The nav's .glass backdrop-filter makes it a containing block for fixed descendants and a
stacking context, so the account popover's fixed inset-0 backdrop only covered the nav (not
the viewport) and the popover sat below the main content — controls behind it stayed
clickable. Portal the popover + its dismiss backdrop to <body> with fixed coords computed
from the trigger rect, so it's truly top-most (z-50) and blocks clicks underneath.
peter
5bb85b039a