E28 S3d1 moved the modal's card from `.glass-card` (no blur) to the `.glass` panel role, whose
`backdrop-filter` makes the card the containing block of the fixed "full window" stage: F showed a
894×161 strip inside the card with a scrolling, wrapped control bar. While the stage is maximised the
card now drops its blur (`html .glass:has(> .player-stage--max)`, outranking the dark theme's rule);
measured live: the stage 1268×861 = the viewport, the blur back on exit.