Accessibility contracts

Patterns

Primitive	Pattern
Select, Listbox	WAI-ARIA listbox; Select trigger aria-haspopup="listbox"; aria-multiselectable when multiple
Combobox	Editable combobox with aria-activedescendant; DOM focus stays on the input
Dialog	Modal dialog with focus trap, background inert, focus restoration
Menu, Popover, Tooltip	Menu button, non-modal dialog, tooltip description
Tabs, Accordion, RadioGroup, ToggleGroup	Roving focus, orientation and RTL aware
Checkbox, Switch, Toggle, Slider	Native-button / ARIA slider semantics

Selection groups

Option groups are role="group" named by their label (aria-labelledby); group labels and separators are not options, so keyboard navigation and typeahead skip them. ARIA does not allow separator inside a listbox, so qz*Separator is decorative (aria-hidden). Disabled options are skipped and carry aria-disabled.

Combobox rules

• aria-expanded mirrors the popup; aria-controls is present only while the listbox exists, so there is never a dangling reference.
• aria-activedescendant is cleared when the popup closes.
• During IME composition the query is neither filtered nor committed, and Enter belongs to the IME.

Focus

Closing a popup by Escape or selection returns focus to the trigger; Tab hands focus back before the browser moves it so tabbing continues from the trigger's position.

What is verified

Automated: axe-core scans of representative open/active states in Chromium, Firefox and WebKit, and unit/E2E tests for keyboard and ARIA state. Not verified: manual screen-reader output and formal WCAG conformance.