Release notes — v1.4.0
New: pick any element, not just detected videos
The control panel (toolbar icon) now has a Select element… button. Click it, hover the page — whatever is under the cursor gets a highlight outline with a tag#id.class label — and click to send that element to theater mode. Esc or right-click cancels the picker; the page never sees the picker's clicks.

The element you pick is authoritative:

Container with a video inside (any player UI) → the whole container goes theater, controls stay clickable.
Bare <video> → the video itself fills the screen.
Overlay/cover element over a video → falls through to that video's usual player container.
Same-origin <iframe> → the video inside the frame, elevated with its player UI.
Cross-origin <iframe> embed or closed-shadow-root player → the element is elevated as-is ("videoless" theater). While such an embed is theatered, its own fullscreen button toggles the theater too, and Esc inside or outside the frame exits — no more competing double theaters.
Fixed / polished
YouTube: the control bar now spans the full screen width and the video stays dead-center in theater mode (stale cached inline layout is re-measured on enter/exit).
Theater mode now works on elements without a video, with a clean abort if the target can't be painted.
No behavior changes to existing entry points: the Theater pill button, the Ctrl+Shift+F shortcut and fullscreen redirection work exactly as before.
No new permissions; nothing is collected or sent anywhere.

Fixed theater mode on YouTube (and players with a similar structure).

• The fullscreen button and the F key now open theater mode correctly on
YouTube — previously you'd get only a dimmed page with no video. YouTube
requests fullscreen on the page root, which the extension mistakenly
treated as the player; it now finds the actual player container.
• Theater mode now elevates the real player container, so YouTube's own
controls (seek bar, volume, settings, fullscreen) stay visible and
clickable inside the theater view.
• Videos wrapped in collapsed containers (a technique YouTube and some
custom players use) no longer shrink to zero height in theater mode.
• The theater view now reliably covers site headers and sidebars that
could previously paint on top of the video.