For tracking issue

- https://bugzilla.mozilla.org/show_bug.cgi?id=1711609
- https://bugzilla.mozilla.org/show_bug.cgi?id=1713420
- https://www.reddit.com/r/firefox/comments/nqoq3t/some_of_tickets_on_bugzilla_for_new_ui/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1702480

Light/Dark UI at v110 nightly
- https://bugzilla.mozilla.org/show_bug.cgi?id=1704347
- https://bugzilla.mozilla.org/show_bug.cgi?id=1806945
- https://www.reddit.com/r/firefox/comments/zsnyw9/new_default_dark_theme_looks_really_bad_in_latest/
- https://www.reddit.com/r/firefox/comments/ztecpx/new_firefox_nightly_dark_theme_does_anyone_like_it/

The issue is a tracking list of Bugzilla and Reddit links, with no repository file, test, or entry point named. Review the linked discussions and the Firefox UI customization project context first; the scope and definition of done cannot be determined from this issue alone.

Written by the indexing model from the issue text.