Added:
- Arabic-only mode to apply styling only when Arabic script is detected.
- Per-surface toggles for Titles, Descriptions, Comments, and Captions.
- Advanced custom font-family input (with fallback to selected preset font).
- Import/Export settings as JSON.
- “Apply to open tabs now” action.
- Status feedback showing how many YouTube tabs were updated.
- Preview mode switch (styled-only vs before/after preview).
- Glassmorphic popup UI with accessibility-safe contrast and a non-blur fallback.

Improved:
- SPA reliability on YouTube by handling yt-navigate-finish in addition to mutation/URL checks.
- Style re-application performance by avoiding unnecessary style reinjection when CSS has not changed.
- Dynamic content handling for frequently updated YouTube sections.
- Arabic and English help text clarity in popup and docs.
- Compatibility / Behavior
- Backward-compatible settings migration for existing users.
- Existing users keep prior preferences; new keys are merged with sensible defaults.
- No change to privacy model (data_collection_permissions: none remains intact).

Notes:
- Styling coverage still depends on what YouTube exposes outside closed Shadow DOM trees.