Version 2.4.0 is an architectural and maintenance update focused on security, code maintainability, and project structure. The user-facing features and interface remain unchanged, but the underlying codebase has been fully reorganized to meet current extension development standards.

• Removed innerHTML: Addressed Mozilla Add-on Store security feedback by replacing all innerHTML assignments with a secure DOMParser implementation to strictly prevent Cross-Site Scripting (XSS) risks.

• Directory Restructuring: Migrated from a flat file layout to a modular src/ based directory structure, isolating concerns into background, content, and popup components.
• Content Script Modularization: Split the monolithic content script into distinct modules:
• content.js: Handles core audio interception, Web Audio API routing, and DRM detection.
• widget.js: Manages the in-page floating UI logic, dynamically extending the audio controller.
• CSS Extraction: Removed inline <style> tags from HTML files and DOM injections. All styles are now maintained in dedicated .css files, with the widget styles loaded at runtime.

• Documentation and Typing: Applied strict mode ('use strict') across all JavaScript files. Documented all classes, methods, and parameters using JSDoc annotations.
• Code Cleanup: Extracted magic numbers and hardcoded strings into named constants. Replaced lengthy if/else chains with switch statements for cleaner message routing.
• Build Process: Introduced a shell script (build.sh) to automate the creation of clean, store-ready deployment archives. Added a .gitignore to prevent tracking of build artifacts and environment files.

• Enhanced Security Standards: Removed all innerHTML assignments across the extension to prevent Cross-Site Scripting (XSS) vulnerabilities.
• Store Policy Compliance: Fully updated DOM manipulations using DOMParser to comply with strict Mozilla Add-ons and Chrome Web Store security guidelines.

• Menu UI Optimization: Refined the popup menu layout for better usability and a more polished look.
• Volume Slider Fixes: Resolved issues with the volume slider behavior to provide a smoother and more precise volume control experience.

• DRM Compatibility (MUBI & others): Fixed errors related to DRM-protected content (like MUBI). The extension now correctly identifies DRM-protected media and safely limits volume boosting to prevent audio distortion or playback crashes.

Notes to Reviewer (for Add-on Store Submission):
* All previous innerHTML warnings flagged by the validation tool have been addressed by implementing a safe setSafeHTML helper using DOMParser.
* No external libraries or minified code are included.

TabMixer v2.3.2 Release Notes

Bug Fixes
* Fixed a critical issue where lowering the volume slider below 100% triggered an asynchronous loop, causing the audio to unexpectedly drop to zero (mute).
* Resolved a double-dipping volume bug on non-DRM websites where volume changes were incorrectly applied to both the native media element and the Web Audio API gain node simultaneously.

UI & Theme Improvements
* Updated the primary extension theme to a refined, dark olive green.
* Redesigned the volume sliders in both the extension popup and the floating page widget to dynamically fill with the new theme color as the volume increases.
* The widget toggle switch and state buttons (Mute/Reset) now seamlessly match the updated color scheme.

TabMixer 2.3.1 Update

• Improved volume control compatibility for web audio players including Spotify.
• Updated button accent color theme to sage green for muted and active states.
• Automatically prefix missing site names in tab titles for better clarity.
• Refined UI layout and volume slider styling for light and dark themes.

TabMixer 2.3.0 Update

🎨 Minimalist Slider Design: Replaced the colorful rainbow track with a sleek, modern, neutral slider design that seamlessly integrates with light & dark themes.
🎵 Smart Tab Titles: Automatically prefixes tab titles with site names (e.g., "YouTube | Song Title") when missing for quick tab identification.
📐 Overflow & Layout Fixes: Improved title truncation and scrollbar prevention for a clean, compact interface.

TabMixer 2.2.0 Update

🎵 Smart Tab Titles: Added automatic site name prefixes (e.g. "YouTube | Song Name") to tabs when missing, making audio sources easier to identify.
✨ Clean UI & No Scrollbars: Improved title truncation and popup overflow handling for a smooth, scrollbar-free interface.

TabMixer 2.1.0 Update

↺ Per-Tab Reset Button: Added an individual reset button to each tab item so you can reset specific tab volume to 100% with a single click.
🎨 Light & Dark Mode: Full automatic theme support matching system and browser dark/light mode preferences for both popup UI and in-page widget.
📐 UI Refinements: Moved the "Reset All" button to the header corner for a cleaner and more compact interface.

TabMixer 2.0.0 — Major Update

🎛 In-Page Volume Widget A floating volume control now appears directly on pages playing audio. Click the speaker icon in the bottom-right corner to quickly adjust volume without opening the popup. Can be toggled on/off from the popup settings.

🔒 DRM Compatibility TabMixer now works on DRM-protected sites like Netflix, Spotify, MUBI, and Disney+. Volume control (10–100%) is available on these sites using safe direct control that never interferes with content playback. No more "DRM Protected" warnings.

🧠 Automatic DRM Detection Replaced the hardcoded site list with real-time EME (Encrypted Media Extensions) detection. TabMixer automatically detects DRM content and adjusts its behavior — no manual configuration needed.

🔊 Volume Boost Non-DRM sites continue to support volume boost up to 150% via Web Audio API.

🖼 Store-Ready Icons Added 48px and 128px icon sizes for better display across Firefox UI.

Initial release of TabMixer

Features:
- Individual volume control per tab (10-150%)
- Per-tab mute/unmute functionality
- Smart reset button for all tabs
- DRM content detection with clear warnings
- Privacy-focused: no data collection, all settings stored locally
- Minimal and lightweight design

Technical:
- Manifest V2
- Zero external dependencies
- Local storage only