e03ff49764
- Restore explicit overflow-y:auto on #main-app for mobile (removed in
63f5d64) — implicit coercion from overflow-x:auto is not reliable in
all Safari/WebKit versions.
- Override position:sticky on .readme to position:relative on mobile.
The desktop sticky (left:0) is correct for horizontal scroll, but on
mobile vertical scroll it pinned the 100dvh-tall readme across the
entire viewport, hiding all stacked notes behind it.