The rail track bleeds past the viewport (padding plus negative margin) so
card focus rings are not clipped, but the edge fades were anchored to the
viewport. That left a strip of the partly visible card beyond each fade.
Share the bleed through a --rail-bleed custom property used by the track
padding/margin, its scroll padding and the fade offsets, so they cannot
drift apart. Raise the bleed from 4px to 8px: the card focus ring needs 5px
(2px outline + 3px offset) and 7px with the hover lift, so the first/last
card's ring was losing a pixel.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
