jheapsandClaude Opus 5
02c2a034cb
WCAG 2.2 SC 2.4.11 asks that a focused control not be completely hidden
by something the page has put on top of it. The bar is fixed over the
bottom and is not in the flow, so the browser does not know it is there:
Tab to a control near the bottom and it is scrolled flush against the
edge of the window, under the bar, and the browser considers it done.
Tabbing the whole page measured 16 stops resting completely covered on a
390x844 phone and 27 more partly, plus four under a toast on the desktop.
It is now 0 and 0 on desktop, phone and a phone on its side — clean
against 2.4.12 (AAA) as well, which allows no overlap at all.
Three things were wrong and they needed different answers.
scroll-padding-bottom on the scroll container, sized from the bar's own
published height and the toast's, handles the case where the browser has
to scroll to reach the control. That is half of it, and the half that
looks like all of it: a control the browser already considers visible is
one it will not scroll to, and a fixed overlay on top does not enter into
that decision. Measured — tabbing to Common rulings with a toast up left
it 100% covered and scrollIntoView({block:"nearest"}) moved nothing. So a
focusin handler measures the overlap and scrolls by it, and when the page
has no room left (26px against 94px wanted) the toast gives way instead.
Sizing the page padding for the toast would have fixed that by making the
page grow and shrink 64px whenever anything was announced.
The page's room to scroll past the bar was 9rem on the sidebar alone,
which left the table's column — most of a desktop — with none. It is now
on the whole app and taken from the bar's real height, so it is also 0 in
the layout where the bar is a rail down the side.
And the seat editor's bottom sheet was put away with a transform, which
moves a thing without putting it away: its Done button sat at y=850 on an
844px screen, focusable, announced, and impossible to scroll to, because
a fixed element does not move when the page does. visibility:hidden puts
it away, transitioned so the slide-out still runs.
uiAudit.js gained focusHasRoom() and focusablesReachable() for the two
static halves. Audit unchanged at 2 failing configurations and 3
offenders, both pre-existing. 805 unit tests pass.
Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015bnp7xKUPFFSpwkYNFaPgb