Theme preference stored in localStorage (auto follows the OS setting).
The chosen data-theme attribute is applied synchronously in <head> to
avoid any flash of unstyled content. CSS custom properties handle all
surface, text, border and input colours across every page. The
Appearance section on the profile page lets each user switch modes.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Andreas Wrede
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