Four things the band's content-sizing exposed, all of them stale assumptions
from when it was a full-window box.
A leftover `:focus-within` rule still painted the band's own background, so
focusing an empty session filled the whole window with a solid slab even though
the sheet had correctly collapsed to nothing.
The exit chip anchored to the band rather than the sheet, so on a short
transcript it floated in empty space at the window's corner. It now rides the
sheet, and drops clear of the bar when the layout is flipped.
Bottom clearance read `--composer-measured-height`, a surface var that never
reaches here, so it silently fell back to the root estimate and reserved ~20px
more than the bar occupies. The bar's real height is measured alongside the
band's.
Top-edge mode was never re-checked after the sheet started sizing itself: the
sheet stayed pinned to the bottom while the transcript hung from the top. Both
the anchor and the measurement now flip with the layout.
Brooklyn Nicholson
6ada733f9d