The palette's dialog overlay/content are position: fixed, but were DOM-descendants of the sticky nav <header>, which has backdrop-blur (backdrop-filter). Per the CSS spec, an ancestor with backdrop-filter becomes the containing block for fixed descendants, so the dialog was positioned relative to the 64px header instead of the viewport — top: 50% resolved to ~32px and translate(-50%, -50%) shoved most of the dialog above the viewport, leaving only the bottom half visible. Fix: keep the trigger button inside the nav header (where it belongs visually) but render the dialog LiveComponent as a sibling of <header>, outside the backdrop-filter containing block. The existing #command-palette-content CSS override then centers correctly relative to the viewport. Adds a regression test asserting the dialog markup appears after </header>.