Evidence (sharp video behind overlays) shows backdrop-filter is a no-op here, most
likely because browser hardware acceleration is off — so the glass relied on a blur
that never rendered. Lean on opacity instead (94% surface) so overlay menus/panels
read as frosted glass regardless of GPU; keep the blur as a bonus when available.
Revert the settings backdrop to a plain dim scrim (no whole-page blur) and make the
header a solid bar (no backdrop-filter ancestor).
peter
f429889250