restore full CSS, apply only pack-menu changes
the previous commit rewrote the entire style.css and dropped ~220
lines of rules (search form, typeahead, progress bar, results,
modals, etc.), nuking the site layout. this restores the known-good
CSS from 39daa31 and applies only the targeted pack-menu changes:
kill the pill border/padding, make the trigger inline text, add
margin-left: auto on the share button.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>