A sticky box is held so its *margin* box respects `top`, so the -24px
margin-top used to cancel .content's padding pushed the header's border box
24px down from the scrollport edge — rows scrolled through the strip above
it. Move the top padding off .content and onto .content-header instead: same
spacing at rest, opaque box flush with the scrollport when stuck.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
r-zakarya
bef739b7ca