Popover / Menu (v3.4.5)
Anchored menu / popover runtime. Lab module only — not promoted to baseline. See
docs/POPOVER-AUDIT.md for rationale, Beer CSS intake notes, and a11y risk register.
Anchored menu
Click "Open menu" to anchor a menu under the trigger. Verify focus moves to the first menuitem, ArrowDown/ArrowUp navigates, Escape closes and returns focus to the trigger, and clicking outside closes without firing the trigger again.
Split-button menu
Primary action on the left button; secondary actions in the menu opened by the chevron
button on the right. Verify the chevron aria-expanded toggles correctly
and the menu anchors under the chevron, not under the primary action.
Forbidden-ancestor bail-out
A trigger placed inside .prose should be ignored — the menu
must not open. This protects federation content surfaces (Charter §5, §6) and editor
[contenteditable] regions from theme-side interaction firing inside
user-authored content.
↓ The button below is inside .prose. Clicking it should do nothing. The
menu (rendered separately, outside .prose) cannot be opened from here.
이 문단은 .prose 안에 있습니다. 아래 버튼은 무시되어야 합니다.