diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..e21e65c
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,6 @@
+# Copy this file to `.env` and customize the paths to match your environment.
+# Relative paths are resolved from the repository root when running locally.
+
+ABOGEN_SETTINGS_DIR=./config
+ABOGEN_TEMP_DIR=./storage/tmp
+ABOGEN_OUTPUT_DIR=./storage/output
diff --git a/.gitignore b/.gitignore
index c99cf9f..f60d968 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,6 +19,7 @@ __pycache__/
 env/
 venv/
 .env/
+.env
 .venv/
 test/
 
@@ -30,6 +31,8 @@ python_embedded/
 
 # abogen
 *config.json
+config/
+storage/
 build/
 dist/
 .old/
diff --git a/README.md b/README.md
index bc3c41a..d288fab 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,9 @@ Browse to http://localhost:8808. Uploaded source files are stored in `/data/uplo
 | `ABOGEN_DEBUG` | `false` | Enable Flask debug mode |
 | `ABOGEN_UPLOAD_ROOT` | `/data/uploads` | Directory where uploaded files are stored |
 | `ABOGEN_OUTPUT_ROOT` | `/data/outputs` | Directory for generated audio and subtitles |
+| `ABOGEN_TEMP_DIR` | Platform cache dir (e.g. `~/.cache/abogen`) | Override the cache/temp directory |
+| `ABOGEN_OUTPUT_DIR` | Same as `ABOGEN_OUTPUT_ROOT` | Override the rendered output directory |
+| `ABOGEN_SETTINGS_DIR` | Platform config dir (e.g. `~/.config/abogen`) | Override where JSON settings (profiles, config) are stored |
 
 Set any of these with `-e VAR=value` when starting the container.
 
@@ -111,9 +114,14 @@ More automation hooks are planned; contributions are very welcome if you need ad
 Most behaviour is controlled through the UI, but a few environment variables are helpful for automation:
 - `ABOGEN_SECRET_KEY` – provide your own random secret when deploying across multiple replicas.
 - `ABOGEN_DEBUG` – set to `true` for verbose Flask error output.
+- `ABOGEN_SETTINGS_DIR` – change where Abogen stores its JSON settings/configuration files.
+- `ABOGEN_TEMP_DIR` – change where temporary uploads and cache files are stored.
+- `ABOGEN_OUTPUT_DIR` – change where rendered audio/subtitles are written.
 
 If unset, Abogen picks sensible defaults suitable for local usage.
 
+You can also create a `.env` file in the project root (see `.env.example`) to configure these paths when running locally. The application loads `.env` automatically on startup.
+
 ## Development workflow
 ```bash
 git clone https://github.com/denizsafak/abogen.git
diff --git a/abogen/utils.py b/abogen/utils.py
index 0435d77..94144af 100644
--- a/abogen/utils.py
+++ b/abogen/utils.py
@@ -1,13 +1,19 @@
-import os
-import sys
 import json
-import warnings
+import os
 import platform
+import re
 import shutil
 import subprocess
-import re
+import sys
+import warnings
 from threading import Thread
 
+from functools import lru_cache
+
+from dotenv import load_dotenv
+
+load_dotenv()
+
 warnings.filterwarnings("ignore")
 
 
@@ -82,40 +88,69 @@ def get_version():
 
 
 # Define config path
-def get_user_config_path():
+def ensure_directory(path):
+    resolved = os.path.abspath(os.path.expanduser(str(path)))
+    os.makedirs(resolved, exist_ok=True)
+    return resolved
+
+
+@lru_cache(maxsize=1)
+def get_user_settings_dir():
+    override = os.environ.get("ABOGEN_SETTINGS_DIR")
+    if override:
+        return ensure_directory(override)
+
     from platformdirs import user_config_dir
 
-    # TODO Config directory is changed for Linux and MacOS. But if old config exists, it will be used.
-    # On non‑Windows, prefer ~/.config/abogen if it already exists
     if platform.system() != "Windows":
-        custom_dir = os.path.join(os.path.expanduser("~"), ".config", "abogen")
-        if os.path.exists(custom_dir):
-            config_dir = custom_dir
-        else:
-            config_dir = user_config_dir(
-                "abogen", appauthor=False, roaming=True, ensure_exists=True
-            )
-    else:
-        # Windows and fallback case
-        config_dir = user_config_dir(
-            "abogen", appauthor=False, roaming=True, ensure_exists=True
-        )
+        legacy_dir = os.path.join(os.path.expanduser("~"), ".config", "abogen")
+        if os.path.exists(legacy_dir):
+            return ensure_directory(legacy_dir)
 
-    return os.path.join(config_dir, "config.json")
+    config_dir = user_config_dir("abogen", appauthor=False, roaming=True, ensure_exists=True)
+    return ensure_directory(config_dir)
+
+
+def get_user_config_path():
+    return os.path.join(get_user_settings_dir(), "config.json")
 
 
 # Define cache path
-def get_user_cache_path(folder=None):
+@lru_cache(maxsize=1)
+def get_user_cache_root():
+    override = os.environ.get("ABOGEN_TEMP_DIR")
+    if override:
+        return ensure_directory(override)
+
     from platformdirs import user_cache_dir
 
-    cache_dir = user_cache_dir(
-        "abogen", appauthor=False, opinion=True, ensure_exists=True
-    )
+    cache_dir = user_cache_dir("abogen", appauthor=False, opinion=True, ensure_exists=True)
+    return ensure_directory(cache_dir)
+
+
+def get_user_cache_path(folder=None):
+    base = get_user_cache_root()
     if folder:
-        cache_dir = os.path.join(cache_dir, folder)
-        # Ensure the directory exists
-        os.makedirs(cache_dir, exist_ok=True)
-    return cache_dir
+        return ensure_directory(os.path.join(base, folder))
+    return base
+
+
+@lru_cache(maxsize=1)
+def get_user_output_root():
+    override = (
+        os.environ.get("ABOGEN_OUTPUT_DIR")
+        or os.environ.get("ABOGEN_OUTPUT_ROOT")
+    )
+    if override:
+        return ensure_directory(override)
+    return ensure_directory(os.path.join(get_user_cache_root(), "outputs"))
+
+
+def get_user_output_path(folder=None):
+    base = get_user_output_root()
+    if folder:
+        return ensure_directory(os.path.join(base, folder))
+    return base
 
 
 _sleep_procs = {"Darwin": None, "Linux": None}  # Store sleep prevention processes
diff --git a/abogen/web/app.py b/abogen/web/app.py
index e385fb4..0a4923e 100644
--- a/abogen/web/app.py
+++ b/abogen/web/app.py
@@ -7,7 +7,7 @@ from typing import Any, Optional
 
 from flask import Flask
 
-from abogen.utils import get_user_cache_path
+from abogen.utils import get_user_cache_path, get_user_output_path
 
 from .conversion_runner import run_conversion_job
 from .service import build_service
@@ -17,13 +17,15 @@ def _default_dirs() -> tuple[Path, Path]:
     uploads_override = os.environ.get("ABOGEN_UPLOAD_ROOT")
     outputs_override = os.environ.get("ABOGEN_OUTPUT_ROOT")
 
-    if uploads_override and outputs_override:
-        uploads = Path(uploads_override)
-        outputs = Path(outputs_override)
+    if uploads_override:
+        uploads = Path(os.path.expanduser(uploads_override)).resolve()
     else:
-        base = Path(get_user_cache_path("web"))
-        uploads = base / "uploads"
-        outputs = base / "outputs"
+        uploads = Path(get_user_cache_path("web/uploads"))
+
+    if outputs_override:
+        outputs = Path(os.path.expanduser(outputs_override)).resolve()
+    else:
+        outputs = Path(get_user_output_path("web"))
 
     uploads.mkdir(parents=True, exist_ok=True)
     outputs.mkdir(parents=True, exist_ok=True)
diff --git a/abogen/web/static/styles.css b/abogen/web/static/styles.css
index 612a769..62b3123 100644
--- a/abogen/web/static/styles.css
+++ b/abogen/web/static/styles.css
@@ -33,6 +33,9 @@ body {
   display: flex;
   align-items: center;
   justify-content: space-between;
+  position: sticky;
+  top: 0;
+  z-index: 100;
 }
 
 .brand {
@@ -397,8 +400,8 @@ progress.progress::-moz-progress-bar {
 
 .voice-mixer__layout {
   display: grid;
-  grid-template-columns: minmax(240px, 280px) 1fr;
-  gap: 2rem;
+  grid-template-columns: minmax(260px, 300px) 1fr;
+  gap: 2.25rem;
   align-items: start;
 }
 
@@ -511,8 +514,8 @@ progress.progress::-moz-progress-bar {
 
 .voice-editor__canvas {
   display: grid;
-  grid-template-columns: minmax(260px, 1fr) minmax(320px, 1fr);
-  gap: 1.5rem;
+  grid-template-columns: minmax(280px, 340px) minmax(320px, 1fr);
+  gap: 2rem;
   align-items: start;
 }
 
@@ -526,20 +529,67 @@ progress.progress::-moz-progress-bar {
 .voice-available__header,
 .voice-mix__header {
   display: flex;
-  align-items: center;
+  align-items: flex-end;
   justify-content: space-between;
-  gap: 0.75rem;
+  gap: 1rem;
+  flex-wrap: wrap;
+}
+
+.voice-available__title {
+  display: flex;
+  flex-direction: column;
+  gap: 0.25rem;
+}
+
+.voice-filter {
+  display: flex;
+  flex-direction: column;
+  gap: 0.35rem;
+  min-width: 180px;
+}
+
+.voice-filter label {
+  font-size: 0.75rem;
+  font-weight: 600;
+  letter-spacing: 0.04em;
+  text-transform: uppercase;
+  color: var(--muted);
+}
+
+.voice-filter select {
+  border-radius: 12px;
+  border: 1px solid rgba(148, 163, 184, 0.2);
+  background: rgba(15, 23, 42, 0.55);
+  padding: 0.55rem 0.75rem;
+  color: var(--text);
+  font-size: 0.95rem;
+}
+
+.voice-filter select:focus {
+  outline: none;
+  border-color: var(--accent);
+  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
 }
 
 .voice-available__list {
   display: grid;
   grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
-  gap: 0.75rem;
+  gap: 0.85rem;
   max-height: 55vh;
   overflow-y: auto;
   padding-right: 0.5rem;
 }
 
+.voice-available__empty {
+  margin: 0;
+  padding: 1.25rem 1rem;
+  text-align: center;
+  border: 1px dashed rgba(148, 163, 184, 0.25);
+  border-radius: 16px;
+  color: var(--muted);
+  background: rgba(15, 23, 42, 0.3);
+}
+
 .voice-available__card {
   border: 1px solid rgba(148, 163, 184, 0.18);
   border-radius: 18px;
@@ -609,8 +659,8 @@ progress.progress::-moz-progress-bar {
 .voice-mix__dropzone {
   border: 2px dashed rgba(148, 163, 184, 0.25);
   border-radius: 20px;
-  padding: 1.25rem;
-  min-height: 260px;
+  padding: 1.5rem;
+  min-height: 320px;
   background: rgba(15, 23, 42, 0.25);
   transition: border 0.2s ease, background 0.2s ease;
   display: flex;
@@ -640,7 +690,7 @@ progress.progress::-moz-progress-bar {
   border: 1px solid rgba(148, 163, 184, 0.2);
   border-radius: 18px;
   background: rgba(15, 23, 42, 0.4);
-  padding: 1rem 1.1rem;
+  padding: 1.1rem 1.2rem;
   display: flex;
   flex-direction: column;
   gap: 0.9rem;
@@ -803,4 +853,17 @@ progress.progress::-moz-progress-bar {
     max-height: none;
     padding-right: 0;
   }
+
+  .voice-available__header,
+  .voice-mix__header {
+    align-items: stretch;
+  }
+
+  .voice-filter {
+    width: 100%;
+  }
+
+  .voice-mix__dropzone {
+    min-height: 220px;
+  }
 }
diff --git a/abogen/web/static/voices.js b/abogen/web/static/voices.js
index 3a9bdba..352a77b 100644
--- a/abogen/web/static/voices.js
+++ b/abogen/web/static/voices.js
@@ -30,6 +30,7 @@ const setupVoiceMixer = () => {
   const selectedListEl = app.querySelector('[data-role="selected-voices"]');
   const dropzoneEl = app.querySelector('[data-role="dropzone"]');
   const emptyStateEl = app.querySelector('[data-role="mix-empty"]');
+  const voiceFilterSelect = app.querySelector('[data-role="voice-filter"]');
 
   if (!profileListEl || !availableListEl || !selectedListEl) {
     return;
@@ -55,6 +56,7 @@ const setupVoiceMixer = () => {
       language: "a",
       voices: new Map(),
     },
+    languageFilter: voiceFilterSelect ? voiceFilterSelect.value : "",
   };
 
   let statusTimeout = null;
@@ -211,14 +213,16 @@ const setupVoiceMixer = () => {
 
       const slider = document.createElement("input");
       slider.type = "range";
-      slider.min = "0";
+      slider.min = "5";
       slider.max = "100";
       slider.step = "1";
       slider.className = "mix-slider";
-      slider.value = String(Math.round(clamp(weight, 0, 1) * 100));
-      setSliderFill(slider, weight);
+      const normalizedWeight = clamp(weight, 0.05, 1);
+      slider.value = String(Math.round(normalizedWeight * 100));
+      setSliderFill(slider, normalizedWeight);
       slider.addEventListener("input", () => {
-        const value = clamp(Number(slider.value) / 100, 0, 1);
+        const value = clamp(Number(slider.value) / 100, 0.05, 1);
+        slider.value = String(Math.round(value * 100));
         state.draft.voices.set(voiceId, value);
         weightLabel.textContent = formatWeight(value);
         setSliderFill(slider, value);
@@ -244,7 +248,24 @@ const setupVoiceMixer = () => {
       .slice()
       .sort((a, b) => (a.display_name || a.id).localeCompare(b.display_name || b.id));
 
-    sortedVoices.forEach((voice) => {
+    const filteredVoices = sortedVoices.filter((voice) => {
+      const languageCode = voice.language || voice.id?.charAt(0) || "a";
+      return !state.languageFilter || state.languageFilter === languageCode;
+    });
+
+    if (!filteredVoices.length) {
+      const empty = document.createElement("p");
+      empty.className = "voice-available__empty";
+      const label = state.languageFilter
+        ? voiceLanguageLabel(state.languageFilter) || state.languageFilter.toUpperCase()
+        : "All voices";
+      empty.innerHTML = `No voices for <strong>${label}</strong> yet.`;
+      availableListEl.appendChild(empty);
+      updateAvailableState();
+      return;
+    }
+
+    filteredVoices.forEach((voice) => {
       if (!voice?.id) {
         return;
       }
@@ -309,6 +330,7 @@ const setupVoiceMixer = () => {
     });
 
     updateAvailableState();
+    availableListEl.scrollTop = 0;
   };
 
   const addVoiceToDraft = (voiceId, weight = 0.6) => {
@@ -445,7 +467,8 @@ const setupVoiceMixer = () => {
           const [voiceId, weight] = entry;
           const value = clamp(parseFloat(weight), 0, 1);
           if (!Number.isNaN(value) && value > 0) {
-            state.draft.voices.set(String(voiceId), value);
+            const normalized = clamp(value, 0.05, 1);
+            state.draft.voices.set(String(voiceId), normalized);
           }
         }
       });
@@ -697,6 +720,13 @@ const setupVoiceMixer = () => {
     });
   }
 
+  if (voiceFilterSelect) {
+    voiceFilterSelect.addEventListener("change", () => {
+      state.languageFilter = voiceFilterSelect.value;
+      renderAvailableVoices();
+    });
+  }
+
   if (nameInput) {
     nameInput.addEventListener("input", () => {
       state.draft.name = nameInput.value;
diff --git a/abogen/web/templates/voices.html b/abogen/web/templates/voices.html
index e9fb99e..8fb86bc 100644
--- a/abogen/web/templates/voices.html
+++ b/abogen/web/templates/voices.html
@@ -50,8 +50,19 @@
         <div class="voice-editor__canvas">
           <section class="voice-available">
             <header class="voice-available__header">
-              <h2>Available voices</h2>
-              <p class="tag">Drag into the mixer or click Add.</p>
+              <div class="voice-available__title">
+                <h2>Available voices</h2>
+                <p class="tag">Drag into the mixer or click Add.</p>
+              </div>
+              <div class="voice-filter">
+                <label for="voice-language-filter">Language</label>
+                <select id="voice-language-filter" data-role="voice-filter">
+                  <option value="">All languages</option>
+                  {% for key, label in options.languages.items() %}
+                  <option value="{{ key }}">{{ label }} ({{ key|upper }})</option>
+                  {% endfor %}
+                </select>
+              </div>
             </header>
             <div class="voice-available__list" data-role="available-voices"></div>
           </section>
@@ -92,8 +103,9 @@
 {% endblock %}
 
 {% block scripts %}
+  <script id="voice-mixer-options" type="application/json">{{ options | tojson | safe }}</script>
   <script>
-    window.ABOGEN_VOICE_MIXER_DATA = {{ options | tojson | safe }};
+    window.ABOGEN_VOICE_MIXER_DATA = JSON.parse(document.getElementById('voice-mixer-options').textContent);
   </script>
   <script type="module" src="{{ url_for('static', filename='voices.js') }}"></script>
 {% endblock %}
diff --git a/pyproject.toml b/pyproject.toml
index dad6101..a16632d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,6 +23,7 @@ dependencies = [
     "pygame>=2.6.1",
     "charset_normalizer>=3.4.1",
     "chardet>=5.2.0",
+    "python-dotenv>=1.0.1",
     "static_ffmpeg>=2.13",
     "Markdown>=3.9",
     "Flask>=3.0.3",