+"
     r"(?P<day>\d{1,2})(?:st|nd|rd|th)?\s*,\s*(?P<year>\d{4})\b",
@@ -143,7 +170,9 @@ _TIME_RE = re.compile(
     re.IGNORECASE,
 )
 
-_ADDRESS_ABBR_RE = re.compile(r"(?P<prefix>\b\w+\s+)(?P<abbr>St|Rd|Ave|Blvd|Ln|Dr)\.(?=\s*(?:,|\.|!|\?|$))")
+_ADDRESS_ABBR_RE = re.compile(
+    r"(?P<prefix>\b\w+\s+)(?P<abbr>St|Rd|Ave|Blvd|Ln|Dr)\.(?=\s*(?:,|\.|!|\?|$))"
+)
 
 _MONTH_MAP = {
     "jan": "January",
@@ -218,25 +247,27 @@ def _normalize_dates(text: str, language: str) -> str:
         day = int(match.group("day"))
         if not (1 <= month <= 12 and 1 <= day <= 31):
             return match.group(0)
-        month_name = (
-            [
-                "January",
-                "February",
-                "March",
-                "April",
-                "May",
-                "June",
-                "July",
-                "August",
-                "September",
-                "October",
-                "November",
-                "December",
-            ][month - 1]
-        )
+        month_name = [
+            "January",
+            "February",
+            "March",
+            "April",
+            "May",
+            "June",
+            "July",
+            "August",
+            "September",
+            "October",
+            "November",
+            "December",
+        ][month - 1]
         ordinal = _int_to_ordinal_words(day, language) or str(day)
         year_words = _year_to_words_american(year, language)
-        return f"{month_name} {ordinal}, {year_words}" if us else f"{ordinal} {month_name} {year_words}"
+        return (
+            f"{month_name} {ordinal}, {year_words}"
+            if us
+            else f"{ordinal} {month_name} {year_words}"
+        )
 
     def _format_mdy(match: re.Match[str]) -> str:
         month_raw = str(match.group("month") or "").strip().lower().rstrip(".")
@@ -247,7 +278,11 @@ def _normalize_dates(text: str, language: str) -> str:
         year = int(match.group("year"))
         ordinal = _int_to_ordinal_words(day, language) or str(day)
         year_words = _year_to_words_american(year, language)
-        return f"{month_name} {ordinal}, {year_words}" if us else f"{ordinal} {month_name} {year_words}"
+        return (
+            f"{month_name} {ordinal}, {year_words}"
+            if us
+            else f"{ordinal} {month_name} {year_words}"
+        )
 
     out = _ISO_DATE_RE.sub(_format_iso, text)
     out = _MDY_DATE_RE.sub(_format_mdy, out)
@@ -301,6 +336,7 @@ def _normalize_internet_slang(text: str) -> str:
 
     return re.sub(r"\b(?:pls|plz)\b", _replace, text, flags=re.IGNORECASE)
 
+
 _DECIMAL_NUMBER_RE = re.compile(
     rf"(?<![\w{_NUMBER_RANGE_CLASS}/])(?P<number>-?(?:\d{{1,3}}(?:,\d{{3}})+|\d+)\.(?P<fraction>\d+))(?![\w{_NUMBER_RANGE_CLASS}/])"
 )
@@ -308,7 +344,18 @@ _PLAIN_NUMBER_RE = re.compile(
     rf"(?<![\w{_NUMBER_RANGE_CLASS}/])(?P<number>{_NUMBER_CORE_PATTERN})(?![\w{_NUMBER_RANGE_CLASS}/])"
 )
 
-_DIGIT_WORDS = ("zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine")
+_DIGIT_WORDS = (
+    "zero",
+    "one",
+    "two",
+    "three",
+    "four",
+    "five",
+    "six",
+    "seven",
+    "eight",
+    "nine",
+)
 
 
 def _int_to_words(value: int, language: str) -> Optional[str]:
@@ -384,7 +431,9 @@ def _pluralize_fraction_word(base: str) -> str:
     return base + "s"
 
 
-def _fraction_denominator_word(denominator: int, numerator: int, language: str) -> Optional[str]:
+def _fraction_denominator_word(
+    denominator: int, numerator: int, language: str
+) -> Optional[str]:
     """Return spoken form for fraction denominator respecting plurality."""
     if denominator == 0:
         return None
@@ -405,7 +454,9 @@ def _fraction_denominator_word(denominator: int, numerator: int, language: str)
     return _pluralize_fraction_word(base)
 
 
-def _format_fraction_words(numerator: int, denominator: int, language: str) -> Optional[str]:
+def _format_fraction_words(
+    numerator: int, denominator: int, language: str
+) -> Optional[str]:
     """Return spoken representation of a simple fraction."""
     if denominator == 0:
         return None
@@ -492,7 +543,9 @@ def _coerce_int_token(token: str) -> Optional[int]:
         return int(cleaned)
     except ValueError:
         return None
-AMBIGUOUS_D_BASES = {"i","you","he","she","we","they"}
+
+
+AMBIGUOUS_D_BASES = {"i", "you", "he", "she", "we", "they"}
 AMBIGUOUS_S_BASES = {
     "it",
     "that",
@@ -520,6 +573,7 @@ def _is_ambiguous_s(token: str) -> bool:
     low = token.lower()
     return low.endswith("'s") and low[:-2] in AMBIGUOUS_S_BASES
 
+
 # Irregular possessives that are not formed by simple + 's logic
 IRREGULAR_POSSESSIVES = {
     "children's": "children's",
@@ -527,12 +581,12 @@ IRREGULAR_POSSESSIVES = {
     "women's": "women's",
     "people's": "people's",
     "geese's": "geese's",
-    "mouse's": "mouse's",   # singular irregular
+    "mouse's": "mouse's",  # singular irregular
 }
 
 SIBILANT_END_RE = re.compile(r"(?:[sxz]|(?:ch|sh))$", re.IGNORECASE)
 
-DECADE_RE = re.compile(r"^'\d0s$", re.IGNORECASE)          # '90s, '80s
+DECADE_RE = re.compile(r"^'\d0s$", re.IGNORECASE)  # '90s, '80s
 LEADING_ELISION = {
     "'tis": "it is",
     "'twas": "it was",
@@ -546,7 +600,7 @@ CULTURAL_NAME_PATTERNS = [
     re.compile(r"^O'[A-Z][a-z]+$"),
     re.compile(r"^D'[A-Z][a-z]+$"),
     re.compile(r"^L'[A-Za-z].*$"),
-    re.compile(r"^Mc[A-Z].*$"),   # not apostrophe, but often relevant (kept anyway)
+    re.compile(r"^Mc[A-Z].*$"),  # not apostrophe, but often relevant (kept anyway)
 ]
 
 ACRONYM_POSSESSIVE_RE = re.compile(r"^[A-Z]{2,}'s$")
@@ -563,7 +617,7 @@ WORD_TOKEN_RE = re.compile(
 APOSTROPHE_CHARS = "’`´ꞌʼ"
 
 TERMINAL_PUNCTUATION = {".", "?", "!", "…", ";", ":"}
-CLOSING_PUNCTUATION = '"\'”’)]}»›'
+CLOSING_PUNCTUATION = "\"'”’)]}»›"
 ELLIPSIS_SUFFIXES = ("...", "…")
 _LINE_SPLIT_RE = re.compile(r"(\n+)")
 
@@ -584,29 +638,38 @@ SUFFIX_ABBREVIATIONS = {
 }
 
 _TITLE_PATTERN = re.compile(
-    r"\b(?P<abbr>" + "|".join(sorted(TITLE_ABBREVIATIONS.keys(), key=len, reverse=True)) + r")\.",
+    r"\b(?P<abbr>"
+    + "|".join(sorted(TITLE_ABBREVIATIONS.keys(), key=len, reverse=True))
+    + r")\.",
     re.IGNORECASE,
 )
 _SUFFIX_PATTERN = re.compile(
-    r"\b(?P<abbr>" + "|".join(sorted(SUFFIX_ABBREVIATIONS.keys(), key=len, reverse=True)) + r")\.",
+    r"\b(?P<abbr>"
+    + "|".join(sorted(SUFFIX_ABBREVIATIONS.keys(), key=len, reverse=True))
+    + r")\.",
     re.IGNORECASE,
 )
 
 # ---------- Utility Functions ----------
 
+
 def normalize_unicode_apostrophes(text: str) -> str:
     text = unicodedata.normalize("NFKC", text)
     for ch in APOSTROPHE_CHARS:
         text = text.replace(ch, "'")
     return text
 
+
 def tokenize(text: str) -> List[str]:
     # Simple tokenization preserving punctuation tokens
     return WORD_TOKEN_RE.findall(text)
 
 
 def tokenize_with_spans(text: str) -> List[Tuple[str, int, int]]:
-    return [(match.group(0), match.start(), match.end()) for match in WORD_TOKEN_RE.finditer(text)]
+    return [
+        (match.group(0), match.start(), match.end())
+        for match in WORD_TOKEN_RE.finditer(text)
+    ]
 
 
 def _cleanup_spacing(text: str) -> str:
@@ -661,7 +724,9 @@ _ROMAN_COMPOSE_ORDER = [
     (1, "I"),
 ]
 
-_ROMAN_PREFIX_RE = re.compile(r"^(?P<roman>[IVXLCDM]+)(?P<sep>[\s\.:,;\-–—]*)", re.IGNORECASE)
+_ROMAN_PREFIX_RE = re.compile(
+    r"^(?P<roman>[IVXLCDM]+)(?P<sep>[\s\.:,;\-–—]*)", re.IGNORECASE
+)
 
 _ROMAN_TOKEN_RE = re.compile(r"^[IVXLCDM]+$")
 _ROMAN_CARDINAL_CONTEXTS = {
@@ -816,7 +881,9 @@ def _token_is_cardinal_context(token: str) -> bool:
     return token.lower() in _ROMAN_CARDINAL_CONTEXTS
 
 
-def _has_cardinal_leading_context(tokens: Sequence[Tuple[str, int, int]], index: int) -> bool:
+def _has_cardinal_leading_context(
+    tokens: Sequence[Tuple[str, int, int]], index: int
+) -> bool:
     j = index - 1
     while j >= 0:
         token, *_ = tokens[j]
@@ -927,7 +994,9 @@ def _normalize_roman_numerals(text: str, language: str) -> str:
                     if len(token) >= 2:
                         if token.isupper():
                             convert = True
-                        elif numeric_value <= 200 and _has_cardinal_leading_context(tokens, index):
+                        elif numeric_value <= 200 and _has_cardinal_leading_context(
+                            tokens, index
+                        ):
                             convert = True
                     elif len(token) == 1:
                         # Only convert single letters if context is strong
@@ -1002,7 +1071,10 @@ def _should_preserve_caps_word(word: str) -> bool:
     upper_base = base.upper()
     if upper_base in _ACRONYM_ALLOWLIST:
         return True
-    if all(ch in _ROMAN_NUMERAL_LETTERS for ch in letters.upper()) and len(letters) <= 7:
+    if (
+        all(ch in _ROMAN_NUMERAL_LETTERS for ch in letters.upper())
+        and len(letters) <= 7
+    ):
         return True
     return False
 
@@ -1128,7 +1200,7 @@ def normalize_roman_numeral_titles(
 
         roman_token = match.group("roman")
         separator = match.group("sep") or ""
-        rest = stripped[match.end():]
+        rest = stripped[match.end() :]
 
         if not separator and rest and rest[:1].isalnum():
             normalized.append(title)
@@ -1269,7 +1341,9 @@ def _apply_contraction_policy(
     return expand()
 
 
-def _assemble_contraction_expansion(base_text: str, surface_text: str, expansion_word: str) -> str:
+def _assemble_contraction_expansion(
+    base_text: str, surface_text: str, expansion_word: str
+) -> str:
     if not expansion_word:
         return base_text
 
@@ -1340,6 +1414,7 @@ def _classify_ambiguous_s(token: str, cfg: ApostropheConfig) -> Tuple[str, str]:
 
     return candidates[0][0], token
 
+
 def classify_token(token: str, cfg: ApostropheConfig) -> Tuple[str, str]:
     """
     Classify apostrophe usage and propose normalized form.
@@ -1398,11 +1473,15 @@ def classify_token(token: str, cfg: ApostropheConfig) -> Tuple[str, str]:
             return _case_preserving_words(token, words)
 
         collapse_value = token.replace("'", "")
-        normalized = _apply_contraction_policy(token, category=category, cfg=cfg, expand=_expand, collapse=collapse_value)
+        normalized = _apply_contraction_policy(
+            token, category=category, cfg=cfg, expand=_expand, collapse=collapse_value
+        )
         return category, normalized
 
     # 6. Suffix contractions ('m handled separately)
-    if low.endswith("'m") and low[:-2] in SUFFIX_CONTRACTION_BASES.get("'m", ()):  # pronoun I'm
+    if low.endswith("'m") and low[:-2] in SUFFIX_CONTRACTION_BASES.get(
+        "'m", ()
+    ):  # pronoun I'm
 
         def _expand_m() -> str:
             base = token[:-2]
@@ -1488,7 +1567,10 @@ def classify_token(token: str, cfg: ApostropheConfig) -> Tuple[str, str]:
         return "other", token.replace("'", cfg.joiner)
     return "other", token
 
-def normalize_apostrophes(text: str, cfg: ApostropheConfig | None = None) -> Tuple[str, List[Tuple[str,str,str]]]:
+
+def normalize_apostrophes(
+    text: str, cfg: ApostropheConfig | None = None
+) -> Tuple[str, List[Tuple[str, str, str]]]:
     """
     Normalize apostrophes per config.
     Returns normalized text AND a list of (original_token, category, normalized_token)
@@ -1502,7 +1584,10 @@ def normalize_apostrophes(text: str, cfg: ApostropheConfig | None = None) -> Tup
     token_entries = tokenize_with_spans(text)
 
     use_contextual_s = cfg.contraction_mode == "expand"
-    use_contextual_d = cfg.contraction_mode == "expand" and cfg.ambiguous_past_modal_mode == "contextual"
+    use_contextual_d = (
+        cfg.contraction_mode == "expand"
+        and cfg.ambiguous_past_modal_mode == "contextual"
+    )
 
     need_contextual = False
     if (use_contextual_s or use_contextual_d) and token_entries:
@@ -1514,7 +1599,9 @@ def normalize_apostrophes(text: str, cfg: ApostropheConfig | None = None) -> Tup
                 need_contextual = True
                 break
 
-    contextual_resolutions = resolve_ambiguous_contractions(text) if need_contextual else {}
+    contextual_resolutions = (
+        resolve_ambiguous_contractions(text) if need_contextual else {}
+    )
 
     results: List[Tuple[str, str, str]] = []
     normalized_tokens: List[str] = []
@@ -1522,7 +1609,9 @@ def normalize_apostrophes(text: str, cfg: ApostropheConfig | None = None) -> Tup
     for tok, start, end in token_entries:
         category, norm = classify_token(tok, cfg)
 
-        resolution = contextual_resolutions.get((start, end)) if contextual_resolutions else None
+        resolution = (
+            contextual_resolutions.get((start, end)) if contextual_resolutions else None
+        )
         if resolution is not None and cfg.contraction_mode == "expand":
             if cfg.is_contraction_enabled(resolution.category):
                 category = resolution.category
@@ -1537,6 +1626,7 @@ def normalize_apostrophes(text: str, cfg: ApostropheConfig | None = None) -> Tup
     normalized_text = _cleanup_spacing(" ".join(filtered))
     return normalized_text, results
 
+
 def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
     if not text:
         return text
@@ -1609,14 +1699,14 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
 
             first_two = value // 100
             last_two = value % 100
-            
+
             prefix = _words(first_two)
             if not prefix:
                 return None
 
             if last_two == 0:
                 return f"{prefix} hundred"
-            
+
             if last_two < 10:
                 # Use "oh X" format (e.g. "nineteen oh five")
                 return f"{prefix} oh {_DIGIT_WORDS[last_two]}"
@@ -1673,9 +1763,11 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
 
         # Check for "address" or "addresses" as a whole word
         has_address = bool(re.search(r"\baddress(es)?\b", context))
-        
+
         # Check for year markers as whole words
-        has_year_marker = bool(re.search(r"\b(bc|ad|bce|ce|b\.c\.|a\.d\.|b\.c\.e\.|c\.e\.)\b", context))
+        has_year_marker = bool(
+            re.search(r"\b(bc|ad|bce|ce|b\.c\.|a\.d\.|b\.c\.e\.|c\.e\.)\b", context)
+        )
 
         should_try_year = True
         if has_address and not has_year_marker:
@@ -1740,7 +1832,7 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
     def _replace_currency(match: re.Match[str]) -> str:
         if num2words is None:
             return match.group(0)
-            
+
         symbol = match.group("symbol")
         amount_str = match.group("amount").replace(",", "")
         magnitude = match.group("magnitude")
@@ -1756,17 +1848,17 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
                 integer_part, fraction_part = amount_str.split(".", 1)
                 integer_val = int(integer_part)
                 integer_words = _int_to_words(integer_val, language)
-                
+
                 # Spell out fraction digits
                 digit_words = []
                 for digit in fraction_part:
                     if digit.isdigit():
                         digit_words.append(_DIGIT_WORDS[int(digit)])
-                
+
                 amount_spoken = f"{integer_words} point {' '.join(digit_words)}"
             else:
                 amount_spoken = _int_to_words(int(amount), language)
-            
+
             currency_names = {
                 "$": "dollars",
                 "£": "pounds",
@@ -1774,7 +1866,7 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
                 "¥": "yen",
             }
             currency_name = currency_names.get(symbol, "dollars")
-            
+
             return f"{amount_spoken} {magnitude} {currency_name}"
 
         # Handle $0.99 -> ninety-nine cents (avoid "zero dollars and...").
@@ -1787,7 +1879,9 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
                 except ValueError:
                     cents_value = 0
                 if cents_value > 0:
-                    cents_words = _int_to_words(cents_value, language) or str(cents_value)
+                    cents_words = _int_to_words(cents_value, language) or str(
+                        cents_value
+                    )
                     subunit = {
                         "$": "cent",
                         "€": "cent",
@@ -1797,7 +1891,11 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
                     if symbol == "£":
                         subunit = "pence" if cents_value != 1 else "penny"
                     else:
-                        subunit = (subunit + "s") if cents_value != 1 and subunit not in {"pence", "yen"} else subunit
+                        subunit = (
+                            (subunit + "s")
+                            if cents_value != 1 and subunit not in {"pence", "yen"}
+                            else subunit
+                        )
                     return f"{cents_words} {subunit}".strip()
 
         currency_map = {
@@ -1807,12 +1905,14 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
             "¥": "JPY",
         }
         currency_code = currency_map.get(symbol, "USD")
-        
+
         try:
             # Always use float to avoid num2words treating int as cents (if that's what it does)
             # or to ensure consistent behavior.
-            words = num2words(amount, to="currency", currency=currency_code, lang=language)
-            
+            words = num2words(
+                amount, to="currency", currency=currency_code, lang=language
+            )
+
             # Remove "zero cents" if present
             # Patterns: ", zero cents", " and zero cents"
             words = words.replace(", zero cents", "").replace(" and zero cents", "")
@@ -1829,21 +1929,21 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
             parts = [p for p in domain.split(".") if p]
             if parts and all(p.isalpha() and len(p) <= 2 for p in parts):
                 return match.group(0)
-        
+
         # Avoid matching numbers like 1.05 or 12.34.56
         # If the domain consists only of digits and dots, ignore it (unless it has http/www prefix)
         has_prefix = match.group(1) or match.group(2)
-        if not has_prefix and all(c.isdigit() or c == '.' or c == '-' for c in domain):
-             # Check if it really looks like a number (e.g. 1.05)
-             # If it has multiple dots like 1.2.3.4 it might be an IP, which we might want to speak as dot?
-             # But 1.05 is definitely a number.
-             # Let's be safe: if it looks like a float, skip.
-             try:
-                 float(domain)
-                 return match.group(0)
-             except ValueError:
-                 pass
-        
+        if not has_prefix and all(c.isdigit() or c == "." or c == "-" for c in domain):
+            # Check if it really looks like a number (e.g. 1.05)
+            # If it has multiple dots like 1.2.3.4 it might be an IP, which we might want to speak as dot?
+            # But 1.05 is definitely a number.
+            # Let's be safe: if it looks like a float, skip.
+            try:
+                float(domain)
+                return match.group(0)
+            except ValueError:
+                pass
+
         if domain.startswith("www."):
             domain = domain[4:]
         spoken = domain.replace(".", " dot ")
@@ -1865,15 +1965,23 @@ def _normalize_grouped_numbers(text: str, cfg: ApostropheConfig) -> str:
         normalized = _CURRENCY_RE.sub(_replace_currency, normalized)
 
     if cfg.convert_numbers:
-        normalized = _NUMBER_RANGE_RE.sub(lambda m: _replace_number_range(m, language), normalized)
-        normalized = _NUMBER_SPACE_RANGE_RE.sub(lambda m: _replace_space_separated_range(m, language), normalized)
-        normalized = _FRACTION_RE.sub(lambda m: _replace_fraction(m, language), normalized)
+        normalized = _NUMBER_RANGE_RE.sub(
+            lambda m: _replace_number_range(m, language), normalized
+        )
+        normalized = _NUMBER_SPACE_RANGE_RE.sub(
+            lambda m: _replace_space_separated_range(m, language), normalized
+        )
+        normalized = _FRACTION_RE.sub(
+            lambda m: _replace_fraction(m, language), normalized
+        )
         normalized = _DECIMAL_NUMBER_RE.sub(_replace_decimal, normalized)
         normalized = _NUMBER_WITH_GROUP_RE.sub(_replace_grouped, normalized)
         normalized = _PLAIN_NUMBER_RE.sub(_replace_plain, normalized)
         normalized = _normalize_roman_numerals(normalized, language)
 
     return normalized
+
+
 def _normalize_dotted_acronyms(text: str) -> str:
     def _replace(match: re.Match[str]) -> str:
         value = match.group(0)
@@ -1882,8 +1990,10 @@ def _normalize_dotted_acronyms(text: str) -> str:
 
     return re.sub(r"\b(?:[A-Z]\.){1,}[A-Z]\.?(?=\W|$)", _replace, text)
 
+
 # ---------- Optional phoneme hint post-processing ----------
 
+
 def apply_phoneme_hints(text: str, iz_marker="‹IZ›") -> str:
     """
     Replace markers with an orthographic sequence that
@@ -1951,7 +2061,10 @@ _LLM_REGEX_TOOL = {
         },
     },
 }
-_LLM_REGEX_TOOL_CHOICE = {"type": "function", "function": {"name": _LLM_REGEX_TOOL_NAME}}
+_LLM_REGEX_TOOL_CHOICE = {
+    "type": "function",
+    "function": {"name": _LLM_REGEX_TOOL_NAME},
+}
 _LLM_ALLOWED_REGEX_FLAGS = {
     "IGNORECASE": re.IGNORECASE,
     "MULTILINE": re.MULTILINE,
@@ -1974,7 +2087,9 @@ _SENTENCE_CAPTURE_RE = re.compile(r"[^.!?]+[.!?]+|[^.!?]+$", re.MULTILINE)
 
 
 def _split_sentences_for_llm(text: str) -> List[str]:
-    sentences = [segment.strip() for segment in _SENTENCE_CAPTURE_RE.findall(text or "")]
+    sentences = [
+        segment.strip() for segment in _SENTENCE_CAPTURE_RE.findall(text or "")
+    ]
     return [segment for segment in sentences if segment]
 
 
@@ -1984,7 +2099,10 @@ def _normalize_with_llm(
     settings: Mapping[str, Any],
     config: ApostropheConfig,
 ) -> str:
-    from abogen.normalization_settings import build_llm_configuration, DEFAULT_LLM_PROMPT
+    from abogen.normalization_settings import (
+        build_llm_configuration,
+        DEFAULT_LLM_PROMPT,
+    )
     from abogen.llm_client import generate_completion, LLMClientError
 
     llm_config = build_llm_configuration(settings)
@@ -2001,7 +2119,7 @@ def _normalize_with_llm(
         newline = ""
         if raw_line.endswith(("\r", "\n")):
             stripped_newline = raw_line.rstrip("\r\n")
-            newline = raw_line[len(stripped_newline):]
+            newline = raw_line[len(stripped_newline) :]
             line_body = stripped_newline
         else:
             line_body = raw_line
@@ -2011,7 +2129,7 @@ def _normalize_with_llm(
             continue
 
         leading_ws = line_body[: len(line_body) - len(line_body.lstrip())]
-        trailing_ws = line_body[len(line_body.rstrip()):]
+        trailing_ws = line_body[len(line_body.rstrip()) :]
         core = line_body[len(leading_ws) : len(line_body) - len(trailing_ws)]
 
         sentences = _split_sentences_for_llm(core)
@@ -2136,7 +2254,11 @@ def _normalize_flag_field(raw: Any) -> List[str]:
     seen: set[str] = set()
     for value in raw_iterable:
         candidate = str(value or "").strip().upper()
-        if not candidate or candidate not in _LLM_ALLOWED_REGEX_FLAGS or candidate in seen:
+        if (
+            not candidate
+            or candidate not in _LLM_ALLOWED_REGEX_FLAGS
+            or candidate in seen
+        ):
             continue
         seen.add(candidate)
         normalized.append(candidate)
@@ -2153,7 +2275,9 @@ def _apply_single_regex_replacement(text: str, spec: Mapping[str, Any]) -> str:
     flag_names = spec.get("flags")
     if isinstance(flag_names, str):
         flag_iterable: Iterable[Any] = [flag_names]
-    elif isinstance(flag_names, Iterable) and not isinstance(flag_names, (bytes, str, Mapping)):
+    elif isinstance(flag_names, Iterable) and not isinstance(
+        flag_names, (bytes, str, Mapping)
+    ):
         flag_iterable = flag_names
     else:
         flag_iterable = []
@@ -2179,7 +2303,10 @@ def normalize_for_pipeline(
 ) -> str:
     """Normalize text for the synthesis pipeline with runtime settings."""
 
-    from abogen.normalization_settings import build_apostrophe_config, get_runtime_settings
+    from abogen.normalization_settings import (
+        build_apostrophe_config,
+        get_runtime_settings,
+    )
     from abogen.llm_client import LLMClientError
 
     runtime_settings = settings or get_runtime_settings()
@@ -2201,15 +2328,25 @@ def normalize_for_pipeline(
 
     if mode == "off":
         normalized = normalize_unicode_apostrophes(normalized)
-        if cfg.convert_numbers or cfg.convert_currency or getattr(cfg, "remove_footnotes", False):
+        if (
+            cfg.convert_numbers
+            or cfg.convert_currency
+            or getattr(cfg, "remove_footnotes", False)
+        ):
             normalized = _normalize_grouped_numbers(normalized, cfg)
         normalized = _cleanup_spacing(normalized)
     elif mode == "llm":
         try:
-            normalized = _normalize_with_llm(normalized, settings=runtime_settings, config=cfg)
+            normalized = _normalize_with_llm(
+                normalized, settings=runtime_settings, config=cfg
+            )
         except LLMClientError:
             raise
-        if cfg.convert_numbers or cfg.convert_currency or getattr(cfg, "remove_footnotes", False):
+        if (
+            cfg.convert_numbers
+            or cfg.convert_currency
+            or getattr(cfg, "remove_footnotes", False)
+        ):
             normalized = _normalize_grouped_numbers(normalized, cfg)
         normalized = _cleanup_spacing(normalized)
     else:
@@ -2227,6 +2364,7 @@ def normalize_for_pipeline(
 
     return normalized
 
+
 # ---------- Example Usage ----------
 
 if __name__ == "__main__":
@@ -2237,4 +2375,4 @@ if __name__ == "__main__":
     print("Original:", sample)
     print("Normalized:", norm_text)
     for orig, cat, norm in details:
-        print(f"{orig:15} -> {norm:15} [{cat}]")
\ No newline at end of file
+        print(f"{orig:15} -> {norm:15} [{cat}]")
diff --git a/abogen/llm_client.py b/abogen/llm_client.py
index b6c075b..2937fa3 100644
--- a/abogen/llm_client.py
+++ b/abogen/llm_client.py
@@ -52,8 +52,10 @@ def _build_url(base_url: str, path: str) -> str:
     normalized = _normalized_base_url(base_url)
     trimmed_path = path.lstrip("/")
     parsed = parse.urlparse(normalized)
-    if parsed.path.rstrip("/").lower().endswith("/v1") and trimmed_path.startswith("v1/"):
-        trimmed_path = trimmed_path[len("v1/"):]
+    if parsed.path.rstrip("/").lower().endswith("/v1") and trimmed_path.startswith(
+        "v1/"
+    ):
+        trimmed_path = trimmed_path[len("v1/") :]
     return parse.urljoin(normalized, trimmed_path)
 
 
@@ -77,7 +79,9 @@ def _perform_request(
     if payload is not None:
         data_bytes = json.dumps(payload).encode("utf-8")
     request_headers = dict(headers or {})
-    req = request.Request(url, data=data_bytes, headers=request_headers, method=method.upper())
+    req = request.Request(
+        url, data=data_bytes, headers=request_headers, method=method.upper()
+    )
     try:
         with request.urlopen(req, timeout=timeout) as response:
             body = response.read()
@@ -102,7 +106,9 @@ def list_models(configuration: LLMConfiguration) -> List[Dict[str, str]]:
         raise LLMClientError("LLM configuration is incomplete")
     url = _build_url(configuration.base_url, "v1/models")
     headers = _build_headers(configuration.api_key)
-    payload = _perform_request("GET", url, headers=headers, timeout=configuration.timeout)
+    payload = _perform_request(
+        "GET", url, headers=headers, timeout=configuration.timeout
+    )
     if not isinstance(payload, Mapping):
         raise LLMClientError("Unexpected response when listing models")
     data = payload.get("data")
@@ -153,7 +159,9 @@ def generate_completion(
     if response_format:
         payload["response_format"] = dict(response_format)
 
-    response = _perform_request("POST", url, headers=headers, payload=payload, timeout=configuration.timeout)
+    response = _perform_request(
+        "POST", url, headers=headers, payload=payload, timeout=configuration.timeout
+    )
     if not isinstance(response, Mapping):
         raise LLMClientError("Unexpected response from LLM")
     choices = response.get("choices")
diff --git a/abogen/normalization_settings.py b/abogen/normalization_settings.py
index fcbe58e..4242265 100644
--- a/abogen/normalization_settings.py
+++ b/abogen/normalization_settings.py
@@ -5,7 +5,10 @@ from dataclasses import replace
 from functools import lru_cache
 from typing import Any, Dict, Mapping, Optional
 
-from abogen.kokoro_text_normalization import ApostropheConfig, CONTRACTION_CATEGORY_DEFAULTS
+from abogen.kokoro_text_normalization import (
+    ApostropheConfig,
+    CONTRACTION_CATEGORY_DEFAULTS,
+)
 from abogen.llm_client import LLMConfiguration
 from abogen.utils import load_config
 
@@ -149,7 +152,9 @@ def _extract_settings(source: Mapping[str, Any]) -> Dict[str, Any]:
         elif isinstance(default, float):
             extracted[key] = _coerce_float(raw_value, default)
         else:
-            extracted[key] = str(raw_value or "") if isinstance(default, str) else raw_value
+            extracted[key] = (
+                str(raw_value or "") if isinstance(default, str) else raw_value
+            )
     _apply_llm_migrations(extracted)
     return extracted
 
@@ -177,20 +182,38 @@ def build_apostrophe_config(
     config.convert_numbers = bool(settings.get("normalization_numbers", True))
     config.convert_currency = bool(settings.get("normalization_currency", True))
     config.remove_footnotes = bool(settings.get("normalization_footnotes", True))
-    config.year_pronunciation_mode = str(settings.get("normalization_numbers_year_style", "american") or "").strip().lower()
+    config.year_pronunciation_mode = (
+        str(settings.get("normalization_numbers_year_style", "american") or "")
+        .strip()
+        .lower()
+    )
     config.add_phoneme_hints = bool(settings.get("normalization_phoneme_hints", True))
-    config.contraction_mode = "expand" if settings.get("normalization_apostrophes_contractions", True) else "keep"
+    config.contraction_mode = (
+        "expand"
+        if settings.get("normalization_apostrophes_contractions", True)
+        else "keep"
+    )
     config.plural_possessive_mode = (
-        "collapse" if settings.get("normalization_apostrophes_plural_possessives", True) else "keep"
+        "collapse"
+        if settings.get("normalization_apostrophes_plural_possessives", True)
+        else "keep"
     )
     config.sibilant_possessive_mode = (
-        "mark" if settings.get("normalization_apostrophes_sibilant_possessives", True) else "keep"
+        "mark"
+        if settings.get("normalization_apostrophes_sibilant_possessives", True)
+        else "keep"
+    )
+    config.decades_mode = (
+        "expand" if settings.get("normalization_apostrophes_decades", True) else "keep"
     )
-    config.decades_mode = "expand" if settings.get("normalization_apostrophes_decades", True) else "keep"
     config.leading_elision_mode = (
-        "expand" if settings.get("normalization_apostrophes_leading_elisions", True) else "keep"
+        "expand"
+        if settings.get("normalization_apostrophes_leading_elisions", True)
+        else "keep"
+    )
+    config.ambiguous_past_modal_mode = (
+        "contextual" if config.contraction_mode == "expand" else "keep"
     )
-    config.ambiguous_past_modal_mode = "contextual" if config.contraction_mode == "expand" else "keep"
     category_flags = dict(CONTRACTION_CATEGORY_DEFAULTS)
     for setting_key, category in _CONTRACTION_SETTING_MAP.items():
         default_value = bool(_SETTINGS_DEFAULTS.get(setting_key, True))
@@ -205,11 +228,15 @@ def build_llm_configuration(settings: Mapping[str, Any]) -> LLMConfiguration:
         base_url=str(settings.get("llm_base_url") or ""),
         api_key=str(settings.get("llm_api_key") or ""),
         model=str(settings.get("llm_model") or ""),
-        timeout=_coerce_float(settings.get("llm_timeout"), float(_SETTINGS_DEFAULTS["llm_timeout"])),
+        timeout=_coerce_float(
+            settings.get("llm_timeout"), float(_SETTINGS_DEFAULTS["llm_timeout"])
+        ),
     )
 
 
-def apply_overrides(base: Mapping[str, Any], overrides: Mapping[str, Any]) -> Dict[str, Any]:
+def apply_overrides(
+    base: Mapping[str, Any], overrides: Mapping[str, Any]
+) -> Dict[str, Any]:
     merged: Dict[str, Any] = dict(base)
     for key, value in overrides.items():
         if key not in _SETTINGS_DEFAULTS:
diff --git a/abogen/pronunciation_store.py b/abogen/pronunciation_store.py
index 19e7f33..5a5e7fb 100644
--- a/abogen/pronunciation_store.py
+++ b/abogen/pronunciation_store.py
@@ -31,7 +31,7 @@ def _migrate_legacy_sqlite(target_json_path: Path) -> None:
         base_dir = Path(get_user_settings_dir())
     except ModuleNotFoundError:
         base_dir = Path(get_internal_cache_path("pronunciations"))
-    
+
     sqlite_path = base_dir / "pronunciations.db"
     if not sqlite_path.exists():
         return
@@ -39,23 +39,25 @@ def _migrate_legacy_sqlite(target_json_path: Path) -> None:
     try:
         conn = sqlite3.connect(sqlite_path)
         conn.row_factory = sqlite3.Row
-        
+
         # Check if table exists
-        cursor = conn.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='overrides'")
+        cursor = conn.execute(
+            "SELECT name FROM sqlite_master WHERE type='table' AND name='overrides'"
+        )
         if not cursor.fetchone():
             conn.close()
             return
 
         cursor = conn.execute("SELECT * FROM overrides")
         rows = cursor.fetchall()
-        
+
         data = {"version": _SCHEMA_VERSION, "overrides": {}}
-        
+
         for row in rows:
             lang = row["language"]
             if lang not in data["overrides"]:
                 data["overrides"][lang] = {}
-            
+
             entry = {
                 "id": str(row["id"]),
                 "normalized": row["normalized"],
@@ -70,16 +72,16 @@ def _migrate_legacy_sqlite(target_json_path: Path) -> None:
                 "updated_at": row["updated_at"],
             }
             data["overrides"][lang][row["normalized"]] = entry
-            
+
         conn.close()
-        
+
         # Save to JSON
         with open(target_json_path, "w", encoding="utf-8") as f:
             json.dump(data, f, indent=2, ensure_ascii=False)
-            
+
         # Rename old DB
         sqlite_path.rename(sqlite_path.with_suffix(".db.bak"))
-        
+
     except Exception:
         pass
 
@@ -110,11 +112,11 @@ def load_overrides(language: str, tokens: Iterable[str]) -> Dict[str, Dict[str,
     normalized_tokens = {normalize_token(token) for token in tokens if token}
     if not normalized_tokens:
         return {}
-    
+
     with _DB_LOCK:
         db = _load_db()
         lang_overrides = db.get("overrides", {}).get(language, {})
-        
+
         results: Dict[str, Dict[str, Any]] = {}
         for normalized in normalized_tokens:
             if normalized in lang_overrides:
@@ -122,22 +124,27 @@ def load_overrides(language: str, tokens: Iterable[str]) -> Dict[str, Dict[str,
         return results
 
 
-def search_overrides(language: str, query: str, *, limit: int = 15) -> List[Dict[str, Any]]:
+def search_overrides(
+    language: str, query: str, *, limit: int = 15
+) -> List[Dict[str, Any]]:
     if not query:
         return []
-    
+
     query = query.lower()
     with _DB_LOCK:
         db = _load_db()
         lang_overrides = db.get("overrides", {}).get(language, {})
-        
+
         matches = []
         for entry in lang_overrides.values():
             if query in entry["normalized"] or query in entry["token"].lower():
                 matches.append(entry)
-        
+
         # Sort by usage count desc, then updated_at desc
-        matches.sort(key=lambda x: (x.get("usage_count", 0), x.get("updated_at", 0)), reverse=True)
+        matches.sort(
+            key=lambda x: (x.get("usage_count", 0), x.get("updated_at", 0)),
+            reverse=True,
+        )
         return matches[:limit]
 
 
@@ -153,15 +160,15 @@ def save_override(
     normalized = normalize_token(token)
     if not normalized:
         raise ValueError("Provide a token to override")
-    
+
     timestamp = time.time()
     with _DB_LOCK:
         db = _load_db()
         overrides = db.setdefault("overrides", {})
         lang_overrides = overrides.setdefault(language, {})
-        
+
         existing = lang_overrides.get(normalized)
-        
+
         if existing:
             entry = existing
             entry["token"] = token
@@ -185,7 +192,7 @@ def save_override(
                 "updated_at": timestamp,
             }
             lang_overrides[normalized] = entry
-            
+
         _save_db(db)
         return entry
 
@@ -194,11 +201,11 @@ def delete_override(*, language: str, token: str) -> None:
     normalized = normalize_token(token)
     if not normalized:
         return
-    
+
     with _DB_LOCK:
         db = _load_db()
         lang_overrides = db.get("overrides", {}).get(language, {})
-        
+
         if normalized in lang_overrides:
             del lang_overrides[normalized]
             _save_db(db)
@@ -208,7 +215,7 @@ def all_overrides(language: str) -> List[Dict[str, Any]]:
     with _DB_LOCK:
         db = _load_db()
         lang_overrides = db.get("overrides", {}).get(language, {})
-        
+
         results = list(lang_overrides.values())
         results.sort(key=lambda x: x.get("updated_at", 0), reverse=True)
         return results
@@ -218,11 +225,11 @@ def increment_usage(*, language: str, token: str, amount: int = 1) -> None:
     normalized = normalize_token(token)
     if not normalized:
         return
-    
+
     with _DB_LOCK:
         db = _load_db()
         lang_overrides = db.get("overrides", {}).get(language, {})
-        
+
         if normalized in lang_overrides:
             entry = lang_overrides[normalized]
             entry["usage_count"] = entry.get("usage_count", 0) + amount
@@ -234,11 +241,13 @@ def get_override_stats(language: str) -> Dict[str, int]:
     with _DB_LOCK:
         db = _load_db()
         lang_overrides = db.get("overrides", {}).get(language, {})
-        
+
         total = len(lang_overrides)
-        with_pronunciation = sum(1 for x in lang_overrides.values() if x.get("pronunciation"))
+        with_pronunciation = sum(
+            1 for x in lang_overrides.values() if x.get("pronunciation")
+        )
         with_voice = sum(1 for x in lang_overrides.values() if x.get("voice"))
-        
+
         return {
             "total": total,
             "filtered": total,
diff --git a/abogen/spacy_contraction_resolver.py b/abogen/spacy_contraction_resolver.py
index d85ca7e..7a95704 100644
--- a/abogen/spacy_contraction_resolver.py
+++ b/abogen/spacy_contraction_resolver.py
@@ -49,7 +49,9 @@ def _load_spacy_model(model: str = _DEFAULT_MODEL) -> Optional[Language]:
     return nlp
 
 
-def resolve_ambiguous_contractions(text: str, *, model: Optional[str] = None) -> Dict[Tuple[int, int], ContractionResolution]:
+def resolve_ambiguous_contractions(
+    text: str, *, model: Optional[str] = None
+) -> Dict[Tuple[int, int], ContractionResolution]:
     """Use spaCy to disambiguate ambiguous contractions in *text*.
 
     Returns a mapping from (start, end) spans to their resolved expansion.
@@ -80,7 +82,9 @@ def resolve_ambiguous_contractions(text: str, *, model: Optional[str] = None) ->
     return resolutions
 
 
-def _resolution(prev: Token, token: Token, expansion_word: str, category: str, lemma_hint: str) -> Optional[ContractionResolution]:
+def _resolution(
+    prev: Token, token: Token, expansion_word: str, category: str, lemma_hint: str
+) -> Optional[ContractionResolution]:
     if token is None or prev is None:
         return None
 
@@ -186,10 +190,14 @@ def _resolve_apostrophe_d(token: Token) -> Optional[ContractionResolution]:
         next_lemma = ""
 
     if next_tag == "VB":
-        return _resolution(prev, token, "would", "contraction_modal_would", lemma or "will")
+        return _resolution(
+            prev, token, "would", "contraction_modal_would", lemma or "will"
+        )
 
     if token.tag_ == "MD" or lemma in {"will", "would", "shall"}:
-        return _resolution(prev, token, "would", "contraction_modal_would", lemma or "will")
+        return _resolution(
+            prev, token, "would", "contraction_modal_would", lemma or "will"
+        )
 
     if next_lemma in {"been", "gone", "had", "better"} or next_tag in {"VBN", "VBD"}:
         return _resolution(prev, token, "had", "contraction_aux_have", "have")
@@ -255,4 +263,3 @@ def _context_prefers_had(token: Token) -> bool:
     if next_lemma == "better":
         return True
     return False
-
diff --git a/abogen/spacy_utils.py b/abogen/spacy_utils.py
index 54fbcf7..46d6510 100644
--- a/abogen/spacy_utils.py
+++ b/abogen/spacy_utils.py
@@ -83,12 +83,12 @@ def get_spacy_model(lang_code, log_callback=None):
             model_name,
             disable=["ner", "tagger", "lemmatizer", "attribute_ruler"],
         )
-        
+
         # Ensure a sentence segmentation strategy is in place
         # The parser provides sents, but if it's missing (unlikely for core models), fallback to sentencizer
         if "parser" not in nlp.pipe_names and "sentencizer" not in nlp.pipe_names:
             nlp.add_pipe("sentencizer")
-            
+
         _nlp_cache[lang_code] = nlp
         return nlp
     except OSError:
@@ -105,7 +105,7 @@ def get_spacy_model(lang_code, log_callback=None):
             )
             if "parser" not in nlp.pipe_names and "sentencizer" not in nlp.pipe_names:
                 nlp.add_pipe("sentencizer")
-                
+
             _nlp_cache[lang_code] = nlp
             log(f"spaCy model '{model_name}' downloaded and loaded")
             return nlp
diff --git a/abogen/speaker_analysis.py b/abogen/speaker_analysis.py
index 40a7d66..e8d0b09 100644
--- a/abogen/speaker_analysis.py
+++ b/abogen/speaker_analysis.py
@@ -164,10 +164,16 @@ class SpeakerGuess:
         sample_excerpt: Optional[str] = None,
     ) -> None:
         self.count += 1
-        if _CONFIDENCE_RANK.get(confidence, 0) > _CONFIDENCE_RANK.get(self.confidence, 0):
+        if _CONFIDENCE_RANK.get(confidence, 0) > _CONFIDENCE_RANK.get(
+            self.confidence, 0
+        ):
             self.confidence = confidence
 
-        excerpt = sample_excerpt if sample_excerpt is not None else _build_excerpt(text, quote)
+        excerpt = (
+            sample_excerpt
+            if sample_excerpt is not None
+            else _build_excerpt(text, quote)
+        )
         gender_hint = _format_gender_hint(male_votes, female_votes)
         if excerpt:
             payload = {"excerpt": excerpt, "gender_hint": gender_hint}
@@ -180,9 +186,13 @@ class SpeakerGuess:
             self.male_votes += male_votes
         if female_votes:
             self.female_votes += female_votes
-        self.detected_gender = _derive_gender(self.male_votes, self.female_votes, self.detected_gender)
+        self.detected_gender = _derive_gender(
+            self.male_votes, self.female_votes, self.detected_gender
+        )
         if self.gender in {"unknown", "male", "female"}:
-            self.gender = _derive_gender(self.male_votes, self.female_votes, self.gender)
+            self.gender = _derive_gender(
+                self.male_votes, self.female_votes, self.gender
+            )
 
     def as_dict(self) -> Dict[str, Any]:
         return {
@@ -211,7 +221,10 @@ class SpeakerAnalysis:
             "version": self.version,
             "narrator": self.narrator,
             "assignments": dict(self.assignments),
-            "speakers": {speaker_id: guess.as_dict() for speaker_id, guess in self.speakers.items()},
+            "speakers": {
+                speaker_id: guess.as_dict()
+                for speaker_id, guess in self.speakers.items()
+            },
             "suppressed": list(self.suppressed),
             "stats": dict(self.stats),
         }
@@ -226,7 +239,9 @@ def analyze_speakers(
 ) -> SpeakerAnalysis:
     narrator_id = "narrator"
     speaker_guesses: Dict[str, SpeakerGuess] = {
-        narrator_id: SpeakerGuess(speaker_id=narrator_id, label="Narrator", confidence="low")
+        narrator_id: SpeakerGuess(
+            speaker_id=narrator_id, label="Narrator", confidence="low"
+        )
     }
     label_index: Dict[str, str] = {"Narrator": narrator_id}
     assignments: Dict[str, str] = {}
@@ -265,21 +280,31 @@ def analyze_speakers(
             if record_id is None:
                 record_id = _dedupe_slug(_slugify(label), speaker_guesses)
                 label_index[label] = record_id
-                speaker_guesses[record_id] = SpeakerGuess(speaker_id=record_id, label=label)
+                speaker_guesses[record_id] = SpeakerGuess(
+                    speaker_id=record_id, label=label
+                )
             guess = speaker_guesses[record_id]
         assignments[chunk_id] = record_id
         unique_speakers.add(record_id)
 
-        if record_id != narrator_id and record_id != speaker_id and speaker_id == last_explicit:
+        if (
+            record_id != narrator_id
+            and record_id != speaker_id
+            and speaker_id == last_explicit
+        ):
             last_explicit = record_id
 
         sample_excerpt = None
         if record_id != narrator_id:
-            sample_excerpt = _select_sample_excerpt(ordered_chunks, index, guess.label, quote, confidence)
+            sample_excerpt = _select_sample_excerpt(
+                ordered_chunks, index, guess.label, quote, confidence
+            )
 
         male_votes, female_votes = _count_gender_votes(text, guess.label)
 
-        guess.register_occurrence(confidence, text, quote, male_votes, female_votes, sample_excerpt)
+        guess.register_occurrence(
+            confidence, text, quote, male_votes, female_votes, sample_excerpt
+        )
 
     active_speakers = [sid for sid in speaker_guesses if sid != narrator_id]
     # Apply minimum occurrence threshold.
@@ -302,7 +327,9 @@ def analyze_speakers(
         active_speakers = active_speakers[:max_speakers]
 
     narrator_guess = speaker_guesses[narrator_id]
-    narrator_guess.count = sum(1 for value in assignments.values() if value == narrator_id)
+    narrator_guess.count = sum(
+        1 for value in assignments.values() if value == narrator_id
+    )
     narrator_guess.confidence = "low"
 
     stats = {
@@ -322,7 +349,9 @@ def analyze_speakers(
     )
 
 
-def _infer_chunk_speaker(text: str, last_explicit: Optional[str]) -> Tuple[Optional[str], str, Optional[str]]:
+def _infer_chunk_speaker(
+    text: str, last_explicit: Optional[str]
+) -> Tuple[Optional[str], str, Optional[str]]:
     normalized = text.strip()
     if not normalized:
         return None, "low", None
@@ -376,7 +405,9 @@ def _match_name_near_quote(before: str, after: str) -> Optional[str]:
         if _looks_like_name(name):
             return name
 
-    match = re.search(rf"({_NAME_PATTERN})\s*,?\s*{_VERB_PATTERN}", leading, flags=re.IGNORECASE)
+    match = re.search(
+        rf"({_NAME_PATTERN})\s*,?\s*{_VERB_PATTERN}", leading, flags=re.IGNORECASE
+    )
     if match:
         name = match.group(1)
         if _looks_like_name(name):
@@ -466,8 +497,14 @@ def _count_gender_votes(text: str, label: Optional[str]) -> Tuple[int, int]:
                 if windows:
                     mapped: List[Tuple[int, int]] = []
                     for start, end in windows:
-                        start_idx = min(len(search_text) - 1, int(start * len(search_text) / max(len(ascii_text), 1)))
-                        end_idx = min(len(search_text), int(end * len(search_text) / max(len(ascii_text), 1)))
+                        start_idx = min(
+                            len(search_text) - 1,
+                            int(start * len(search_text) / max(len(ascii_text), 1)),
+                        )
+                        end_idx = min(
+                            len(search_text),
+                            int(end * len(search_text) / max(len(ascii_text), 1)),
+                        )
                         mapped.append((start_idx, end_idx))
                     windows = mapped
         else:
@@ -485,7 +522,9 @@ def _count_gender_votes(text: str, label: Optional[str]) -> Tuple[int, int]:
         except IndexError:
             content_start, content_end = match.span()
         if content_start < content_end:
-            quote_spans.append((content_start, content_end, search_text[content_start:content_end]))
+            quote_spans.append(
+                (content_start, content_end, search_text[content_start:content_end])
+            )
 
     normalized_label = _normalize_candidate_name(label) if label else None
     normalized_label_lower = normalized_label.lower() if normalized_label else None
@@ -511,7 +550,11 @@ def _count_gender_votes(text: str, label: Optional[str]) -> Tuple[int, int]:
             name_matches = list(re.finditer(_NAME_PATTERN, tail))
             if name_matches:
                 last_name = _normalize_candidate_name(name_matches[-1].group(0))
-                if normalized_label_lower and last_name and last_name.lower() == normalized_label_lower:
+                if (
+                    normalized_label_lower
+                    and last_name
+                    and last_name.lower() == normalized_label_lower
+                ):
                     return 0.6
                 return 0.05
             if re.search(r"[.!?]\s", prefix):
@@ -607,8 +650,12 @@ def _contains_dialogue_attribution(label: str, text: str, quote: Optional[str])
     if not label or not text:
         return False
     escaped_label = re.escape(label)
-    direct_pattern = re.compile(rf"\b{escaped_label}\b\s+(?:{_VERB_PATTERN})\b", re.IGNORECASE)
-    reverse_pattern = re.compile(rf"(?:{_VERB_PATTERN})\s+\b{escaped_label}\b", re.IGNORECASE)
+    direct_pattern = re.compile(
+        rf"\b{escaped_label}\b\s+(?:{_VERB_PATTERN})\b", re.IGNORECASE
+    )
+    reverse_pattern = re.compile(
+        rf"(?:{_VERB_PATTERN})\s+\b{escaped_label}\b", re.IGNORECASE
+    )
     colon_pattern = re.compile(rf"^\s*{escaped_label}\s*:\s*", re.IGNORECASE)
 
     if colon_pattern.search(text):
@@ -679,7 +726,7 @@ def _format_gender_hint(male_votes: int, female_votes: int) -> str:
 def _normalize_candidate_name(raw: str) -> Optional[str]:
     if not raw:
         return None
-    cleaned = raw.strip().strip('"“”\'’.,:;!')
+    cleaned = raw.strip().strip("\"“”'’.,:;!")
     cleaned = re.sub(r"\s+", " ", cleaned).strip()
     if not cleaned:
         return None
@@ -712,4 +759,4 @@ def _normalize_candidate_name(raw: str) -> Optional[str]:
     lowered = candidate.lower()
     if lowered in _PRONOUN_LABELS or lowered in _STOP_LABELS:
         return None
-    return candidate
\ No newline at end of file
+    return candidate
diff --git a/abogen/speaker_configs.py b/abogen/speaker_configs.py
index 283389e..04ab198 100644
--- a/abogen/speaker_configs.py
+++ b/abogen/speaker_configs.py
@@ -135,7 +135,11 @@ def _sanitize_speaker(entry: Dict[str, Any]) -> Dict[str, Any]:
             normalized_langs.append(code.lower())
     resolved_voice = entry.get("resolved_voice") or voice_formula or voice
     resolved_label = label or entry.get("id") or ""
-    slug = entry.get("id") if isinstance(entry.get("id"), str) else slugify_label(resolved_label)
+    slug = (
+        entry.get("id")
+        if isinstance(entry.get("id"), str)
+        else slugify_label(resolved_label)
+    )
     return {
         "id": slug,
         "label": resolved_label,
diff --git a/abogen/subtitle_utils.py b/abogen/subtitle_utils.py
index 73576c0..5455c55 100644
--- a/abogen/subtitle_utils.py
+++ b/abogen/subtitle_utils.py
@@ -37,6 +37,7 @@ def clean_subtitle_text(text):
     text = _CHAPTER_MARKER_PATTERN.sub("", text)
     return text.strip()
 
+
 def calculate_text_length(text):
     # Use pre-compiled patterns for better performance
     # Ignore chapter markers and metadata patterns in a single pass
@@ -48,6 +49,7 @@ def calculate_text_length(text):
     char_count = len(text)
     return char_count
 
+
 def clean_text(text, *args, **kwargs):
     # Remove metadata tags first
     text = _METADATA_TAG_PATTERN.sub("", text)
diff --git a/abogen/text_extractor.py b/abogen/text_extractor.py
index b6e2ee9..7d6bcf3 100644
--- a/abogen/text_extractor.py
+++ b/abogen/text_extractor.py
@@ -110,13 +110,19 @@ def _extract_from_string(raw: str, default_title: str) -> ExtractionResult:
     normalized_tags = _normalize_metadata_keys(raw_metadata)
     chapter_count = len(chapters)
     artist_value = normalized_tags.get("artist")
-    authors = [name.strip() for name in artist_value.split(",") if name.strip()] if artist_value else []
+    authors = (
+        [name.strip() for name in artist_value.split(",") if name.strip()]
+        if artist_value
+        else []
+    )
     metadata_source = MetadataSource(
         title=normalized_tags.get("title") or default_title,
         authors=authors,
         publication_year=normalized_tags.get("year"),
     )
-    metadata = _build_metadata_payload(metadata_source, chapter_count, "text", default_title)
+    metadata = _build_metadata_payload(
+        metadata_source, chapter_count, "text", default_title
+    )
     metadata.update(normalized_tags)
     if not chapters:
         chapters = [ExtractedChapter(title=default_title, text="")]
@@ -148,9 +154,11 @@ def _split_chapters(content: str, default_title: str) -> List[ExtractedChapter]:
     current_title = default_title
 
     for match in matches:
-        segment = content[last_index:match.start()]
+        segment = content[last_index : match.start()]
         if segment.strip():
-            chapters.append(ExtractedChapter(title=current_title, text=clean_text(segment)))
+            chapters.append(
+                ExtractedChapter(title=current_title, text=clean_text(segment))
+            )
         current_title = match.group(1).strip() or default_title
         last_index = match.end()
 
@@ -271,19 +279,27 @@ def _extract_markdown(path: Path) -> ExtractionResult:
     raw = path.read_text(encoding=encoding, errors="replace")
     metadata_source, chapters = _parse_markdown(raw, path.stem)
     if not chapters:
-        chapters = [ExtractedChapter(title=metadata_source.title or path.stem, text=clean_text(raw))]
-    metadata = _build_metadata_payload(metadata_source, len(chapters), "markdown", path.stem)
+        chapters = [
+            ExtractedChapter(
+                title=metadata_source.title or path.stem, text=clean_text(raw)
+            )
+        ]
+    metadata = _build_metadata_payload(
+        metadata_source, len(chapters), "markdown", path.stem
+    )
     return ExtractionResult(chapters=chapters, metadata=metadata)
 
 
-def _parse_markdown(raw: str, default_title: str) -> Tuple[MetadataSource, List[ExtractedChapter]]:
+def _parse_markdown(
+    raw: str, default_title: str
+) -> Tuple[MetadataSource, List[ExtractedChapter]]:
     metadata = MetadataSource()
     text = textwrap.dedent(raw)
     frontmatter_match = re.match(r"^---\s*\n(.*?)\n---\s*\n", text, re.DOTALL)
     if frontmatter_match:
         frontmatter = frontmatter_match.group(1)
         _parse_markdown_frontmatter(frontmatter, metadata)
-        text_body = text[frontmatter_match.end():]
+        text_body = text[frontmatter_match.end() :]
     else:
         text_body = text
 
@@ -324,7 +340,11 @@ def _parse_markdown(raw: str, default_title: str) -> Tuple[MetadataSource, List[
 
     chapters: List[ExtractedChapter] = []
     for index, (header_id, start, name) in enumerate(header_positions):
-        end = header_positions[index + 1][1] if index + 1 < len(header_positions) else len(html)
+        end = (
+            header_positions[index + 1][1]
+            if index + 1 < len(header_positions)
+            else len(html)
+        )
         section_html = html[start:end]
         section_soup = BeautifulSoup(section_html, "html.parser")
         header_tag = section_soup.find(attrs={"id": header_id})
@@ -336,7 +356,14 @@ def _parse_markdown(raw: str, default_title: str) -> Tuple[MetadataSource, List[
         chapters.append(ExtractedChapter(title=name.strip(), text=section_text))
 
     if not metadata.title:
-        first_h1 = next((header for header in headers if header.get("level") == 1 and header.get("name")), None)
+        first_h1 = next(
+            (
+                header
+                for header in headers
+                if header.get("level") == 1 and header.get("name")
+            ),
+            None,
+        )
         if first_h1:
             metadata.title = str(first_h1["name"])
 
@@ -344,21 +371,27 @@ def _parse_markdown(raw: str, default_title: str) -> Tuple[MetadataSource, List[
 
 
 def _parse_markdown_frontmatter(frontmatter: str, metadata: MetadataSource) -> None:
-    title_match = re.search(r"^title:\s*(.+)$", frontmatter, re.MULTILINE | re.IGNORECASE)
+    title_match = re.search(
+        r"^title:\s*(.+)$", frontmatter, re.MULTILINE | re.IGNORECASE
+    )
     if title_match:
-        metadata.title = title_match.group(1).strip().strip('"\'')
+        metadata.title = title_match.group(1).strip().strip("\"'")
 
-    author_match = re.search(r"^author:\s*(.+)$", frontmatter, re.MULTILINE | re.IGNORECASE)
+    author_match = re.search(
+        r"^author:\s*(.+)$", frontmatter, re.MULTILINE | re.IGNORECASE
+    )
     if author_match:
-        metadata.authors = [author_match.group(1).strip().strip('"\'')]
+        metadata.authors = [author_match.group(1).strip().strip("\"'")]
 
-    desc_match = re.search(r"^description:\s*(.+)$", frontmatter, re.MULTILINE | re.IGNORECASE)
+    desc_match = re.search(
+        r"^description:\s*(.+)$", frontmatter, re.MULTILINE | re.IGNORECASE
+    )
     if desc_match:
-        metadata.description = desc_match.group(1).strip().strip('"\'')
+        metadata.description = desc_match.group(1).strip().strip("\"'")
 
     date_match = re.search(r"^date:\s*(.+)$", frontmatter, re.MULTILINE | re.IGNORECASE)
     if date_match:
-        date_str = date_match.group(1).strip().strip('\"\'')
+        date_str = date_match.group(1).strip().strip("\"'")
         year_match = re.search(r"\b(19|20)\d{2}\b", date_str)
         if year_match:
             metadata.publication_year = year_match.group(0)
@@ -390,7 +423,9 @@ class EpubExtractor:
             chapters = self._process_spine_fallback()
         if not chapters:
             chapters = [ExtractedChapter(title=self.path.stem, text="")]
-        metadata = _build_metadata_payload(metadata_source, len(chapters), "epub", self.path.stem)
+        metadata = _build_metadata_payload(
+            metadata_source, len(chapters), "epub", self.path.stem
+        )
         metadata.setdefault("chapter_count", str(len(chapters)))
         if metadata_source.series:
             series_text = str(metadata_source.series).strip()
@@ -424,7 +459,9 @@ class EpubExtractor:
         try:
             author_items = self.book.get_metadata("DC", "creator")
             if author_items:
-                metadata.authors = [author[0] for author in author_items if author and author[0]]
+                metadata.authors = [
+                    author[0] for author in author_items if author and author[0]
+                ]
         except Exception as exc:
             logger.debug("Failed to extract EPUB author metadata: %s", exc)
 
@@ -447,7 +484,9 @@ class EpubExtractor:
             if date_items:
                 date_str = date_items[0][0]
                 year_match = re.search(r"\b(19|20)\d{2}\b", date_str)
-                metadata.publication_year = year_match.group(0) if year_match else date_str
+                metadata.publication_year = (
+                    year_match.group(0) if year_match else date_str
+                )
         except Exception as exc:
             logger.debug("Failed to extract EPUB publication year metadata: %s", exc)
 
@@ -482,7 +521,16 @@ class EpubExtractor:
             if name in {"calibre:series", "series"} and series_name is None:
                 series_name = candidate_text
                 continue
-            if name in {"calibre:series_index", "calibre:seriesindex", "series_index", "seriesindex"} and series_index is None:
+            if (
+                name
+                in {
+                    "calibre:series_index",
+                    "calibre:seriesindex",
+                    "series_index",
+                    "seriesindex",
+                }
+                and series_index is None
+            ):
                 series_index = candidate_text
                 continue
 
@@ -533,7 +581,9 @@ class EpubExtractor:
 
         self.spine_docs = self._build_spine_docs()
         doc_order = {href: index for index, href in enumerate(self.spine_docs)}
-        doc_order_decoded = {urllib.parse.unquote(href): index for href, index in doc_order.items()}
+        doc_order_decoded = {
+            urllib.parse.unquote(href): index for href, index in doc_order.items()
+        }
 
         nav_targets = self._collect_nav_targets(nav_soup, nav_type)
         self._cache_relevant_documents(doc_order, nav_targets)
@@ -544,7 +594,9 @@ class EpubExtractor:
             if not nav_map:
                 raise ValueError("NCX navigation missing <navMap>")
             for nav_point in nav_map.find_all("navPoint", recursive=False):
-                self._parse_ncx_navpoint(nav_point, ordered_entries, doc_order, doc_order_decoded)
+                self._parse_ncx_navpoint(
+                    nav_point, ordered_entries, doc_order, doc_order_decoded
+                )
         else:
             toc_nav = nav_soup.find("nav", attrs={"epub:type": "toc"})
             if toc_nav is None:
@@ -558,7 +610,9 @@ class EpubExtractor:
             if top_ol is None:
                 raise ValueError("TOC navigation missing <ol>")
             for li in top_ol.find_all("li", recursive=False):
-                self._parse_html_nav_li(li, ordered_entries, doc_order, doc_order_decoded)
+                self._parse_html_nav_li(
+                    li, ordered_entries, doc_order, doc_order_decoded
+                )
 
         if not ordered_entries:
             raise ValueError("No navigation entries found")
@@ -591,7 +645,9 @@ class EpubExtractor:
             text = self._html_to_text(html_content)
             if not text:
                 continue
-            title = self._resolve_document_title(html_content, fallback=f"Untitled Chapter {index + 1}")
+            title = self._resolve_document_title(
+                html_content, fallback=f"Untitled Chapter {index + 1}"
+            )
             chapters.append(ExtractedChapter(title=title, text=text))
         return chapters
 
@@ -605,7 +661,8 @@ class EpubExtractor:
                 (
                     item
                     for item in nav_items
-                    if "nav" in item.get_name().lower() and item.get_name().lower().endswith((".xhtml", ".html"))
+                    if "nav" in item.get_name().lower()
+                    and item.get_name().lower().endswith((".xhtml", ".html"))
                 ),
                 None,
             )
@@ -627,7 +684,11 @@ class EpubExtractor:
 
         if not nav_item and nav_items:
             ncx_candidate = next(
-                (item for item in nav_items if item.get_name().lower().endswith(".ncx")),
+                (
+                    item
+                    for item in nav_items
+                    if item.get_name().lower().endswith(".ncx")
+                ),
                 None,
             )
             if ncx_candidate:
@@ -682,7 +743,9 @@ class EpubExtractor:
                     targets.append(href_value.split("#", 1)[0])
         return targets
 
-    def _cache_relevant_documents(self, doc_order: Dict[str, int], nav_targets: List[str]) -> None:
+    def _cache_relevant_documents(
+        self, doc_order: Dict[str, int], nav_targets: List[str]
+    ) -> None:
         needed: set[str] = set(doc_order.keys())
         for target in nav_targets:
             needed.add(target)
@@ -718,7 +781,9 @@ class EpubExtractor:
 
         if src:
             base_href, fragment = src.split("#", 1) if "#" in src else (src, None)
-            doc_key, doc_idx = self._find_doc_key(base_href, doc_order, doc_order_decoded)
+            doc_key, doc_idx = self._find_doc_key(
+                base_href, doc_order, doc_order_decoded
+            )
             if doc_key is not None and doc_idx is not None:
                 position = self._find_position_robust(doc_key, fragment)
                 ordered_entries.append(
@@ -738,7 +803,9 @@ class EpubExtractor:
                 )
 
         for child_navpoint in nav_point.find_all("navPoint", recursive=False):
-            self._parse_ncx_navpoint(child_navpoint, ordered_entries, doc_order, doc_order_decoded)
+            self._parse_ncx_navpoint(
+                child_navpoint, ordered_entries, doc_order, doc_order_decoded
+            )
 
     def _parse_html_nav_li(
         self,
@@ -767,7 +834,9 @@ class EpubExtractor:
 
         if src:
             base_href, fragment = src.split("#", 1) if "#" in src else (src, None)
-            doc_key, doc_idx = self._find_doc_key(base_href, doc_order, doc_order_decoded)
+            doc_key, doc_idx = self._find_doc_key(
+                base_href, doc_order, doc_order_decoded
+            )
             if doc_key is not None and doc_idx is not None:
                 position = self._find_position_robust(doc_key, fragment)
                 ordered_entries.append(
@@ -788,7 +857,9 @@ class EpubExtractor:
 
         for child_ol in li_element.find_all("ol", recursive=False):
             for child_li in child_ol.find_all("li", recursive=False):
-                self._parse_html_nav_li(child_li, ordered_entries, doc_order, doc_order_decoded)
+                self._parse_html_nav_li(
+                    child_li, ordered_entries, doc_order, doc_order_decoded
+                )
 
     def _find_doc_key(
         self,
@@ -825,7 +896,9 @@ class EpubExtractor:
                 if pos != -1:
                     return pos
         except Exception:
-            logger.debug("BeautifulSoup failed to locate id '%s' in %s", fragment_id, doc_href)
+            logger.debug(
+                "BeautifulSoup failed to locate id '%s' in %s", fragment_id, doc_href
+            )
 
         safe_fragment_id = re.escape(fragment_id)
         id_name_pattern = re.compile(
@@ -844,13 +917,17 @@ class EpubExtractor:
             tag_start = html_content.rfind("<", 0, pos)
             return tag_start if tag_start != -1 else pos
 
-        logger.warning("Anchor '%s' not found in %s. Defaulting to start.", fragment_id, doc_href)
+        logger.warning(
+            "Anchor '%s' not found in %s. Defaulting to start.", fragment_id, doc_href
+        )
         return 0
 
     def _slice_entries(self, ordered_entries: List[NavEntry]) -> List[ExtractedChapter]:
         chapters: List[ExtractedChapter] = []
         for index, entry in enumerate(ordered_entries):
-            next_entry = ordered_entries[index + 1] if index + 1 < len(ordered_entries) else None
+            next_entry = (
+                ordered_entries[index + 1] if index + 1 < len(ordered_entries) else None
+            )
             slice_html = self._slice_entry(entry, next_entry)
             text = self._html_to_text(slice_html)
             if not text:
diff --git a/abogen/tts_supertonic.py b/abogen/tts_supertonic.py
index 68b7e69..ed37c81 100644
--- a/abogen/tts_supertonic.py
+++ b/abogen/tts_supertonic.py
@@ -47,7 +47,9 @@ def _resample_linear(audio: np.ndarray, src_rate: int, dst_rate: int) -> np.ndar
     return np.interp(x_new, x_old, audio).astype("float32", copy=False)
 
 
-def _split_text(text: str, *, split_pattern: Optional[str], max_chunk_length: int) -> list[str]:
+def _split_text(
+    text: str, *, split_pattern: Optional[str], max_chunk_length: int
+) -> list[str]:
     stripped = (text or "").strip()
     if not stripped:
         return []
@@ -81,13 +83,17 @@ def _split_text(text: str, *, split_pattern: Optional[str], max_chunk_length: in
     return result
 
 
-_UNSUPPORTED_CHARS_RE = re.compile(r"unsupported character\(s\):\s*(\[[^\]]*\])", re.IGNORECASE)
+_UNSUPPORTED_CHARS_RE = re.compile(
+    r"unsupported character\(s\):\s*(\[[^\]]*\])", re.IGNORECASE
+)
 
 
 def _parse_unsupported_characters(error: BaseException) -> list[str]:
     """Best-effort extraction of unsupported characters from SuperTonic errors."""
 
-    message = " ".join(str(part) for part in getattr(error, "args", ()) if part is not None) or str(error)
+    message = " ".join(
+        str(part) for part in getattr(error, "args", ()) if part is not None
+    ) or str(error)
     match = _UNSUPPORTED_CHARS_RE.search(message)
     if not match:
         return []
@@ -127,8 +133,9 @@ def _configure_supertonic_gpu() -> None:
     """Patch supertonic's config to enable GPU acceleration if available."""
     try:
         import onnxruntime as ort
+
         available = ort.get_available_providers()
-        
+
         # Use CUDA if available, skip TensorRT (requires extra libs not always present)
         # TensorrtExecutionProvider may be listed as available but fail at runtime
         # if TensorRT libraries (libnvinfer.so) are not installed
@@ -136,11 +143,12 @@ def _configure_supertonic_gpu() -> None:
         if "CUDAExecutionProvider" in available:
             providers.append("CUDAExecutionProvider")
         providers.append("CPUExecutionProvider")
-        
+
         # Patch supertonic's config and loader before TTS import
         # We must patch both because loader imports the value at module load time
         import supertonic.config as supertonic_config
         import supertonic.loader as supertonic_loader
+
         supertonic_config.DEFAULT_ONNX_PROVIDERS = providers
         supertonic_loader.DEFAULT_ONNX_PROVIDERS = providers
         logger.info("Supertonic ONNX providers configured: %s", providers)
@@ -191,7 +199,9 @@ class SupertonicPipeline:
         speed_value = max(0.7, min(2.0, speed_value))
 
         style = self._tts.get_voice_style(voice_name=voice_name)
-        chunks = _split_text(text, split_pattern=split_pattern, max_chunk_length=self.max_chunk_length)
+        chunks = _split_text(
+            text, split_pattern=split_pattern, max_chunk_length=self.max_chunk_length
+        )
         for chunk in chunks:
             chunk_to_speak = chunk
             removed: set[str] = set()
@@ -217,7 +227,9 @@ class SupertonicPipeline:
                         raise
 
                     removed.update(unsupported)
-                    sanitized = _remove_unsupported_characters(chunk_to_speak, unsupported).strip()
+                    sanitized = _remove_unsupported_characters(
+                        chunk_to_speak, unsupported
+                    ).strip()
 
                     # If we didn't change anything, don't loop forever.
                     if sanitized == chunk_to_speak.strip():
diff --git a/abogen/utils.py b/abogen/utils.py
index e984157..156e9f8 100644
--- a/abogen/utils.py
+++ b/abogen/utils.py
@@ -14,6 +14,7 @@ from functools import lru_cache
 
 from dotenv import load_dotenv, find_dotenv
 
+
 def _load_environment() -> None:
     explicit_path = os.environ.get("ABOGEN_ENV_FILE")
     if explicit_path:
@@ -56,6 +57,7 @@ def detect_encoding(file_path):
     encoding = detected_encoding if detected_encoding else "utf-8"
     return encoding.lower()
 
+
 def get_resource_path(package, resource):
     """
     Get the path to a resource file, with fallback to local file system.
@@ -146,7 +148,9 @@ def get_user_settings_dir():
         if os.path.exists(legacy_dir):
             return ensure_directory(legacy_dir)
 
-    config_dir = user_config_dir("abogen", appauthor=False, roaming=True, ensure_exists=True)
+    config_dir = user_config_dir(
+        "abogen", appauthor=False, roaming=True, ensure_exists=True
+    )
     return ensure_directory(config_dir)
 
 
@@ -250,7 +254,9 @@ def get_user_cache_root():
 
 
 def get_internal_cache_root():
-    root = os.environ.get("ABOGEN_INTERNAL_CACHE_ROOT") or os.environ.get("XDG_CACHE_HOME")
+    root = os.environ.get("ABOGEN_INTERNAL_CACHE_ROOT") or os.environ.get(
+        "XDG_CACHE_HOME"
+    )
     if root:
         return ensure_directory(root)
     home_dir = os.environ.get("HOME") or os.path.join("/tmp", "abogen-home")
@@ -274,9 +280,8 @@ def get_user_cache_path(folder=None):
 
 @lru_cache(maxsize=1)
 def get_user_output_root():
-    override = (
-        os.environ.get("ABOGEN_OUTPUT_DIR")
-        or os.environ.get("ABOGEN_OUTPUT_ROOT")
+    override = os.environ.get("ABOGEN_OUTPUT_DIR") or os.environ.get(
+        "ABOGEN_OUTPUT_ROOT"
     )
     if override:
         return ensure_directory(override)
@@ -290,7 +295,10 @@ def get_user_output_path(folder=None):
     return base
 
 
-_sleep_procs: Dict[str, Optional[subprocess.Popen[str]]] = {"Darwin": None, "Linux": None}  # Store sleep prevention processes
+_sleep_procs: Dict[str, Optional[subprocess.Popen[str]]] = {
+    "Darwin": None,
+    "Linux": None,
+}  # Store sleep prevention processes
 
 
 def clean_text(text, *args, **kwargs):
@@ -328,7 +336,9 @@ def create_process(cmd, stdin=None, text=True, capture_output=False):
     # Determine shell usage: use shell only for string commands
     use_shell = isinstance(cmd, str)
     if use_shell:
-        logger.warning("Security Warning: create_process called with string command. Prefer using a list of arguments to avoid shell injection risks.")
+        logger.warning(
+            "Security Warning: create_process called with string command. Prefer using a list of arguments to avoid shell injection risks."
+        )
 
     kwargs = {
         "shell": use_shell,
@@ -439,18 +449,18 @@ def get_gpu_acceleration(enabled):
 
         if not enabled:
             return "GPU available but using CPU.", False
-        
+
         # Check for Apple Silicon MPS
         if platform.system() == "Darwin" and platform.processor() == "arm":
             if torch.backends.mps.is_available():
                 return "MPS GPU available and enabled.", True
             else:
                 return "MPS GPU not available on Apple Silicon. Using CPU.", False
-        
+
         # Check for CUDA
         if cuda_available():
             return "CUDA GPU available and enabled.", True
-        
+
         # Gather CUDA diagnostic info if not available
         try:
             cuda_devices = torch.cuda.device_count()
diff --git a/abogen/voice_cache.py b/abogen/voice_cache.py
index df1662f..fd8e4df 100644
--- a/abogen/voice_cache.py
+++ b/abogen/voice_cache.py
@@ -12,9 +12,11 @@ except Exception:  # pragma: no cover - import fallback
     LocalEntryNotFoundError = None  # type: ignore[assignment]
 
 if LocalEntryNotFoundError is None:  # pragma: no cover - fallback for tests
+
     class LocalEntryNotFoundError(Exception):
         pass
 
+
 from abogen.constants import VOICES_INTERNAL
 
 _CACHE_LOCK = threading.Lock()
@@ -140,4 +142,4 @@ def _ensure_single_voice_asset(
         pass
 
     hf_hub_download(resume_download=True, **common_kwargs)
-    return True
\ No newline at end of file
+    return True
diff --git a/abogen/voice_profiles.py b/abogen/voice_profiles.py
index dede121..608b943 100644
--- a/abogen/voice_profiles.py
+++ b/abogen/voice_profiles.py
@@ -110,9 +110,17 @@ def normalize_profile_entry(entry: Any) -> Dict[str, Any]:
         return {
             "provider": "supertonic",
             "language": language,
-            "voice": _normalize_supertonic_voice(entry.get("voice") or entry.get("voice_name") or entry.get("name")),
-            "total_steps": _coerce_supertonic_steps(entry.get("total_steps") or entry.get("supertonic_total_steps") or entry.get("quality")),
-            "speed": _coerce_supertonic_speed(entry.get("speed") or entry.get("supertonic_speed")),
+            "voice": _normalize_supertonic_voice(
+                entry.get("voice") or entry.get("voice_name") or entry.get("name")
+            ),
+            "total_steps": _coerce_supertonic_steps(
+                entry.get("total_steps")
+                or entry.get("supertonic_total_steps")
+                or entry.get("quality")
+            ),
+            "speed": _coerce_supertonic_speed(
+                entry.get("speed") or entry.get("supertonic_speed")
+            ),
         }
 
     voices = _normalize_voice_entries(entry.get("voices", []))
diff --git a/build_pypi.py b/build_pypi.py
index 076e538..9203498 100644
--- a/build_pypi.py
+++ b/build_pypi.py
@@ -27,10 +27,11 @@ def main():
             version = None
     if version:
         print(f"🔖 Package version: {version}")
-    
+
     # Check if build module is installed, install if not
     # Temporarily remove script_dir from sys.path to avoid importing local build.py
     import sys
+
     original_path = sys.path[:]
     try:
         sys.path = [p for p in sys.path if os.path.abspath(p) != script_dir]
diff --git a/tests/__init__.py b/tests/__init__.py
index c6c023a..1b2f809 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -10,7 +10,9 @@ import sys
 from types import ModuleType
 
 
-def _soundfile_write_stub(file_obj, data, samplerate, format="WAV", **_kwargs):  # pragma: no cover - stub
+def _soundfile_write_stub(
+    file_obj, data, samplerate, format="WAV", **_kwargs
+):  # pragma: no cover - stub
     """Minimal stand-in for soundfile.write used in tests.
 
     The real library streams waveform data to disk. Our tests don't exercise
diff --git a/tests/test_audiobookshelf_client.py b/tests/test_audiobookshelf_client.py
index 1491829..12678e4 100644
--- a/tests/test_audiobookshelf_client.py
+++ b/tests/test_audiobookshelf_client.py
@@ -2,7 +2,10 @@ from __future__ import annotations
 
 import json
 
-from abogen.integrations.audiobookshelf import AudiobookshelfClient, AudiobookshelfConfig
+from abogen.integrations.audiobookshelf import (
+    AudiobookshelfClient,
+    AudiobookshelfConfig,
+)
 
 
 def test_upload_fields_include_series_sequence(tmp_path):
diff --git a/tests/test_book_handler_regression.py b/tests/test_book_handler_regression.py
index e8420e5..a2fd87d 100644
--- a/tests/test_book_handler_regression.py
+++ b/tests/test_book_handler_regression.py
@@ -6,7 +6,7 @@ import time
 from PyQt6.QtWidgets import QApplication
 
 # Ensure we can import the module
-sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
 from abogen.book_handler import HandlerDialog
 from ebooklib import epub
@@ -14,6 +14,7 @@ from ebooklib import epub
 # We need a QApplication instance for QWriter/QDialog
 app = QApplication(sys.argv)
 
+
 class TestBookHandlerRegression(unittest.TestCase):
 
     def setUp(self):
@@ -48,26 +49,29 @@ class TestBookHandlerRegression(unittest.TestCase):
         # HandlerDialog starts processing in a background thread in __init__
         # We assume headless environment, so we won't show it.
         # But we need to wait for the thread to finish.
-        
+
         dialog = HandlerDialog(self.sample_epub_path)
-        
+
         # Wait for thread to finish
         # The dialog emits no signal publicly, but we can check internal state or thread
-        
+
         start_time = time.time()
         while time.time() - start_time < 5:
             # HandlerDialog logic:
             # _loader_thread.finished connect to _on_load_finished
             # _on_load_finished populates content_texts and content_lengths
-            
+
             # We can check if content_texts is populated
             if dialog.content_texts:
                 break
-            app.processEvents() # Process Qt events to let thread signals propagate
+            app.processEvents()  # Process Qt events to let thread signals propagate
             time.sleep(0.1)
-            
-        self.assertTrue(len(dialog.content_texts) > 0, "HandlerDialog failed to process content in time")
-        
+
+        self.assertTrue(
+            len(dialog.content_texts) > 0,
+            "HandlerDialog failed to process content in time",
+        )
+
         # Validate content similar to what we expect
         # intro.xhtml should be there
         found_intro = False
@@ -80,5 +84,6 @@ class TestBookHandlerRegression(unittest.TestCase):
         # Cleanup
         dialog.close()
 
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/test_book_parser.py b/tests/test_book_parser.py
index e8172ea..cff9d44 100644
--- a/tests/test_book_parser.py
+++ b/tests/test_book_parser.py
@@ -6,10 +6,11 @@ import fitz  # PyMuPDF
 from ebooklib import epub
 
 # Ensure we can import the module
-sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
 from abogen.book_parser import get_book_parser, PdfParser, EpubParser, MarkdownParser
 
+
 class TestBookParser(unittest.TestCase):
 
     def setUp(self):
@@ -32,18 +33,18 @@ class TestBookParser(unittest.TestCase):
 
     def _create_sample_pdf(self):
         doc = fitz.open()
-        
+
         # Page 1
         page1 = doc.new_page()
         page1.insert_text((50, 50), "Page 1 content")
         # Add pattern to be cleaned
-        page1.insert_text((50, 100), "[12]") 
-        page1.insert_text((50, 200), "1") # Page number at bottom
-        
+        page1.insert_text((50, 100), "[12]")
+        page1.insert_text((50, 200), "1")  # Page number at bottom
+
         # Page 2
         page2 = doc.new_page()
         page2.insert_text((50, 50), "Page 2 content")
-        
+
         doc.save(self.sample_pdf_path)
         doc.close()
 
@@ -65,7 +66,7 @@ class TestBookParser(unittest.TestCase):
 
         # Basic spine and nav
         book.spine = ["nav", c1, c2]
-        
+
         # Add NCX and NAV for compatibility
         book.add_item(epub.EpubNcx())
         book.add_item(epub.EpubNav())
@@ -93,11 +94,11 @@ class TestBookParser(unittest.TestCase):
         # 1. Copy sample epub to something.pdf
         wrong_ext_path = os.path.join(self.test_dir, "actually_epub.pdf")
         shutil.copy(self.sample_epub_path, wrong_ext_path)
-        
+
         # 2. Open it telling parser it IS epub
         parser = get_book_parser(wrong_ext_path, file_type="epub")
         self.assertIsInstance(parser, EpubParser)
-        
+
         # Should load successfully
         parser.load()
         self.assertTrue(parser.book is not None)
@@ -109,7 +110,7 @@ class TestBookParser(unittest.TestCase):
 
         self.assertIn("page_1", parser.content_texts)
         self.assertIn("page_2", parser.content_texts)
-        
+
         text1 = parser.content_texts["page_1"]
         self.assertIn("Page 1 content", text1)
         self.assertNotIn("[12]", text1)
@@ -118,7 +119,7 @@ class TestBookParser(unittest.TestCase):
         """Test MarkdownParser splitting logic."""
         parser = get_book_parser(self.sample_md_path)
         parser.process_content()
-        
+
         # Should have Chapter 1 and Chapter 2 keys (actual keys depend on ID generation)
         # Markdown extensions might slugify IDs: "chapter-1"
         self.assertIn("chapter-1", parser.content_texts)
@@ -130,7 +131,7 @@ class TestBookParser(unittest.TestCase):
         """Test EpubParser processing."""
         parser = get_book_parser(self.sample_epub_path)
         parser.process_content()
-        
+
         self.assertIn("intro.xhtml", parser.content_texts)
         self.assertIn("chap1.xhtml", parser.content_texts)
         self.assertIn("Welcome to the book", parser.content_texts["intro.xhtml"])
@@ -140,7 +141,7 @@ class TestBookParser(unittest.TestCase):
         parser = get_book_parser(self.sample_epub_path)
         # Processing content triggers metadata extraction in current implementation
         parser.process_content()
-        
+
         metadata = parser.get_metadata()
         self.assertEqual(metadata.get("title"), "Sample Book")
         self.assertEqual(metadata.get("author"), "Test Author")
@@ -149,23 +150,23 @@ class TestBookParser(unittest.TestCase):
         """Test <ol> handling in EpubParser."""
         parser = get_book_parser(self.sample_epub_path)
         parser.process_content()
-        
+
         text = parser.content_texts.get("chap1.xhtml", "")
         self.assertIn("1) Item One", text)
         self.assertIn("2) Item Two", text)
 
     def test_find_position_robust_logic(self):
         """Unit test for _find_position_robust on EpubParser."""
-        parser = EpubParser(self.sample_epub_path) # Instantiate directly
-        
+        parser = EpubParser(self.sample_epub_path)  # Instantiate directly
+
         html = '<html><body><p>Start</p><h1 id="target">Heading</h1><p>End</p></body></html>'
         parser.doc_content["dummy.html"] = html
-        
+
         # Test finding ID
         pos = parser._find_position_robust("dummy.html", "target")
         self.assertGreater(pos, 0)
         self.assertTrue(html[pos:].startswith('<h1 id="target"'))
-        
+
         # Test missing ID
         pos_missing = parser._find_position_robust("dummy.html", "missing")
         self.assertEqual(pos_missing, 0)
@@ -177,7 +178,7 @@ class TestBookParser(unittest.TestCase):
         chapters = parser_pdf.get_chapters()
         self.assertEqual(len(chapters), 2)
         self.assertEqual(chapters[0], ("page_1", "Page 1"))
-        
+
         # MD
         parser_md = get_book_parser(self.sample_md_path)
         parser_md.process_content()  # Must process to get structure
@@ -191,7 +192,7 @@ class TestBookParser(unittest.TestCase):
         parser = get_book_parser(self.sample_md_path)
         parser.process_content()
         text = parser.get_formatted_text()
-        
+
         self.assertIn("<<CHAPTER_MARKER:Chapter 1>>", text)
         self.assertIn("Some text", text)
 
@@ -206,5 +207,6 @@ class TestBookParser(unittest.TestCase):
         md_parser = MarkdownParser(self.sample_md_path)
         self.assertEqual(md_parser.file_type, "markdown")
 
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/test_calibre_opds.py b/tests/test_calibre_opds.py
index 82f6bf4..e19bf07 100644
--- a/tests/test_calibre_opds.py
+++ b/tests/test_calibre_opds.py
@@ -1,4 +1,10 @@
-from abogen.integrations.calibre_opds import CalibreOPDSClient, OPDSEntry, OPDSFeed, OPDSLink, feed_to_dict
+from abogen.integrations.calibre_opds import (
+    CalibreOPDSClient,
+    OPDSEntry,
+    OPDSFeed,
+    OPDSLink,
+    feed_to_dict,
+)
 
 
 def test_calibre_opds_feed_exposes_series_metadata() -> None:
@@ -158,25 +164,33 @@ This is the detailed summary text.</summary>
 
 
 def test_calibre_opds_relative_urls_keep_catalog_prefix() -> None:
-  client = CalibreOPDSClient("http://example.com/opds/")
+    client = CalibreOPDSClient("http://example.com/opds/")
 
-  assert client._make_url("search") == "http://example.com/opds/search"
-  assert client._make_url("books/sample.epub") == "http://example.com/opds/books/sample.epub"
-  assert client._make_url("/cover/1") == "http://example.com/cover/1"
-  assert client._make_url("?page=2") == "http://example.com/opds?page=2"
+    assert client._make_url("search") == "http://example.com/opds/search"
+    assert (
+        client._make_url("books/sample.epub")
+        == "http://example.com/opds/books/sample.epub"
+    )
+    assert client._make_url("/cover/1") == "http://example.com/cover/1"
+    assert client._make_url("?page=2") == "http://example.com/opds?page=2"
 
 
 def test_calibre_opds_base_url_without_trailing_slash() -> None:
-  """Ensure the client works with base URLs that don't have trailing slashes."""
-  client = CalibreOPDSClient("http://example.com/api/v1/opds")
+    """Ensure the client works with base URLs that don't have trailing slashes."""
+    client = CalibreOPDSClient("http://example.com/api/v1/opds")
 
-  # Base URL should be stored without trailing slash
-  assert client._base_url == "http://example.com/api/v1/opds"
-  # Relative paths should resolve as siblings to the base URL
-  assert client._make_url("catalog") == "http://example.com/api/v1/opds/catalog"
-  assert client._make_url("search?q=test") == "http://example.com/api/v1/opds/search?q=test"
-  assert client._make_url("/api/v1/opds/books") == "http://example.com/api/v1/opds/books"
-  assert client._make_url("?page=2") == "http://example.com/api/v1/opds?page=2"
+    # Base URL should be stored without trailing slash
+    assert client._base_url == "http://example.com/api/v1/opds"
+    # Relative paths should resolve as siblings to the base URL
+    assert client._make_url("catalog") == "http://example.com/api/v1/opds/catalog"
+    assert (
+        client._make_url("search?q=test")
+        == "http://example.com/api/v1/opds/search?q=test"
+    )
+    assert (
+        client._make_url("/api/v1/opds/books") == "http://example.com/api/v1/opds/books"
+    )
+    assert client._make_url("?page=2") == "http://example.com/api/v1/opds?page=2"
 
 
 def test_calibre_opds_filters_out_unsupported_formats() -> None:
@@ -253,365 +267,382 @@ def test_calibre_opds_navigation_entries_without_download_are_preserved() -> Non
 
 
 def test_calibre_opds_search_filters_by_title_and_author() -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  feed = OPDSFeed(
-    id="catalog",
-    title="Catalog",
-    entries=[
-      OPDSEntry(id="1", title="The Long Journey", authors=["Alice Smith"]),
-      OPDSEntry(id="2", title="Hidden Worlds", authors=["Bob Johnson"]),
-      OPDSEntry(id="3", title="Side Stories", authors=["Cara Nguyen"], series="Journey Tales"),
-    ],
-  )
+    client = CalibreOPDSClient("http://example.com/catalog")
+    feed = OPDSFeed(
+        id="catalog",
+        title="Catalog",
+        entries=[
+            OPDSEntry(id="1", title="The Long Journey", authors=["Alice Smith"]),
+            OPDSEntry(id="2", title="Hidden Worlds", authors=["Bob Johnson"]),
+            OPDSEntry(
+                id="3",
+                title="Side Stories",
+                authors=["Cara Nguyen"],
+                series="Journey Tales",
+            ),
+        ],
+    )
 
-  filtered = client._filter_feed_entries(feed, "journey alice")
-  assert [entry.id for entry in filtered.entries] == ["1"]
+    filtered = client._filter_feed_entries(feed, "journey alice")
+    assert [entry.id for entry in filtered.entries] == ["1"]
 
-  filtered = client._filter_feed_entries(feed, "bob")
-  assert [entry.id for entry in filtered.entries] == ["2"]
+    filtered = client._filter_feed_entries(feed, "bob")
+    assert [entry.id for entry in filtered.entries] == ["2"]
 
-  filtered = client._filter_feed_entries(feed, "journey tales")
-  assert [entry.id for entry in filtered.entries] == ["3"]
+    filtered = client._filter_feed_entries(feed, "journey tales")
+    assert [entry.id for entry in filtered.entries] == ["3"]
 
-  filtered = client._filter_feed_entries(feed, "missing")
-  assert filtered.entries == []
+    filtered = client._filter_feed_entries(feed, "missing")
+    assert filtered.entries == []
 
 
 def test_calibre_opds_local_search_follows_next(monkeypatch) -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  page_one = OPDSFeed(
-    id="catalog",
-    title="Catalog",
-    entries=[OPDSEntry(id="1", title="Unrelated", authors=["Alice Smith"])],
-    links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
-  )
-  page_two = OPDSFeed(
-    id="catalog",
-    title="Catalog",
-    entries=[OPDSEntry(id="2", title="The Journey Continues", authors=["Bob Johnson"])],
-    links={},
-  )
+    client = CalibreOPDSClient("http://example.com/catalog")
+    page_one = OPDSFeed(
+        id="catalog",
+        title="Catalog",
+        entries=[OPDSEntry(id="1", title="Unrelated", authors=["Alice Smith"])],
+        links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
+    )
+    page_two = OPDSFeed(
+        id="catalog",
+        title="Catalog",
+        entries=[
+            OPDSEntry(id="2", title="The Journey Continues", authors=["Bob Johnson"])
+        ],
+        links={},
+    )
 
-  def fake_fetch(href=None, params=None):
-    if href == "http://example.com/catalog?page=2":
-      return page_two
-    return page_one
+    def fake_fetch(href=None, params=None):
+        if href == "http://example.com/catalog?page=2":
+            return page_two
+        return page_one
 
-  monkeypatch.setattr(client, "fetch_feed", fake_fetch)
+    monkeypatch.setattr(client, "fetch_feed", fake_fetch)
 
-  result = client._local_search("journey", seed_feed=page_one)
-  assert [entry.id for entry in result.entries] == ["2"]
+    result = client._local_search("journey", seed_feed=page_one)
+    assert [entry.id for entry in result.entries] == ["2"]
 
 
 def test_calibre_opds_local_search_traverses_navigation(monkeypatch) -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  root_feed = OPDSFeed(
-    id="catalog",
-    title="Catalog",
-    entries=[
-      OPDSEntry(
-        id="nav-authors",
-        title="Browse Authors",
-        links=[
-          OPDSLink(
-            href="http://example.com/catalog/authors",
-            rel="http://opds-spec.org/navigation",
-            type="application/atom+xml;profile=opds-catalog",
-          )
+    client = CalibreOPDSClient("http://example.com/catalog")
+    root_feed = OPDSFeed(
+        id="catalog",
+        title="Catalog",
+        entries=[
+            OPDSEntry(
+                id="nav-authors",
+                title="Browse Authors",
+                links=[
+                    OPDSLink(
+                        href="http://example.com/catalog/authors",
+                        rel="http://opds-spec.org/navigation",
+                        type="application/atom+xml;profile=opds-catalog",
+                    )
+                ],
+            )
         ],
-      )
-    ],
-    links={},
-  )
-  authors_feed = OPDSFeed(
-    id="authors",
-    title="Authors",
-    entries=[
-      OPDSEntry(id="book-42", title="The Count of Monte Cristo", authors=["Alexandre Dumas"])
-    ],
-    links={},
-  )
+        links={},
+    )
+    authors_feed = OPDSFeed(
+        id="authors",
+        title="Authors",
+        entries=[
+            OPDSEntry(
+                id="book-42",
+                title="The Count of Monte Cristo",
+                authors=["Alexandre Dumas"],
+            )
+        ],
+        links={},
+    )
 
-  def fake_fetch(href=None, params=None):
-    if href == "http://example.com/catalog/authors":
-      return authors_feed
-    return root_feed
+    def fake_fetch(href=None, params=None):
+        if href == "http://example.com/catalog/authors":
+            return authors_feed
+        return root_feed
 
-  monkeypatch.setattr(client, "fetch_feed", fake_fetch)
+    monkeypatch.setattr(client, "fetch_feed", fake_fetch)
 
-  result = client._local_search("monte cristo", seed_feed=root_feed)
-  assert [entry.id for entry in result.entries] == ["book-42"]
+    result = client._local_search("monte cristo", seed_feed=root_feed)
+    assert [entry.id for entry in result.entries] == ["book-42"]
 
 
 def test_calibre_opds_search_falls_back_to_local_search(monkeypatch) -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  search_page = OPDSFeed(
-    id="catalog",
-    title="Catalog",
-    entries=[OPDSEntry(id="1", title="Unrelated", authors=["Alice Smith"])],
-    links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
-  )
-  next_page = OPDSFeed(
-    id="catalog",
-    title="Catalog",
-    entries=[OPDSEntry(id="2", title="Journey in Space", authors=["Cara Nguyen"])],
-    links={},
-  )
+    client = CalibreOPDSClient("http://example.com/catalog")
+    search_page = OPDSFeed(
+        id="catalog",
+        title="Catalog",
+        entries=[OPDSEntry(id="1", title="Unrelated", authors=["Alice Smith"])],
+        links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
+    )
+    next_page = OPDSFeed(
+        id="catalog",
+        title="Catalog",
+        entries=[OPDSEntry(id="2", title="Journey in Space", authors=["Cara Nguyen"])],
+        links={},
+    )
 
-  def fake_fetch(path=None, params=None):
-    if path == "search":
-      return search_page
-    if path == "http://example.com/catalog?page=2":
-      return next_page
-    return search_page
+    def fake_fetch(path=None, params=None):
+        if path == "search":
+            return search_page
+        if path == "http://example.com/catalog?page=2":
+            return next_page
+        return search_page
 
-  monkeypatch.setattr(client, "fetch_feed", fake_fetch)
+    monkeypatch.setattr(client, "fetch_feed", fake_fetch)
 
-  result = client.search("journey")
-  assert [entry.id for entry in result.entries] == ["2"]
+    result = client.search("journey")
+    assert [entry.id for entry in result.entries] == ["2"]
 
 
 def test_calibre_opds_search_collects_next_page_results(monkeypatch) -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  first_page = OPDSFeed(
-    id="catalog",
-    title="Catalog",
-    entries=[OPDSEntry(id="1", title="Ryan's Adventure")],
-    links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
-  )
-  second_page = OPDSFeed(
-    id="catalog",
-    title="Catalog",
-    entries=[OPDSEntry(id="2", title="Return of Ryan")],
-    links={},
-  )
+    client = CalibreOPDSClient("http://example.com/catalog")
+    first_page = OPDSFeed(
+        id="catalog",
+        title="Catalog",
+        entries=[OPDSEntry(id="1", title="Ryan's Adventure")],
+        links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
+    )
+    second_page = OPDSFeed(
+        id="catalog",
+        title="Catalog",
+        entries=[OPDSEntry(id="2", title="Return of Ryan")],
+        links={},
+    )
 
-  def fake_fetch(path=None, params=None):
-    if path == "search":
-      return first_page
-    if path == "http://example.com/catalog?page=2":
-      return second_page
-    if path is None and params is None:
-      return first_page
-    return first_page
+    def fake_fetch(path=None, params=None):
+        if path == "search":
+            return first_page
+        if path == "http://example.com/catalog?page=2":
+            return second_page
+        if path is None and params is None:
+            return first_page
+        return first_page
 
-  monkeypatch.setattr(client, "fetch_feed", fake_fetch)
+    monkeypatch.setattr(client, "fetch_feed", fake_fetch)
 
-  result = client.search("ryan")
-  assert [entry.id for entry in result.entries] == ["1", "2"]
+    result = client.search("ryan")
+    assert [entry.id for entry in result.entries] == ["1", "2"]
 
 
 def test_calibre_opds_search_supplements_with_local_navigation(monkeypatch) -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  search_feed = OPDSFeed(
-    id="catalog",
-    title="Catalog",
-    entries=[
-      OPDSEntry(id="book-1", title="Ryan's First Mission"),
-      OPDSEntry(
-        id="nav-authors",
-        title="Browse Authors",
-        links=[
-          OPDSLink(
-            href="http://example.com/catalog/authors",
-            rel="http://opds-spec.org/navigation",
-            type="application/atom+xml;profile=opds-catalog",
-          )
+    client = CalibreOPDSClient("http://example.com/catalog")
+    search_feed = OPDSFeed(
+        id="catalog",
+        title="Catalog",
+        entries=[
+            OPDSEntry(id="book-1", title="Ryan's First Mission"),
+            OPDSEntry(
+                id="nav-authors",
+                title="Browse Authors",
+                links=[
+                    OPDSLink(
+                        href="http://example.com/catalog/authors",
+                        rel="http://opds-spec.org/navigation",
+                        type="application/atom+xml;profile=opds-catalog",
+                    )
+                ],
+            ),
         ],
-      ),
-    ],
-    links={},
-  )
-  authors_feed = OPDSFeed(
-    id="authors",
-    title="Authors",
-    entries=[OPDSEntry(id="book-2", title="Chronicles of Ryan")],
-    links={},
-  )
+        links={},
+    )
+    authors_feed = OPDSFeed(
+        id="authors",
+        title="Authors",
+        entries=[OPDSEntry(id="book-2", title="Chronicles of Ryan")],
+        links={},
+    )
 
-  def fake_fetch(path=None, params=None):
-    if path == "search":
-      return search_feed
-    if path == "http://example.com/catalog/authors":
-      return authors_feed
-    if path is None and params is None:
-      return search_feed
-    return search_feed
+    def fake_fetch(path=None, params=None):
+        if path == "search":
+            return search_feed
+        if path == "http://example.com/catalog/authors":
+            return authors_feed
+        if path is None and params is None:
+            return search_feed
+        return search_feed
 
-  monkeypatch.setattr(client, "fetch_feed", fake_fetch)
+    monkeypatch.setattr(client, "fetch_feed", fake_fetch)
 
-  result = client.search("ryan")
-  assert [entry.id for entry in result.entries] == ["book-1", "book-2"]
+    result = client.search("ryan")
+    assert [entry.id for entry in result.entries] == ["book-1", "book-2"]
 
 
 def test_calibre_opds_browse_letter_traverses_next(monkeypatch) -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  root_feed = OPDSFeed(
-    id="catalog",
-    title="Browse Authors",
-    entries=[
-      OPDSEntry(
-        id="nav-a",
-        title="A",
-        links=[
-          OPDSLink(
-            href="http://example.com/catalog/authors/a",
-            rel="http://opds-spec.org/navigation",
-            type="application/atom+xml;profile=opds-catalog",
-          )
+    client = CalibreOPDSClient("http://example.com/catalog")
+    root_feed = OPDSFeed(
+        id="catalog",
+        title="Browse Authors",
+        entries=[
+            OPDSEntry(
+                id="nav-a",
+                title="A",
+                links=[
+                    OPDSLink(
+                        href="http://example.com/catalog/authors/a",
+                        rel="http://opds-spec.org/navigation",
+                        type="application/atom+xml;profile=opds-catalog",
+                    )
+                ],
+            )
         ],
-      )
-    ],
-    links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
-  )
-  page_two = OPDSFeed(
-    id="catalog",
-    title="Browse Authors",
-    entries=[
-      OPDSEntry(
-        id="nav-c",
-        title="C",
-        links=[
-          OPDSLink(
-            href="http://example.com/catalog/authors/c",
-            rel="http://opds-spec.org/navigation",
-            type="application/atom+xml;profile=opds-catalog",
-          )
+        links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
+    )
+    page_two = OPDSFeed(
+        id="catalog",
+        title="Browse Authors",
+        entries=[
+            OPDSEntry(
+                id="nav-c",
+                title="C",
+                links=[
+                    OPDSLink(
+                        href="http://example.com/catalog/authors/c",
+                        rel="http://opds-spec.org/navigation",
+                        type="application/atom+xml;profile=opds-catalog",
+                    )
+                ],
+            )
         ],
-      )
-    ],
-    links={},
-  )
-  letter_feed = OPDSFeed(
-    id="authors-c",
-    title="Authors starting with C",
-    entries=[OPDSEntry(id="author-1", title="Clarke, Arthur C.")],
-    links={},
-  )
+        links={},
+    )
+    letter_feed = OPDSFeed(
+        id="authors-c",
+        title="Authors starting with C",
+        entries=[OPDSEntry(id="author-1", title="Clarke, Arthur C.")],
+        links={},
+    )
 
-  def fake_fetch(href=None, params=None):
-    if not href:
-      return root_feed
-    if href == "http://example.com/catalog?page=2":
-      return page_two
-    if href == "http://example.com/catalog/authors/c":
-      return letter_feed
-    return root_feed
+    def fake_fetch(href=None, params=None):
+        if not href:
+            return root_feed
+        if href == "http://example.com/catalog?page=2":
+            return page_two
+        if href == "http://example.com/catalog/authors/c":
+            return letter_feed
+        return root_feed
 
-  monkeypatch.setattr(client, "fetch_feed", fake_fetch)
+    monkeypatch.setattr(client, "fetch_feed", fake_fetch)
 
-  result = client.browse_letter("C")
-  assert [entry.id for entry in result.entries] == ["author-1"]
+    result = client.browse_letter("C")
+    assert [entry.id for entry in result.entries] == ["author-1"]
 
 
-def test_calibre_opds_browse_letter_filters_when_missing_navigation(monkeypatch) -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  titles_feed = OPDSFeed(
-    id="catalog",
-    title="Browse Titles",
-    entries=[
-      OPDSEntry(id="book-1", title="The Moon is a Harsh Mistress"),
-      OPDSEntry(id="book-2", title="Another Story"),
-    ],
-    links={},
-  )
+def test_calibre_opds_browse_letter_filters_when_missing_navigation(
+    monkeypatch,
+) -> None:
+    client = CalibreOPDSClient("http://example.com/catalog")
+    titles_feed = OPDSFeed(
+        id="catalog",
+        title="Browse Titles",
+        entries=[
+            OPDSEntry(id="book-1", title="The Moon is a Harsh Mistress"),
+            OPDSEntry(id="book-2", title="Another Story"),
+        ],
+        links={},
+    )
 
-  def fake_fetch(href=None, params=None):
-    return titles_feed
+    def fake_fetch(href=None, params=None):
+        return titles_feed
 
-  monkeypatch.setattr(client, "fetch_feed", fake_fetch)
+    monkeypatch.setattr(client, "fetch_feed", fake_fetch)
 
-  result = client.browse_letter("M")
-  assert [entry.id for entry in result.entries] == ["book-1"]
+    result = client.browse_letter("M")
+    assert [entry.id for entry in result.entries] == ["book-1"]
 
 
 def test_calibre_opds_browse_letter_collects_paginated_entries(monkeypatch) -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  first_page = OPDSFeed(
-    id="catalog",
-    title="Browse Titles",
-    entries=[
-      OPDSEntry(id="book-1", title="Ryan's First Adventure"),
-      OPDSEntry(id="book-2", title="Another Tale"),
-    ],
-    links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
-  )
-  second_page = OPDSFeed(
-    id="catalog",
-    title="Browse Titles",
-    entries=[OPDSEntry(id="book-3", title="Return of Ryan")],
-    links={},
-  )
+    client = CalibreOPDSClient("http://example.com/catalog")
+    first_page = OPDSFeed(
+        id="catalog",
+        title="Browse Titles",
+        entries=[
+            OPDSEntry(id="book-1", title="Ryan's First Adventure"),
+            OPDSEntry(id="book-2", title="Another Tale"),
+        ],
+        links={"next": OPDSLink(href="http://example.com/catalog?page=2", rel="next")},
+    )
+    second_page = OPDSFeed(
+        id="catalog",
+        title="Browse Titles",
+        entries=[OPDSEntry(id="book-3", title="Return of Ryan")],
+        links={},
+    )
 
-  def fake_fetch(href=None, params=None):
-    if not href:
-      return first_page
-    if href == "http://example.com/catalog?page=2":
-      return second_page
-    return first_page
+    def fake_fetch(href=None, params=None):
+        if not href:
+            return first_page
+        if href == "http://example.com/catalog?page=2":
+            return second_page
+        return first_page
 
-  monkeypatch.setattr(client, "fetch_feed", fake_fetch)
+    monkeypatch.setattr(client, "fetch_feed", fake_fetch)
 
-  result = client.browse_letter("R")
-  assert [entry.id for entry in result.entries] == ["book-1", "book-3"]
+    result = client.browse_letter("R")
+    assert [entry.id for entry in result.entries] == ["book-1", "book-3"]
 
 
 def test_calibre_opds_browse_letter_collects_paginated_navigation(monkeypatch) -> None:
-  client = CalibreOPDSClient("http://example.com/catalog")
-  root_feed = OPDSFeed(
-    id="catalog",
-    title="Browse Authors",
-    entries=[
-      OPDSEntry(
-        id="nav-a",
-        title="A",
-        links=[
-          OPDSLink(
-            href="http://example.com/catalog/authors/a",
-            rel="http://opds-spec.org/navigation",
-            type="application/atom+xml;profile=opds-catalog",
-          )
+    client = CalibreOPDSClient("http://example.com/catalog")
+    root_feed = OPDSFeed(
+        id="catalog",
+        title="Browse Authors",
+        entries=[
+            OPDSEntry(
+                id="nav-a",
+                title="A",
+                links=[
+                    OPDSLink(
+                        href="http://example.com/catalog/authors/a",
+                        rel="http://opds-spec.org/navigation",
+                        type="application/atom+xml;profile=opds-catalog",
+                    )
+                ],
+            ),
+            OPDSEntry(
+                id="nav-r",
+                title="R",
+                links=[
+                    OPDSLink(
+                        href="http://example.com/catalog/authors/r",
+                        rel="http://opds-spec.org/navigation",
+                        type="application/atom+xml;profile=opds-catalog",
+                    )
+                ],
+            ),
         ],
-      ),
-      OPDSEntry(
-        id="nav-r",
-        title="R",
-        links=[
-          OPDSLink(
-            href="http://example.com/catalog/authors/r",
-            rel="http://opds-spec.org/navigation",
-            type="application/atom+xml;profile=opds-catalog",
-          )
+        links={},
+    )
+    letter_feed = OPDSFeed(
+        id="authors-r",
+        title="Authors — R",
+        entries=[
+            OPDSEntry(id="author-1", title="Ryan, Alice"),
         ],
-      ),
-    ],
-    links={},
-  )
-  letter_feed = OPDSFeed(
-    id="authors-r",
-    title="Authors — R",
-    entries=[
-      OPDSEntry(id="author-1", title="Ryan, Alice"),
-    ],
-    links={"next": OPDSLink(href="http://example.com/catalog/authors/r?page=2", rel="next")},
-  )
-  letter_page_two = OPDSFeed(
-    id="authors-r",
-    title="Authors — R",
-    entries=[OPDSEntry(id="author-2", title="Ryan, Bob")],
-    links={},
-  )
+        links={
+            "next": OPDSLink(
+                href="http://example.com/catalog/authors/r?page=2", rel="next"
+            )
+        },
+    )
+    letter_page_two = OPDSFeed(
+        id="authors-r",
+        title="Authors — R",
+        entries=[OPDSEntry(id="author-2", title="Ryan, Bob")],
+        links={},
+    )
 
-  def fake_fetch(href=None, params=None):
-    if not href:
-      return root_feed
-    if href == "http://example.com/catalog/authors/r":
-      return letter_feed
-    if href == "http://example.com/catalog/authors/r?page=2":
-      return letter_page_two
-    return root_feed
+    def fake_fetch(href=None, params=None):
+        if not href:
+            return root_feed
+        if href == "http://example.com/catalog/authors/r":
+            return letter_feed
+        if href == "http://example.com/catalog/authors/r?page=2":
+            return letter_page_two
+        return root_feed
 
-  monkeypatch.setattr(client, "fetch_feed", fake_fetch)
+    monkeypatch.setattr(client, "fetch_feed", fake_fetch)
 
-  result = client.browse_letter("R")
-  assert [entry.id for entry in result.entries] == ["author-1", "author-2"]
+    result = client.browse_letter("R")
+    assert [entry.id for entry in result.entries] == ["author-1", "author-2"]
diff --git a/tests/test_chapter_overrides.py b/tests/test_chapter_overrides.py
index 27f942d..7ffbe1a 100644
--- a/tests/test_chapter_overrides.py
+++ b/tests/test_chapter_overrides.py
@@ -43,7 +43,11 @@ def _install_dependency_stubs() -> None:
         setattr(numpy_stub, "float32", "float32")
         setattr(numpy_stub, "array", lambda data, dtype=None: data)
         setattr(numpy_stub, "asarray", lambda data, dtype=None: data)
-        setattr(numpy_stub, "concatenate", lambda seq, axis=0: sum((list(item) for item in seq), []))
+        setattr(
+            numpy_stub,
+            "concatenate",
+            lambda seq, axis=0: sum((list(item) for item in seq), []),
+        )
         sys.modules["numpy"] = numpy_stub
 
     if "soundfile" not in sys.modules:
@@ -117,7 +121,9 @@ def test_apply_chapter_overrides_with_custom_text() -> None:
         {"index": 1, "enabled": False},
     ]
 
-    selected, metadata, diagnostics = _apply_chapter_overrides(_sample_chapters(), overrides)
+    selected, metadata, diagnostics = _apply_chapter_overrides(
+        _sample_chapters(), overrides
+    )
 
     assert len(selected) == 1
     assert selected[0].title == "Intro"
@@ -132,7 +138,9 @@ def test_apply_chapter_overrides_uses_original_content_when_text_missing() -> No
         {"index": 1, "enabled": True},
     ]
 
-    selected, metadata, diagnostics = _apply_chapter_overrides(_sample_chapters(), overrides)
+    selected, metadata, diagnostics = _apply_chapter_overrides(
+        _sample_chapters(), overrides
+    )
 
     assert len(selected) == 1
     assert selected[0].title == "Chapter 2"
@@ -152,7 +160,9 @@ def test_apply_chapter_overrides_collects_metadata_updates() -> None:
         }
     ]
 
-    selected, metadata, diagnostics = _apply_chapter_overrides(_sample_chapters(), overrides)
+    selected, metadata, diagnostics = _apply_chapter_overrides(
+        _sample_chapters(), overrides
+    )
 
     assert len(selected) == 1
     assert metadata == {"artist": "Test Author", "year": "2024"}
@@ -164,7 +174,9 @@ def test_apply_chapter_overrides_reports_diagnostics_for_invalid_payload() -> No
         {"enabled": True, "title": "Missing"},
     ]
 
-    selected, metadata, diagnostics = _apply_chapter_overrides(_sample_chapters(), overrides)
+    selected, metadata, diagnostics = _apply_chapter_overrides(
+        _sample_chapters(), overrides
+    )
 
     assert selected == []
     assert metadata == {}
diff --git a/tests/test_chunk_helpers.py b/tests/test_chunk_helpers.py
index b937358..ee9da79 100644
--- a/tests/test_chunk_helpers.py
+++ b/tests/test_chunk_helpers.py
@@ -27,7 +27,9 @@ def test_chunk_voice_spec_prefers_chunk_overrides() -> None:
 
 
 def test_chunk_voice_spec_falls_back_to_speaker_voice() -> None:
-    job = SimpleNamespace(voice="base_voice", speakers={"narrator": {"voice": "speaker_voice"}})
+    job = SimpleNamespace(
+        voice="base_voice", speakers={"narrator": {"voice": "speaker_voice"}}
+    )
     chunk = {"speaker_id": "narrator"}
 
     assert _chunk_voice_spec(job, chunk, "fallback") == "speaker_voice"
diff --git a/tests/test_conversion_chapter_titles.py b/tests/test_conversion_chapter_titles.py
index 76805c6..5fe6a4d 100644
--- a/tests/test_conversion_chapter_titles.py
+++ b/tests/test_conversion_chapter_titles.py
@@ -74,7 +74,9 @@ def test_format_spoken_chapter_title_adds_prefix() -> None:
 
 
 def test_format_spoken_chapter_title_respects_existing_prefix() -> None:
-    assert _format_spoken_chapter_title("Chapter 2: Story", 2, True) == "Chapter 2: Story"
+    assert (
+        _format_spoken_chapter_title("Chapter 2: Story", 2, True) == "Chapter 2: Story"
+    )
 
 
 def test_format_spoken_chapter_title_handles_empty_title() -> None:
@@ -82,7 +84,10 @@ def test_format_spoken_chapter_title_handles_empty_title() -> None:
 
 
 def test_format_spoken_chapter_title_trims_delimiters() -> None:
-    assert _format_spoken_chapter_title("7 - Into the Wild", 7, True) == "Chapter 7. Into the Wild"
+    assert (
+        _format_spoken_chapter_title("7 - Into the Wild", 7, True)
+        == "Chapter 7. Into the Wild"
+    )
 
 
 def test_headings_equivalent_ignores_case_and_prefix() -> None:
@@ -90,7 +95,9 @@ def test_headings_equivalent_ignores_case_and_prefix() -> None:
 
 
 def test_strip_duplicate_heading_line_removes_first_match() -> None:
-    text, removed = _strip_duplicate_heading_line("Chapter 3: Intro\nBody text", "Chapter 3: Intro")
+    text, removed = _strip_duplicate_heading_line(
+        "Chapter 3: Intro\nBody text", "Chapter 3: Intro"
+    )
     assert removed is True
     assert text.strip() == "Body text"
 
diff --git a/tests/test_conversion_series.py b/tests/test_conversion_series.py
index fb85138..9bb8def 100644
--- a/tests/test_conversion_series.py
+++ b/tests/test_conversion_series.py
@@ -117,4 +117,4 @@ def test_series_number_preserves_decimal_positions() -> None:
 
     intro_text = _build_title_intro_text(metadata, "interlude.mp3")
 
-    assert "Book 2.5 of the Chronicles." in intro_text
\ No newline at end of file
+    assert "Book 2.5 of the Chronicles." in intro_text
diff --git a/tests/test_conversion_voice_resolution.py b/tests/test_conversion_voice_resolution.py
index 4987c5d..e791306 100644
--- a/tests/test_conversion_voice_resolution.py
+++ b/tests/test_conversion_voice_resolution.py
@@ -14,14 +14,14 @@ def _sample_job(formula: str) -> Job:
     return cast(
         Job,
         SimpleNamespace(
-        voice="__custom_mix",
-        speakers={
-            "narrator": {
-                "resolved_voice": formula,
-            }
-        },
-        chapters=[],
-        chunks=[{}],
+            voice="__custom_mix",
+            speakers={
+                "narrator": {
+                    "resolved_voice": formula,
+                }
+            },
+            chapters=[],
+            chunks=[{}],
         ),
     )
 
diff --git a/tests/test_date_normalization_comprehensive.py b/tests/test_date_normalization_comprehensive.py
index 393feee..1bc04a0 100644
--- a/tests/test_date_normalization_comprehensive.py
+++ b/tests/test_date_normalization_comprehensive.py
@@ -1,15 +1,21 @@
 import pytest
-from abogen.kokoro_text_normalization import _normalize_grouped_numbers, ApostropheConfig
+from abogen.kokoro_text_normalization import (
+    _normalize_grouped_numbers,
+    ApostropheConfig,
+)
+
 
 @pytest.fixture
 def cfg():
     return ApostropheConfig(convert_numbers=True, year_pronunciation_mode="american")
 
+
 def normalize(text, config):
     return _normalize_grouped_numbers(text, config)
 
+
 class TestDateNormalization:
-    
+
     def test_standard_years(self, cfg):
         # 1990 -> nineteen hundred ninety
         assert "nineteen hundred ninety" in normalize("In 1990, the web was born.", cfg)
@@ -18,8 +24,10 @@ class TestDateNormalization:
         # 2023 -> twenty twenty-three
         assert "twenty twenty-three" in normalize("It is currently 2023.", cfg)
         # 1905 -> nineteen hundred oh five
-        assert "nineteen hundred oh five" in normalize("In 1905, Einstein published.", cfg)
-        
+        assert "nineteen hundred oh five" in normalize(
+            "In 1905, Einstein published.", cfg
+        )
+
     def test_future_years(self, cfg):
         # 3400 -> thirty-four hundred
         assert "thirty-four hundred" in normalize("In the year 3400, we fly.", cfg)
@@ -29,13 +37,13 @@ class TestDateNormalization:
     def test_years_with_markers(self, cfg):
         # 1021 BC -> ten twenty-one
         assert "ten twenty-one" in normalize("It happened in 1021 BC.", cfg)
-        # 4000 BCE -> forty hundred (or four thousand?) 
-        # _format_year_like logic: 
+        # 4000 BCE -> forty hundred (or four thousand?)
+        # _format_year_like logic:
         # if value % 1000 == 0: return "X thousand"
-        # 4000 -> four thousand. 
+        # 4000 -> four thousand.
         # Let's check 4001 -> forty oh one
         assert "forty oh one" in normalize("Ancient times 4001 BCE.", cfg)
-        
+
     def test_addresses_explicit(self, cfg):
         # "address" keyword present -> should NOT be year
         # 1925 -> one thousand nine hundred twenty-five (default num2words)
@@ -46,11 +54,11 @@ class TestDateNormalization:
         assert "one thousand" in res or "nineteen hundred" in res
 
         res = normalize("Please send it to the address: 3400 North Blvd.", cfg)
-        assert "thirty-four hundred" not in res # Should not be year style
-        assert "three thousand" in res or "thirty-four hundred" in res 
-        # Wait, "thirty-four hundred" IS how you say 3400 in num2words sometimes? 
+        assert "thirty-four hundred" not in res  # Should not be year style
+        assert "three thousand" in res or "thirty-four hundred" in res
+        # Wait, "thirty-four hundred" IS how you say 3400 in num2words sometimes?
         # num2words(3400) -> "three thousand, four hundred" usually.
-        # Let's verify what "thirty-four hundred" implies. 
+        # Let's verify what "thirty-four hundred" implies.
         # If it's a year: "thirty-four hundred".
         # If it's a number: "three thousand four hundred".
         assert "three thousand" in res
@@ -62,9 +70,9 @@ class TestDateNormalization:
 
     def test_ambiguous_numbers(self, cfg):
         # Just a number, no "address", no markers. Should default to year if 4 digits 1000-9999
-        assert "nineteen hundred fifty" in normalize("I have 1950 apples.", cfg) 
+        assert "nineteen hundred fifty" in normalize("I have 1950 apples.", cfg)
         # This is a known limitation/feature: it aggressively identifies years.
-        
+
     def test_specific_user_examples(self, cfg):
         # 1021
         assert "ten twenty-one" in normalize("1021", cfg)
@@ -77,10 +85,10 @@ class TestDateNormalization:
         # Simulating a title or sentence from the book
         # "The Rise of the Robots: Technology and the Threat of a Jobless Future"
         # Maybe it mentions a year like 2015 (pub date) or a future date.
-        
+
         # "In 2015, Martin Ford wrote..."
         assert "twenty fifteen" in normalize("In 2015, Martin Ford wrote...", cfg)
-        
+
         # "By 2100, robots will..."
         assert "twenty-one hundred" in normalize("By 2100, robots will...", cfg)
 
@@ -113,4 +121,3 @@ class TestDateNormalization:
         res = normalize("The addresses are 1925 and 1926.", cfg)
         # Expectation: should probably be numbers, not years.
         assert "nineteen twenty-five" not in res
-
diff --git a/tests/test_debug_tts_samples.py b/tests/test_debug_tts_samples.py
index 6f0a088..a936fb2 100644
--- a/tests/test_debug_tts_samples.py
+++ b/tests/test_debug_tts_samples.py
@@ -4,7 +4,12 @@ from pathlib import Path
 import numpy as np
 import pytest
 
-from abogen.debug_tts_samples import DEBUG_TTS_SAMPLES, MARKER_PREFIX, MARKER_SUFFIX, iter_expected_codes
+from abogen.debug_tts_samples import (
+    DEBUG_TTS_SAMPLES,
+    MARKER_PREFIX,
+    MARKER_SUFFIX,
+    iter_expected_codes,
+)
 from abogen.kokoro_text_normalization import HAS_NUM2WORDS, normalize_for_pipeline
 from abogen.normalization_settings import build_apostrophe_config
 from abogen.text_extractor import extract_from_path
@@ -16,7 +21,9 @@ def test_debug_epub_contains_all_codes():
     assert epub_path.exists()
 
     extraction = extract_from_path(epub_path)
-    combined = extraction.combined_text or "\n\n".join((c.text or "") for c in extraction.chapters)
+    combined = extraction.combined_text or "\n\n".join(
+        (c.text or "") for c in extraction.chapters
+    )
 
     for code in iter_expected_codes():
         marker = f"{MARKER_PREFIX}{code}{MARKER_SUFFIX}"
@@ -32,7 +39,9 @@ def test_debug_samples_normalize_smoke():
     runtime = dict(settings)
 
     normalized = {
-        sample.code: normalize_for_pipeline(sample.text, config=apostrophe, settings=runtime)
+        sample.code: normalize_for_pipeline(
+            sample.text, config=apostrophe, settings=runtime
+        )
         for sample in DEBUG_TTS_SAMPLES
     }
 
@@ -69,7 +78,9 @@ def test_settings_debug_route_writes_manifest(tmp_path, monkeypatch):
             audio[::100] = 0.1
             yield _Seg(audio)
 
-    monkeypatch.setattr(runner, "_load_pipeline", lambda language, use_gpu: DummyPipeline())
+    monkeypatch.setattr(
+        runner, "_load_pipeline", lambda language, use_gpu: DummyPipeline()
+    )
 
     app = create_app(
         {
@@ -87,14 +98,18 @@ def test_settings_debug_route_writes_manifest(tmp_path, monkeypatch):
         assert "/settings/debug/" in location
 
         # Extract run id from /settings/debug/<run_id>
-        run_id = location.rsplit("/settings/debug/", 1)[1].split("?", 1)[0].split("#", 1)[0]
+        run_id = (
+            location.rsplit("/settings/debug/", 1)[1].split("?", 1)[0].split("#", 1)[0]
+        )
         manifest_path = tmp_path / "debug" / run_id / "manifest.json"
         assert manifest_path.exists()
 
         manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
         filenames = {item["filename"] for item in manifest.get("artifacts", [])}
         assert "overall.wav" in filenames
-        assert any(name.startswith("case_") and name.endswith(".wav") for name in filenames)
+        assert any(
+            name.startswith("case_") and name.endswith(".wav") for name in filenames
+        )
 
 
 def test_debug_samples_have_minimum_per_category():
@@ -125,7 +140,9 @@ def test_debug_runner_resolves_profile_voice_before_pipeline(tmp_path, monkeypat
     from abogen.webui import debug_tts_runner as runner
 
     # Stub voice setting resolution so we don't depend on the user's profile file.
-    monkeypatch.setattr(runner, "_resolve_voice_setting", lambda value: ("af_heart", "AM HQ Alt", None))
+    monkeypatch.setattr(
+        runner, "_resolve_voice_setting", lambda value: ("af_heart", "AM HQ Alt", None)
+    )
 
     calls = []
 
@@ -139,7 +156,9 @@ def test_debug_runner_resolves_profile_voice_before_pipeline(tmp_path, monkeypat
             audio = np.zeros(int(0.05 * runner.SAMPLE_RATE), dtype="float32")
             yield _Seg(audio)
 
-    monkeypatch.setattr(runner, "_load_pipeline", lambda language, use_gpu: DummyPipeline())
+    monkeypatch.setattr(
+        runner, "_load_pipeline", lambda language, use_gpu: DummyPipeline()
+    )
 
     settings = {
         "language": "en",
@@ -152,4 +171,6 @@ def test_debug_runner_resolves_profile_voice_before_pipeline(tmp_path, monkeypat
     assert manifest.get("run_id")
     assert calls
     # Must not pass through the profile:* string.
-    assert all(isinstance(v, str) and not v.lower().startswith("profile:") for v in calls)
+    assert all(
+        isinstance(v, str) and not v.lower().startswith("profile:") for v in calls
+    )
diff --git a/tests/test_epub_content_slicing.py b/tests/test_epub_content_slicing.py
index 16c616b..829e233 100644
--- a/tests/test_epub_content_slicing.py
+++ b/tests/test_epub_content_slicing.py
@@ -5,10 +5,11 @@ import sys
 from ebooklib import epub
 
 # Ensure import path
-sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
 from abogen.book_parser import get_book_parser
 
+
 class TestEpubContentSlicing(unittest.TestCase):
     """
     Tests for the complex content slicing logic in _execute_nav_parsing_logic.
@@ -34,7 +35,7 @@ class TestEpubContentSlicing(unittest.TestCase):
         book = epub.EpubBook()
         book.set_identifier("slice123")
         book.set_title("Slicing Test Book")
-        
+
         # Create a single content file with two sections
         content_html = """
         <html>
@@ -50,7 +51,7 @@ class TestEpubContentSlicing(unittest.TestCase):
         c1 = epub.EpubHtml(title="Full Content", file_name="content.xhtml", lang="en")
         c1.content = content_html
         book.add_item(c1)
-        
+
         # Create Nav that points to anchors in the SAME file
         # We use EpubHtml for Nav to control content exactly without ebooklib interference
         nav_html = """
@@ -64,55 +65,56 @@ class TestEpubContentSlicing(unittest.TestCase):
         nav = epub.EpubHtml(title="Nav", file_name="nav.xhtml")
         nav.content = nav_html
         book.add_item(nav)
-        
+
         book.spine = [nav, c1]
-        
+
         epub.write_epub(self.epub_path, book)
-        
+
         # OPF Patching to valid crash
         import zipfile
+
         patched = False
-        with zipfile.ZipFile(self.epub_path, 'r') as zin:
-            opf_content = zin.read('EPUB/content.opf').decode('utf-8')
+        with zipfile.ZipFile(self.epub_path, "r") as zin:
+            opf_content = zin.read("EPUB/content.opf").decode("utf-8")
             if 'toc="ncx"' in opf_content:
-                opf_content = opf_content.replace('toc="ncx"', '')
+                opf_content = opf_content.replace('toc="ncx"', "")
                 patched = True
-        
+
             if patched:
                 TEMP_EPUB = self.epub_path + ".temp"
-                with zipfile.ZipFile(TEMP_EPUB, 'w') as zout:
+                with zipfile.ZipFile(TEMP_EPUB, "w") as zout:
                     for item in zin.infolist():
-                        if item.filename == 'EPUB/content.opf':
+                        if item.filename == "EPUB/content.opf":
                             zout.writestr(item, opf_content)
                         else:
                             zout.writestr(item, zin.read(item.filename))
-        
+
         if patched:
             shutil.move(TEMP_EPUB, self.epub_path)
-            
+
         # Parse
         parser = get_book_parser(self.epub_path)
         parser.process_content()
         chapters = parser.get_chapters()
-        
+
         # Filter Nav/Intro
         chapters = [c for c in chapters if "Chapter" in c[1]]
-        
+
         self.assertEqual(len(chapters), 2)
         self.assertEqual(chapters[0][1], "Chapter 1")
         self.assertEqual(chapters[1][1], "Chapter 2")
-        
+
         # Check content of Chapter 1
         # It should contain "Text for chapter 1" but NOT "Text for chapter 2"
         # The parser logic slices from start_pos to next_pos
         text1 = parser.content_texts[chapters[0][0]]
         self.assertIn("Text for chapter 1", text1)
         self.assertNotIn("Text for chapter 2", text1)
-        
+
         # Check content of Chapter 2
         text2 = parser.content_texts[chapters[1][0]]
         self.assertIn("Text for chapter 2", text2)
-        
+
     def test_list_renumbering(self):
         """
         Test that ordered lists are re-numbered when slicing.
@@ -121,7 +123,7 @@ class TestEpubContentSlicing(unittest.TestCase):
         book = epub.EpubBook()
         book.set_identifier("list123")
         book.set_title("List Test Book")
-        
+
         content_html = """
         <html>
             <body>
@@ -141,7 +143,7 @@ class TestEpubContentSlicing(unittest.TestCase):
         c1 = epub.EpubHtml(title="Content", file_name="content.xhtml", lang="en")
         c1.content = content_html
         book.add_item(c1)
-        
+
         nav_html = """
         <nav epub:type="toc">
             <ol>
@@ -154,46 +156,48 @@ class TestEpubContentSlicing(unittest.TestCase):
         nav.content = nav_html
         book.add_item(nav)
         book.spine = [nav, c1]
-        
+
         epub.write_epub(self.epub_path, book)
-        
+
         # Patch
         import zipfile
+
         patched = False
-        with zipfile.ZipFile(self.epub_path, 'r') as zin:
-            opf_content = zin.read('EPUB/content.opf').decode('utf-8')
+        with zipfile.ZipFile(self.epub_path, "r") as zin:
+            opf_content = zin.read("EPUB/content.opf").decode("utf-8")
             if 'toc="ncx"' in opf_content:
-                opf_content = opf_content.replace('toc="ncx"', '')
+                opf_content = opf_content.replace('toc="ncx"', "")
                 patched = True
             if patched:
                 TEMP_EPUB = self.epub_path + ".temp"
-                with zipfile.ZipFile(TEMP_EPUB, 'w') as zout:
+                with zipfile.ZipFile(TEMP_EPUB, "w") as zout:
                     for item in zin.infolist():
-                        if item.filename == 'EPUB/content.opf':
+                        if item.filename == "EPUB/content.opf":
                             zout.writestr(item, opf_content)
                         else:
                             zout.writestr(item, zin.read(item.filename))
         if patched:
             shutil.move(TEMP_EPUB, self.epub_path)
-            
+
         parser = get_book_parser(self.epub_path)
         parser.process_content()
         chapters = parser.get_chapters()
         chapters = [c for c in chapters if "Part" in c[1]]
-        
+
         self.assertEqual(len(chapters), 2)
-        
+
         # Check Part 1 text
         text1 = parser.content_texts[chapters[0][0]]
         # The parser explicitly replaces li with "1) Item A" style text
         self.assertIn("1) Item A", text1)
         self.assertIn("2) Item B", text1)
-        
+
         # Check Part 2 text
         text2 = parser.content_texts[chapters[1][0]]
         # Should convert start="3" to "3) Item C"
         self.assertIn("3) Item C", text2)
         self.assertIn("4) Item D", text2)
 
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/test_epub_exporter.py b/tests/test_epub_exporter.py
index 4b5f847..0bdef3a 100644
--- a/tests/test_epub_exporter.py
+++ b/tests/test_epub_exporter.py
@@ -37,8 +37,20 @@ def test_build_epub3_package_creates_expected_structure(tmp_path) -> None:
         },
     ]
     chunk_markers = [
-        {"id": "chap0000_p0000", "chapter_index": 0, "chunk_index": 0, "start": 0.0, "end": 1.2},
-        {"id": "chap0001_p0000", "chapter_index": 1, "chunk_index": 0, "start": 1.2, "end": 2.4},
+        {
+            "id": "chap0000_p0000",
+            "chapter_index": 0,
+            "chunk_index": 0,
+            "start": 0.0,
+            "end": 1.2,
+        },
+        {
+            "id": "chap0001_p0000",
+            "chapter_index": 1,
+            "chunk_index": 0,
+            "start": 1.2,
+            "end": 2.4,
+        },
     ]
     chapter_markers = [
         {"index": 1, "title": "Chapter 1", "start": 0.0, "end": 1.2},
@@ -76,7 +88,7 @@ def test_build_epub3_package_creates_expected_structure(tmp_path) -> None:
         chapter_doc = archive.read("OEBPS/text/chapter_0001.xhtml").decode("utf-8")
         assert "Hello world." in chapter_doc
         smil_doc = archive.read("OEBPS/smil/chapter_0001.smil").decode("utf-8")
-        assert "clipBegin=\"00:00:00.000\"" in smil_doc
+        assert 'clipBegin="00:00:00.000"' in smil_doc
         opf_doc = archive.read("OEBPS/content.opf").decode("utf-8")
         assert "media-overlay" in opf_doc
         assert "media:duration" in opf_doc
@@ -145,7 +157,13 @@ def test_epub3_preserves_original_whitespace(tmp_path) -> None:
     ]
 
     chunk_markers = [
-        {"id": chunk["id"], "chapter_index": 0, "chunk_index": chunk["chunk_index"], "start": None, "end": None}
+        {
+            "id": chunk["id"],
+            "chapter_index": 0,
+            "chunk_index": chunk["chunk_index"],
+            "start": None,
+            "end": None,
+        }
         for chunk in chunks
     ]
 
@@ -174,7 +192,9 @@ def test_epub3_preserves_original_whitespace(tmp_path) -> None:
     assert "Second line" in chunk_section
     assert "Third paragraph." in chunk_section
 
-    match = re.search(r"<pre class=\"chapter-original\"[^>]*>(.*?)</pre>", chapter_doc, re.DOTALL)
+    match = re.search(
+        r"<pre class=\"chapter-original\"[^>]*>(.*?)</pre>", chapter_doc, re.DOTALL
+    )
     assert match is not None
     original_text = html.unescape(match.group(1))
     assert "Second line\n\nThird paragraph." in original_text
@@ -219,7 +239,13 @@ def test_epub3_sentence_chunks_render_as_paragraphs(tmp_path) -> None:
     ]
 
     chunk_markers = [
-        {"id": chunk["id"], "chapter_index": 0, "chunk_index": chunk["chunk_index"], "start": None, "end": None}
+        {
+            "id": chunk["id"],
+            "chapter_index": 0,
+            "chunk_index": chunk["chunk_index"],
+            "start": None,
+            "end": None,
+        }
         for chunk in chunks
     ]
 
@@ -244,11 +270,11 @@ def test_epub3_sentence_chunks_render_as_paragraphs(tmp_path) -> None:
 
     assert '<div class="chunk"' not in chapter_doc
     assert chapter_doc.count('<p class="chunk-group"') == 2
-    assert 'First sentence.' in chapter_doc
-    assert 'Second sentence in same paragraph.' in chapter_doc
+    assert "First sentence." in chapter_doc
+    assert "Second sentence in same paragraph." in chapter_doc
 
     first_paragraph_start = chapter_doc.find('<p class="chunk-group"')
-    first_paragraph_end = chapter_doc.find('</p>', first_paragraph_start)
+    first_paragraph_end = chapter_doc.find("</p>", first_paragraph_start)
     first_paragraph = chapter_doc[first_paragraph_start:first_paragraph_end]
     assert "First sentence." in first_paragraph
-    assert "Second sentence in same paragraph." in first_paragraph
\ No newline at end of file
+    assert "Second sentence in same paragraph." in first_paragraph
diff --git a/tests/test_epub_heuristic_nav.py b/tests/test_epub_heuristic_nav.py
index a69a374..eb5a418 100644
--- a/tests/test_epub_heuristic_nav.py
+++ b/tests/test_epub_heuristic_nav.py
@@ -5,10 +5,11 @@ import sys
 from ebooklib import epub
 
 # Ensure import path
-sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
 from abogen.book_parser import get_book_parser
 
+
 class TestEpubHeuristicNav(unittest.TestCase):
     """
     Tests for the heuristic fallback in _identify_nav_item (Step 4),
@@ -31,12 +32,12 @@ class TestEpubHeuristicNav(unittest.TestCase):
         book = epub.EpubBook()
         book.set_identifier("heuristic123")
         book.set_title("Heuristic Test Book")
-        
+
         # 1. Add Content
         c1 = epub.EpubHtml(title="Chapter 1", file_name="chap1.xhtml", lang="en")
         c1.content = "<h1>Chapter 1</h1><p>Text</p>"
         book.add_item(c1)
-        
+
         # 2. Add a Nav file BUT as a regular EpubHtml (ITEM_DOCUMENT)
         # We do NOT use EpubNav. We do NOT look like a standard nav file if possible,
         # but content must contain the magical signature.
@@ -52,66 +53,71 @@ class TestEpubHeuristicNav(unittest.TestCase):
         </body>
         </html>
         """
-        # Filename intentionally generic/obscure to avoid filename-based heuristics 
+        # Filename intentionally generic/obscure to avoid filename-based heuristics
         # (though current code checks content, not just filename)
         nav_file = epub.EpubHtml(title="Hidden Nav", file_name="content_toc.xhtml")
         nav_file.content = nav_content
         book.add_item(nav_file)
-        
+
         # 3. Setup Spine
         book.spine = [nav_file, c1]
-        
+
         # 4. Write EPUB
         epub.write_epub(self.epub_path, book)
-        
+
         # 5. Patch OPF to ensure ebooklib didn't sneakily add ITEM_NAVIGATION or toc="ncx"
         import zipfile
+
         patched = False
-        with zipfile.ZipFile(self.epub_path, 'r') as zin:
-            opf_content = zin.read('EPUB/content.opf').decode('utf-8')
-            
+        with zipfile.ZipFile(self.epub_path, "r") as zin:
+            opf_content = zin.read("EPUB/content.opf").decode("utf-8")
+
             # Remove toc="ncx" attribute if present (causes crash if no NCX)
             if 'toc="ncx"' in opf_content:
-                opf_content = opf_content.replace('toc="ncx"', '')
+                opf_content = opf_content.replace('toc="ncx"', "")
                 patched = True
-                
+
             # Ideally we'd verify properties="nav" isn't there, but EpubHtml shouldn't add it.
             # If ebooklib added it, we might need to strip it to force heuristic.
             if 'properties="nav"' in opf_content:
-                opf_content = opf_content.replace('properties="nav"', '')
+                opf_content = opf_content.replace('properties="nav"', "")
                 patched = True
 
             if patched:
                 TEMP_EPUB = self.epub_path + ".temp"
-                with zipfile.ZipFile(TEMP_EPUB, 'w') as zout:
+                with zipfile.ZipFile(TEMP_EPUB, "w") as zout:
                     for item in zin.infolist():
-                        if item.filename == 'EPUB/content.opf':
+                        if item.filename == "EPUB/content.opf":
                             zout.writestr(item, opf_content)
                         else:
                             zout.writestr(item, zin.read(item.filename))
-        
+
         if patched:
             shutil.move(TEMP_EPUB, self.epub_path)
 
         # 6. Verify our setup: Ensure NO ITEM_NAVIGATION exists
         # We can inspect using ebooklib again
         import ebooklib
+
         check_book = epub.read_epub(self.epub_path)
         nav_items = list(check_book.get_items_of_type(ebooklib.ITEM_NAVIGATION))
-        self.assertEqual(len(nav_items), 0, "Setup failed: explicit navigation item found!")
-        
+        self.assertEqual(
+            len(nav_items), 0, "Setup failed: explicit navigation item found!"
+        )
+
         # 7. Run Parser
         parser = get_book_parser(self.epub_path)
         parser.process_content()
         chapters = parser.get_chapters()
-        
+
         # 8. Assertions
         # Should have found the nav via content scanning
         chapter_titles = [c[1] for c in chapters]
         self.assertIn("Chapter 1", chapter_titles)
-        
+
         # Also verify we hit the "html" type in identification
         # We can't easily check private variables, but success implies it worked.
-        
+
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/test_epub_html_nav_parsing.py b/tests/test_epub_html_nav_parsing.py
index 7c255d8..5fea141 100644
--- a/tests/test_epub_html_nav_parsing.py
+++ b/tests/test_epub_html_nav_parsing.py
@@ -5,10 +5,11 @@ import sys
 from ebooklib import epub
 
 # Ensure import path
-sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
 from abogen.book_parser import get_book_parser
 
+
 class TestEpubHtmlNavParsing(unittest.TestCase):
     """
     Tests for EPUB 3 HTML5 Navigation Document parsing logic (_parse_html_nav_li).
@@ -32,12 +33,12 @@ class TestEpubHtmlNavParsing(unittest.TestCase):
         book = epub.EpubBook()
         book.set_identifier("navtest123")
         book.set_title("Nav Test Book")
-        
+
         # Add some content files
         c1 = epub.EpubHtml(title="Chapter 1", file_name="chap1.xhtml", lang="en")
         c1.content = "<h1>Chapter 1</h1><p>Text 1</p>"
         book.add_item(c1)
-        
+
         c2 = epub.EpubHtml(title="Chapter 2", file_name="chap2.xhtml", lang="en")
         c2.content = "<h1>Chapter 2</h1><p>Text 2</p>"
         book.add_item(c2)
@@ -47,29 +48,29 @@ class TestEpubHtmlNavParsing(unittest.TestCase):
         nav = epub.EpubHtml(title="Nav", file_name="nav.xhtml")
         nav.content = nav_html_content
         book.add_item(nav)
-        
+
         # We must set spine manually
         book.spine = [nav, c1, c2]
-        
+
         epub.write_epub(self.epub_path, book)
-        
-        # Patch the OPF to remove toc="ncx" default which causes crash 
+
+        # Patch the OPF to remove toc="ncx" default which causes crash
         # because we intentionally excluded the legacy NCX file.
         import zipfile
-        
-        with zipfile.ZipFile(self.epub_path, 'r') as zin:
-            opf_content = zin.read('EPUB/content.opf').decode('utf-8')
-            opf_content = opf_content.replace('toc="ncx"', '')
-            
+
+        with zipfile.ZipFile(self.epub_path, "r") as zin:
+            opf_content = zin.read("EPUB/content.opf").decode("utf-8")
+            opf_content = opf_content.replace('toc="ncx"', "")
+
             # Repack
             TEMP_EPUB = self.epub_path + ".temp"
-            with zipfile.ZipFile(TEMP_EPUB, 'w') as zout:
+            with zipfile.ZipFile(TEMP_EPUB, "w") as zout:
                 for item in zin.infolist():
-                    if item.filename == 'EPUB/content.opf':
+                    if item.filename == "EPUB/content.opf":
                         zout.writestr(item, opf_content)
                     else:
                         zout.writestr(item, zin.read(item.filename))
-        
+
         shutil.move(TEMP_EPUB, self.epub_path)
 
     def test_basic_html_nav_parsing(self):
@@ -86,14 +87,14 @@ class TestEpubHtmlNavParsing(unittest.TestCase):
         </nav>
         """
         self._create_epub_with_custom_nav(nav_html)
-        
+
         parser = get_book_parser(self.epub_path)
         parser.process_content()
         chapters = parser.get_chapters()
-        
+
         # Filter out "Nav" or "Introduction" prefix content found from the Nav file itself
         chapters = [c for c in chapters if "Chapter" in c[1] or "Section" in c[1]]
-        
+
         self.assertEqual(len(chapters), 2)
         self.assertEqual(chapters[0][1], "Chapter 1")
         self.assertEqual(chapters[1][1], "Chapter 2")
@@ -116,11 +117,11 @@ class TestEpubHtmlNavParsing(unittest.TestCase):
         """
         # Note: In this test setup, chap2 is serving as "Section 1.1" effectively
         self._create_epub_with_custom_nav(nav_html)
-        
+
         parser = get_book_parser(self.epub_path)
         parser.process_content()
         chapters = parser.get_chapters()
-        
+
         ids = [c[1] for c in chapters]
         self.assertIn("Chapter 1", ids)
         self.assertIn("Section 1.1", ids)
@@ -143,25 +144,26 @@ class TestEpubHtmlNavParsing(unittest.TestCase):
         </nav>
         """
         self._create_epub_with_custom_nav(nav_html)
-        
+
         parser = get_book_parser(self.epub_path)
         parser.process_content()
-        
+
         chapters = parser.get_chapters()
         chapter_titles = [c[1] for c in chapters]
-        
+
         self.assertIn("Chapter 1", chapter_titles)
-        self.assertNotIn("Part I", chapter_titles) 
-        
+        self.assertNotIn("Part I", chapter_titles)
+
         # Check internal structure
         # Find the node named "Part I" in the processed structure
-        root_node = next(node for node in parser.processed_nav_structure if node['title'] == "Part I")
-        
-        self.assertEqual(root_node['title'], "Part I")
-        self.assertFalse(root_node['has_content'])
-        self.assertEqual(len(root_node['children']), 1)
-        self.assertEqual(root_node['children'][0]['title'], "Chapter 1")
+        root_node = next(
+            node for node in parser.processed_nav_structure if node["title"] == "Part I"
+        )
 
+        self.assertEqual(root_node["title"], "Part I")
+        self.assertFalse(root_node["has_content"])
+        self.assertEqual(len(root_node["children"]), 1)
+        self.assertEqual(root_node["children"][0]["title"], "Chapter 1")
 
     def test_identify_nav_item(self):
         """Test the _identify_nav_item method specifically."""
@@ -175,10 +177,11 @@ class TestEpubHtmlNavParsing(unittest.TestCase):
         # But here we can call load directly if needed, or rely on normal flow up until navigation
         parser.load()
         nav_item, nav_type = parser._identify_nav_item()
-        
+
         self.assertEqual(nav_type, "html")
         self.assertIsNotNone(nav_item)
         self.assertTrue("nav.xhtml" in nav_item.get_name())
 
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/test_epub_missing_file_error_handling.py b/tests/test_epub_missing_file_error_handling.py
index 8005092..18c69ca 100644
--- a/tests/test_epub_missing_file_error_handling.py
+++ b/tests/test_epub_missing_file_error_handling.py
@@ -7,10 +7,11 @@ import logging
 from ebooklib import epub
 
 # Ensure import path
-sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
 from abogen.book_parser import get_book_parser
 
+
 class TestEpubMissingFileErrorHandling(unittest.TestCase):
     """
     Tests for robust error handling and recovery in the book parser.
@@ -22,8 +23,8 @@ class TestEpubMissingFileErrorHandling(unittest.TestCase):
             shutil.rmtree(self.test_dir)
         os.makedirs(self.test_dir)
         self.broken_epub_path = os.path.join(self.test_dir, "missing_file.epub")
-        
-        # Suppress logging during tests to keep output clean, 
+
+        # Suppress logging during tests to keep output clean,
         # or capture it if we want to assert on warnings.
         # For now, we just let it be or set level to ERROR.
         logging.getLogger().setLevel(logging.ERROR)
@@ -39,27 +40,27 @@ class TestEpubMissingFileErrorHandling(unittest.TestCase):
         book = epub.EpubBook()
         book.set_identifier("broken123")
         book.set_title("Broken Book")
-        
+
         # 1. Add a valid chapter
         c1 = epub.EpubHtml(title="Chapter 1", file_name="chap1.xhtml", lang="en")
         c1.content = "<h1>Chapter 1</h1><p>Survivable content.</p>"
         book.add_item(c1)
-        
+
         # 2. Add a 'ghost' chapter that we will delete later
         c2 = epub.EpubHtml(title="Ghost Chapter", file_name="ghost.xhtml", lang="en")
         c2.content = "<h1>Ghost</h1><p>I will disappear.</p>"
         book.add_item(c2)
-        
+
         book.spine = ["nav", c1, c2]
         book.add_item(epub.EpubNcx())
         book.add_item(epub.EpubNav())
-        
+
         temp_path = os.path.join(self.test_dir, "temp.epub")
         epub.write_epub(temp_path, book)
-        
+
         # 3. Physically remove 'ghost.xhtml' from the ZIP
-        with zipfile.ZipFile(temp_path, 'r') as zin:
-            with zipfile.ZipFile(self.broken_epub_path, 'w') as zout:
+        with zipfile.ZipFile(temp_path, "r") as zin:
+            with zipfile.ZipFile(self.broken_epub_path, "w") as zout:
                 for item in zin.infolist():
                     # Copy everything EXCEPT the ghost file
                     # Note: ebooklib might put files in OEPS/ or EPUB/ folders depending on version,
@@ -73,14 +74,14 @@ class TestEpubMissingFileErrorHandling(unittest.TestCase):
         Should log a warning instead of raising KeyError.
         """
         self._create_broken_epub()
-        
+
         try:
             parser = get_book_parser(self.broken_epub_path)
             parser.process_content()
-            
+
             # 1. Ensure process didn't crash
             self.assertTrue(True, "Parser should not crash on missing file")
-            
+
             # 2. Ensure valid content was extracted
             # Identify the ID for chap1.xhtml (usually file path based)
             # Since IDs can vary, we check if ANY content contains our known string
@@ -90,11 +91,12 @@ class TestEpubMissingFileErrorHandling(unittest.TestCase):
                     chap1_found = True
                     break
             self.assertTrue(chap1_found, "The valid chapter should still be processed")
-            
+
         except KeyError:
             self.fail("Parser raised KeyError instead of handling the missing file!")
         except Exception as e:
             self.fail(f"Parser raised unexpected exception: {e}")
 
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/test_epub_ncx_parsing.py b/tests/test_epub_ncx_parsing.py
index bf24710..313d785 100644
--- a/tests/test_epub_ncx_parsing.py
+++ b/tests/test_epub_ncx_parsing.py
@@ -5,13 +5,14 @@ import sys
 from ebooklib import epub
 
 # Ensure we can import the module
-sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
 from abogen.book_parser import get_book_parser, EpubParser
 
+
 class TestEpubNcxParsing(unittest.TestCase):
     """
-    Focused tests for NCX navigation scenarios, ensuring legacy/compatibility 
+    Focused tests for NCX navigation scenarios, ensuring legacy/compatibility
     modes work when HTML5 Navigation is missing.
     """
 
@@ -50,9 +51,9 @@ class TestEpubNcxParsing(unittest.TestCase):
         # Add default NCX and generic spine
         book.add_item(epub.EpubNcx())
         # IMPORTANT: Do NOT add EpubNav() here, that's what we are testing!
-        
+
         book.spine = ["nav"] + epub_chapters
-        
+
         epub.write_epub(self.ncx_only_epub_path, book)
 
     def test_ncx_only_parsing(self):
@@ -63,28 +64,28 @@ class TestEpubNcxParsing(unittest.TestCase):
         # 1. Setup Data
         chapters_data = [
             ("Chapter 1", "This is the first chapter."),
-            ("Chapter 2", "This is the second chapter.")
+            ("Chapter 2", "This is the second chapter."),
         ]
         self._create_ncx_only_epub(chapters_data)
 
         # 2. Run Parser
         parser = get_book_parser(self.ncx_only_epub_path)
         parser.process_content()
-        
+
         # 3. Verify Breakdown
         # We expect detailed breakdown based on NCX
         chapters = parser.get_chapters()
-        
+
         # Should find exactly 2 chapters based on the Toc
         self.assertEqual(len(chapters), 2, "Should have 2 chapters extracted from NCX")
-        
+
         # Check Titles and Sequence
         self.assertEqual(chapters[0][1], "Chapter 1")
         self.assertEqual(chapters[1][1], "Chapter 2")
-        
+
         # Verify content was extracted
         # Note: 'src' in chapters usually points to file_name if no fragments
-        id_1 = chapters[0][0] 
+        id_1 = chapters[0][0]
         self.assertIn("This is the first chapter", parser.content_texts[id_1])
 
     def test_nested_ncx_parsing(self):
@@ -94,7 +95,7 @@ class TestEpubNcxParsing(unittest.TestCase):
         book = epub.EpubBook()
         book.set_identifier("nested_ncx")
         book.set_title("Nested NCX")
-        
+
         # Create one big file with sections
         c1 = epub.EpubHtml(title="Main Chapter", file_name="main.xhtml", lang="en")
         c1.content = """
@@ -108,33 +109,32 @@ class TestEpubNcxParsing(unittest.TestCase):
         # Manually construct nested TOC because ebooklib's default helpers are simple
         # EbookLib automatically builds NCX from book.toc
         # Nested tuple structure: (Section, (Subsection, Sub-subsection))
-        
+
         # We need to link to Fragments for this to really test nested NCX pointing to same file
         # EbookLib Link object: epub.Link(href, title, uid)
-        
+
         link_root = epub.Link("main.xhtml#intro", "Introduction", "intro")
         link_sect = epub.Link("main.xhtml#sect1", "Section 1", "sect1")
-        
+
         # Structure: Intro -> Section 1 (as child)
-        book.toc = (
-            (link_root, (link_sect, )),
-        )
-        
+        book.toc = ((link_root, (link_sect,)),)
+
         book.add_item(epub.EpubNcx())
         book.spine = ["nav", c1]
-        
+
         epub.write_epub(self.ncx_only_epub_path, book)
-        
+
         # Parse
         parser = get_book_parser(self.ncx_only_epub_path)
         parser.process_content()
-        
+
         chapters = parser.get_chapters()
-        
+
         # Depending on how the parser flattens, we should see both entries
         titles = [node[1] for node in chapters]
         self.assertIn("Introduction", titles)
         self.assertIn("Section 1", titles)
 
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/test_epub_standard_nav.py b/tests/test_epub_standard_nav.py
index d916f1e..b4aaf39 100644
--- a/tests/test_epub_standard_nav.py
+++ b/tests/test_epub_standard_nav.py
@@ -7,10 +7,11 @@ import ebooklib
 from unittest.mock import MagicMock
 
 # Ensure import path
-sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
 from abogen.book_parser import get_book_parser
 
+
 class TestEpubStandardNav(unittest.TestCase):
     """
     Tests for the standard ITEM_NAVIGATION discovery in _identify_nav_item.
@@ -33,38 +34,39 @@ class TestEpubStandardNav(unittest.TestCase):
         book = epub.EpubBook()
         book.set_identifier("stdnav123")
         book.set_title("Standard Nav Test")
-        
+
         c1 = epub.EpubHtml(title="Chapter 1", file_name="chap1.xhtml", lang="en")
         c1.content = "<h1>Chapter 1</h1><p>Text 1</p>"
         book.add_item(c1)
-        
+
         # Use Standard EpubNav
         nav = epub.EpubNav()
         book.add_item(nav)
         book.spine = [nav, c1]
-        
+
         epub.write_epub(self.epub_path, book)
-        
+
         # "Zip Surgery" Patch:
         # ebooklib unconditionally adds `toc="ncx"` to the spine, even for EPUB 3 files that purely use HTML Nav.
         # This creates a dangling reference to a non-existent "ncx" item, causing ebooklib to crash on read.
         # We manually remove this attribute to ensure the test EPUB is valid and readable.
         # TODO - find real world examples of EPUB 3 files that use HTML Nav
         import zipfile
+
         patched = False
-        with zipfile.ZipFile(self.epub_path, 'r') as zin:
-            opf_content = zin.read('EPUB/content.opf').decode('utf-8')
+        with zipfile.ZipFile(self.epub_path, "r") as zin:
+            opf_content = zin.read("EPUB/content.opf").decode("utf-8")
             if 'toc="ncx"' in opf_content:
-                opf_content = opf_content.replace('toc="ncx"', '')
+                opf_content = opf_content.replace('toc="ncx"', "")
                 patched = True
                 TEMP_EPUB = self.epub_path + ".temp"
-                with zipfile.ZipFile(TEMP_EPUB, 'w') as zout:
+                with zipfile.ZipFile(TEMP_EPUB, "w") as zout:
                     for item in zin.infolist():
-                        if item.filename == 'EPUB/content.opf':
+                        if item.filename == "EPUB/content.opf":
                             zout.writestr(item, opf_content)
                         else:
                             zout.writestr(item, zin.read(item.filename))
-        
+
         if patched:
             shutil.move(TEMP_EPUB, self.epub_path)
 
@@ -78,18 +80,18 @@ class TestEpubStandardNav(unittest.TestCase):
         This exercises the first branch of _identify_nav_item.
         """
         parser = self._create_and_load_epub()
-        
+
         # Inject an item that mocks the ITEM_NAVIGATION type behavior
         # (This simulates a library/parser that correctly types the item as 4)
         mock_nav = MagicMock()
         mock_nav.get_name.return_value = "nav.xhtml"
         mock_nav.get_type.return_value = ebooklib.ITEM_NAVIGATION
-        
+
         # We append this mock to the book items to ensure get_items_of_type(ITEM_NAVIGATION) finds it
         parser.book.items.append(mock_nav)
-        
+
         nav_item, nav_type = parser._identify_nav_item()
-        
+
         self.assertEqual(nav_type, "html")
         self.assertEqual(nav_item.get_name(), "nav.xhtml")
         # Verify we are getting the object we expect (implied by success)
@@ -100,31 +102,32 @@ class TestEpubStandardNav(unittest.TestCase):
         This is the standard EPUB 3 behavior and exercises the fallback branch.
         """
         parser = self._create_and_load_epub()
-        
+
         # Locate the generic 'nav' item loaded by ebooklib
         original_nav = parser.book.get_item_with_id("nav")
         self.assertIsNotNone(original_nav)
-        
+
         # "Fix" the object to match what we expect from a correct EPUB 3 read:
         # It should have properties=['nav'].
         # We use a real EpubNav object to ensure structural correctness.
         proper_nav = epub.EpubNav(uid=original_nav.id, file_name=original_nav.file_name)
         proper_nav.content = original_nav.content
-        proper_nav.properties = ['nav']
-        
+        proper_nav.properties = ["nav"]
+
         # Swap it into the book items list
         try:
             idx = parser.book.items.index(original_nav)
             parser.book.items[idx] = proper_nav
         except ValueError:
             self.fail("Could not find original nav item to swap")
-            
+
         nav_item, nav_type = parser._identify_nav_item()
-        
+
         self.assertEqual(nav_type, "html")
         self.assertEqual(nav_item.get_name(), "nav.xhtml")
         # Check that we actually found the one with properties
-        self.assertEqual(getattr(nav_item, 'properties', []), ['nav'])
+        self.assertEqual(getattr(nav_item, "properties", []), ["nav"])
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/test_output_paths.py b/tests/test_output_paths.py
index a1d14a8..77e8992 100644
--- a/tests/test_output_paths.py
+++ b/tests/test_output_paths.py
@@ -30,16 +30,22 @@ def _sample_job(tmp_path: Path) -> Job:
     )
 
 
-def test_prepare_project_layout_uses_timestamped_folder(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+def test_prepare_project_layout_uses_timestamped_folder(
+    monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+) -> None:
     job = _sample_job(tmp_path)
     monkeypatch.setattr(
         "abogen.webui.conversion_runner._output_timestamp_token",
         lambda: "20250101-120000",
     )
 
-    project_root, audio_dir, subtitle_dir, metadata_dir = _prepare_project_layout(job, tmp_path)
+    project_root, audio_dir, subtitle_dir, metadata_dir = _prepare_project_layout(
+        job, tmp_path
+    )
 
-    assert project_root.name.startswith("20250101-120000_Sample_Title"), project_root.name
+    assert project_root.name.startswith(
+        "20250101-120000_Sample_Title"
+    ), project_root.name
     assert audio_dir == project_root
     assert subtitle_dir == project_root
     assert metadata_dir is None
@@ -48,7 +54,9 @@ def test_prepare_project_layout_uses_timestamped_folder(monkeypatch: pytest.Monk
     assert output_path == project_root / "Sample_Title.mp3"
 
 
-def test_prepare_project_layout_creates_project_subdirs(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+def test_prepare_project_layout_creates_project_subdirs(
+    monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+) -> None:
     job = _sample_job(tmp_path)
     job.save_as_project = True
     monkeypatch.setattr(
@@ -56,7 +64,9 @@ def test_prepare_project_layout_creates_project_subdirs(monkeypatch: pytest.Monk
         lambda: "20250101-120500",
     )
 
-    project_root, audio_dir, subtitle_dir, metadata_dir = _prepare_project_layout(job, tmp_path)
+    project_root, audio_dir, subtitle_dir, metadata_dir = _prepare_project_layout(
+        job, tmp_path
+    )
 
     assert audio_dir == project_root / "audio"
     assert subtitle_dir == project_root / "subtitles"
diff --git a/tests/test_prepare_form.py b/tests/test_prepare_form.py
index 4ea05eb..9456d0f 100644
--- a/tests/test_prepare_form.py
+++ b/tests/test_prepare_form.py
@@ -102,7 +102,9 @@ def test_resolve_voice_setting_handles_profile_reference():
         }
     }
 
-    voice, profile_name, language = resolve_voice_setting("profile:Blend", profiles=profiles)
+    voice, profile_name, language = resolve_voice_setting(
+        "profile:Blend", profiles=profiles
+    )
 
     assert voice == "af_nova*0.5+am_liam*0.5"
     assert profile_name == "Blend"
@@ -112,9 +114,11 @@ def test_resolve_voice_setting_handles_profile_reference():
 def test_apply_prepare_form_updates_closing_outro_flag():
     pending = _make_pending_job()
     pending.read_closing_outro = True
-    form = MultiDict({
-        "read_closing_outro": "false",
-    })
+    form = MultiDict(
+        {
+            "read_closing_outro": "false",
+        }
+    )
 
     apply_prepare_form(pending, form)
 
diff --git a/tests/test_preview_applies_manual_overrides.py b/tests/test_preview_applies_manual_overrides.py
index 76998c4..0f08512 100644
--- a/tests/test_preview_applies_manual_overrides.py
+++ b/tests/test_preview_applies_manual_overrides.py
@@ -13,7 +13,9 @@ def test_preview_applies_manual_override_before_normalization(monkeypatch):
         def normalize_for_pipeline(text):
             return text
 
-    monkeypatch.setitem(__import__("sys").modules, "abogen.kokoro_text_normalization", _Norm)
+    monkeypatch.setitem(
+        __import__("sys").modules, "abogen.kokoro_text_normalization", _Norm
+    )
 
     # And stub the kokoro pipeline path so generate_preview_audio won't proceed.
     # We'll instead validate by calling the override logic through generate_preview_audio
@@ -28,7 +30,11 @@ def test_preview_applies_manual_override_before_normalization(monkeypatch):
             captured["text"] = text
             return iter(())
 
-    monkeypatch.setitem(__import__("sys").modules, "abogen.tts_supertonic", type("M", (), {"SupertonicPipeline": DummyPipeline}))
+    monkeypatch.setitem(
+        __import__("sys").modules,
+        "abogen.tts_supertonic",
+        type("M", (), {"SupertonicPipeline": DummyPipeline}),
+    )
 
     try:
         preview.generate_preview_audio(
diff --git a/tests/test_regression_fixes.py b/tests/test_regression_fixes.py
index 7bf0396..babc2f8 100644
--- a/tests/test_regression_fixes.py
+++ b/tests/test_regression_fixes.py
@@ -1,16 +1,21 @@
 import pytest
 from unittest.mock import patch
-from abogen.kokoro_text_normalization import normalize_for_pipeline, DEFAULT_APOSTROPHE_CONFIG
+from abogen.kokoro_text_normalization import (
+    normalize_for_pipeline,
+    DEFAULT_APOSTROPHE_CONFIG,
+)
 from abogen.normalization_settings import build_apostrophe_config, _SETTINGS_DEFAULTS
 
+
 def normalize(text, overrides=None):
     settings = dict(_SETTINGS_DEFAULTS)
     if overrides:
         settings.update(overrides)
-    
+
     config = build_apostrophe_config(settings=settings, base=DEFAULT_APOSTROPHE_CONFIG)
     return normalize_for_pipeline(text, config=config, settings=settings)
 
+
 def test_year_pronunciation():
     # 1925 -> Nineteen Hundred Twenty Five
     normalized = normalize("1925")
@@ -24,6 +29,7 @@ def test_year_pronunciation():
     assert "twenty twenty" in normalized.lower()
     assert "five" in normalized.lower()
 
+
 def test_currency_pronunciation():
     # $1.00 -> One dollar (no zero cents)
     normalized = normalize("$1.00")
@@ -37,6 +43,7 @@ def test_currency_pronunciation():
     assert "one dollar" in normalized.lower()
     assert "five cents" in normalized.lower()
 
+
 def test_url_pronunciation():
     # https://www.amazon.com -> amazon dot com
     normalized = normalize("https://www.amazon.com")
@@ -50,6 +57,7 @@ def test_url_pronunciation():
     print(f"www.google.com -> {normalized}")
     assert "google dot com" in normalized.lower()
 
+
 def test_roman_numerals_world_war():
     # World War I -> World War One
     normalized = normalize("World War I")
@@ -61,6 +69,7 @@ def test_roman_numerals_world_war():
     print(f"World War II -> {normalized}")
     assert "world war two" in normalized.lower()
 
+
 def test_footnote_removal():
     # Bob is awesome1. -> Bob is awesome.
     normalized = normalize("Bob is awesome1.")
@@ -74,8 +83,10 @@ def test_footnote_removal():
     assert "citation needed." in normalized.lower()
     assert "[1]" not in normalized
 
+
 def test_manual_override_normalization():
     from abogen.entity_analysis import normalize_manual_override_token
+
     assert normalize_manual_override_token("The") == "the"
     assert normalize_manual_override_token("  A  ") == "a"
     assert normalize_manual_override_token("word") == "word"
diff --git a/tests/test_service.py b/tests/test_service.py
index 07c61f1..afa56c5 100644
--- a/tests/test_service.py
+++ b/tests/test_service.py
@@ -2,7 +2,13 @@ from __future__ import annotations
 
 import io
 import time
-from abogen.webui.service import Job, JobStatus, build_service, _JOB_LOGGER, build_audiobookshelf_metadata
+from abogen.webui.service import (
+    Job,
+    JobStatus,
+    build_service,
+    _JOB_LOGGER,
+    build_audiobookshelf_metadata,
+)
 
 
 def test_service_processes_job(tmp_path):
@@ -47,7 +53,11 @@ def test_service_processes_job(tmp_path):
     )
 
     deadline = time.time() + 5
-    while time.time() < deadline and job.status not in {JobStatus.COMPLETED, JobStatus.FAILED, JobStatus.CANCELLED}:
+    while time.time() < deadline and job.status not in {
+        JobStatus.COMPLETED,
+        JobStatus.FAILED,
+        JobStatus.CANCELLED,
+    }:
         time.sleep(0.05)
 
     service.shutdown()
@@ -287,4 +297,4 @@ def test_audiobookshelf_metadata_allows_decimal_sequence(tmp_path):
 
     metadata = build_audiobookshelf_metadata(job)
 
-    assert metadata["seriesSequence"] == "4.5"
\ No newline at end of file
+    assert metadata["seriesSequence"] == "4.5"
diff --git a/tests/test_speaker_analysis.py b/tests/test_speaker_analysis.py
index 88885a5..2b46085 100644
--- a/tests/test_speaker_analysis.py
+++ b/tests/test_speaker_analysis.py
@@ -24,9 +24,12 @@ def _chunk(text: str, idx: int) -> dict:
 
 def test_analyze_speakers_infers_gender_from_pronouns():
     chunks = [
-        _chunk("\"Greetings,\" said John. He adjusted his hat as he smiled.", 0),
-        _chunk("\"Hello,\" said Mary. She straightened her dress as she introduced herself.", 1),
-        _chunk("\"Nice to meet you,\" said Alex.", 2),
+        _chunk('"Greetings," said John. He adjusted his hat as he smiled.', 0),
+        _chunk(
+            '"Hello," said Mary. She straightened her dress as she introduced herself.',
+            1,
+        ),
+        _chunk('"Nice to meet you," said Alex.', 2),
     ]
 
     analysis = analyze_speakers(_chapters(), chunks, threshold=1, max_speakers=0)
@@ -63,8 +66,8 @@ def test_analyze_speakers_ignores_leading_stopwords():
 
 def test_analyze_speakers_applies_threshold_suppression():
     chunks = [
-        _chunk("\"Hello there,\" said Narrator.", 0),
-        _chunk("\"It is lying,\" said Green.", 1),
+        _chunk('"Hello there," said Narrator.', 0),
+        _chunk('"It is lying," said Green.', 1),
     ]
 
     analysis = analyze_speakers(_chapters(), chunks, threshold=3, max_speakers=0)
@@ -78,7 +81,7 @@ def test_analyze_speakers_applies_threshold_suppression():
 def test_sample_excerpt_includes_context_paragraphs():
     chunks = [
         _chunk("The hallway was quiet as footsteps approached.", 0),
-        _chunk('\"Open the door,\" said John as he reached for the handle.', 1),
+        _chunk('"Open the door," said John as he reached for the handle.', 1),
         _chunk("Mary watched him closely, unsure of his intent.", 2),
     ]
 
@@ -89,5 +92,5 @@ def test_sample_excerpt_includes_context_paragraphs():
     assert john.sample_quotes, "Expected John to have at least one sample quote"
     excerpt = john.sample_quotes[0]["excerpt"]
     assert "The hallway was quiet" in excerpt
-    assert "\"Open the door,\" said John" in excerpt
+    assert '"Open the door," said John' in excerpt
     assert "Mary watched him closely" in excerpt
diff --git a/tests/test_text_extractor.py b/tests/test_text_extractor.py
index f63b67f..cf7db58 100644
--- a/tests/test_text_extractor.py
+++ b/tests/test_text_extractor.py
@@ -6,7 +6,9 @@ from abogen.text_extractor import extract_from_path
 from abogen.utils import calculate_text_length
 
 
-ASSET = Path("test_assets/alexandre-dumas_the-count-of-monte-cristo_chapman-and-hall.epub")
+ASSET = Path(
+    "test_assets/alexandre-dumas_the-count-of-monte-cristo_chapman-and-hall.epub"
+)
 
 
 def test_epub_character_counts_align_with_calculated_total():
@@ -37,8 +39,12 @@ def test_epub_series_metadata_extracted_from_opf_meta(tmp_path):
     book.add_author("Example Author")
 
     # Calibre-style series metadata
-    book.add_metadata("OPF", "meta", "", {"name": "calibre:series", "content": "Example Saga"})
-    book.add_metadata("OPF", "meta", "", {"name": "calibre:series_index", "content": "2"})
+    book.add_metadata(
+        "OPF", "meta", "", {"name": "calibre:series", "content": "Example Saga"}
+    )
+    book.add_metadata(
+        "OPF", "meta", "", {"name": "calibre:series_index", "content": "2"}
+    )
 
     chapter = epub.EpubHtml(title="Chapter 1", file_name="chap_01.xhtml", lang="en")
     chapter.content = "<h1>Chapter 1</h1><p>Hello</p>"
diff --git a/tests/test_text_normalization.py b/tests/test_text_normalization.py
index 156fccf..4680017 100644
--- a/tests/test_text_normalization.py
+++ b/tests/test_text_normalization.py
@@ -16,14 +16,22 @@ from abogen.normalization_settings import (
 from abogen.spacy_contraction_resolver import resolve_ambiguous_contractions
 
 
-SPACY_RESOLVER_AVAILABLE = bool(resolve_ambiguous_contractions("It's been a long time."))
+SPACY_RESOLVER_AVAILABLE = bool(
+    resolve_ambiguous_contractions("It's been a long time.")
+)
 
 
-def _normalize_text(text: str, *, normalization_overrides: dict[str, object] | None = None) -> str:
+def _normalize_text(
+    text: str, *, normalization_overrides: dict[str, object] | None = None
+) -> str:
     runtime_settings = get_runtime_settings()
     if normalization_overrides:
-        runtime_settings = apply_normalization_overrides(runtime_settings, normalization_overrides)
-    config = build_apostrophe_config(settings=runtime_settings, base=DEFAULT_APOSTROPHE_CONFIG)
+        runtime_settings = apply_normalization_overrides(
+            runtime_settings, normalization_overrides
+        )
+    config = build_apostrophe_config(
+        settings=runtime_settings, base=DEFAULT_APOSTROPHE_CONFIG
+    )
     return normalize_for_pipeline(text, config=config, settings=runtime_settings)
 
 
@@ -202,7 +210,9 @@ def test_contractions_can_be_kept_when_override_disabled() -> None:
 def test_sibilant_possessives_remain_when_marking_disabled() -> None:
     normalized = _normalize_text(
         "The boss's chair wobbled.",
-        normalization_overrides={"normalization_apostrophes_sibilant_possessives": False},
+        normalization_overrides={
+            "normalization_apostrophes_sibilant_possessives": False
+        },
     )
     assert "boss's" in normalized
     assert "boss iz" not in normalized.lower()
@@ -276,10 +286,13 @@ def test_spacy_disambiguates_she_would() -> None:
 
 @pytest.mark.skipif(not SPACY_RESOLVER_AVAILABLE, reason="spaCy model unavailable")
 def test_sample_sentence_handles_complex_contractions() -> None:
-    sample = "I've heard the captain'll arrive by dusk, but they'd said the same yesterday."
+    sample = (
+        "I've heard the captain'll arrive by dusk, but they'd said the same yesterday."
+    )
     normalized = _normalize_text(sample)
     assert (
-        "I have heard the captain will arrive by dusk, but they had said the same yesterday." == normalized
+        "I have heard the captain will arrive by dusk, but they had said the same yesterday."
+        == normalized
     )
 
 
@@ -316,9 +329,12 @@ def mock_settings():
         "normalization_footnotes": True,
         "normalization_numbers_year_style": "american",
     }
-    with patch("tests.test_text_normalization.get_runtime_settings", return_value=defaults):
+    with patch(
+        "tests.test_text_normalization.get_runtime_settings", return_value=defaults
+    ):
         yield
 
+
 def test_currency_magnitude():
     cases = [
         ("$2 million", "two million dollars"),
@@ -331,13 +347,15 @@ def test_currency_magnitude():
         ("$2.50", "two dollars, fifty cents"),
         ("$100", "one hundred dollars"),
     ]
-    
+
     settings = {
         "normalization_numbers": True,
         "normalization_currency": True,
-        "normalization_apostrophe_mode": "spacy"
+        "normalization_apostrophe_mode": "spacy",
     }
-    
+
     for input_text, expected in cases:
         normalized = _normalize_text(input_text, normalization_overrides=settings)
-        assert expected.lower() in normalized.lower(), f"Failed for {input_text}: got '{normalized}'"
+        assert (
+            expected.lower() in normalized.lower()
+        ), f"Failed for {input_text}: got '{normalized}'"
diff --git a/tests/test_voice_cache.py b/tests/test_voice_cache.py
index b0aa2ca..c428b3a 100644
--- a/tests/test_voice_cache.py
+++ b/tests/test_voice_cache.py
@@ -4,7 +4,11 @@ from typing import cast
 import pytest
 
 from abogen.constants import VOICES_INTERNAL
-from abogen.voice_cache import LocalEntryNotFoundError, _CACHED_VOICES, ensure_voice_assets
+from abogen.voice_cache import (
+    LocalEntryNotFoundError,
+    _CACHED_VOICES,
+    ensure_voice_assets,
+)
 from abogen.webui.conversion_runner import _collect_required_voice_ids
 from abogen.webui.service import Job