YouTube True OLED Black by Mars

I prefer to watch videos in theater mode rather than fullscreen so I built this Add-on for my personal use.

Repaints the page background, masthead, sidebar, and theater letterboxing to true black.
Activates only when YouTube's own dark theme is enabled.

Optional "Hide unused chrome" toggle removes Voice search, the Create button, Super Thanks, the watch-page three-dot menu, and the notifications bell + account avatar while watching a video.

The video itself, player controls, hover states, and selected chips are deliberately left alone so the UI stays usable.