Checkbox

This draft family contains a Root and an Indicator. Base Checkbox owns controlled and uncontrolled checked, the author-controlled indeterminate display state, effective disabled behavior, pointer and Space activation, focus, and the accessible checkbox role including aria-checked="mixed".

The Brutalist layer is presentation-only. Checked and mixed use the pinned Neo main/foreground pair, with a 16px, 2px rounded-stroke aria-hidden check or distinguishable mixed dash. The existing 20px Root and 2px internal frame are temporarily retained: the source 16px external-outline recipe needs a governed hit envelope and supported outline-color translation before it can replace the current target without reducing reach. Outline paint alone does not enlarge the hit area. Indicator derives state from the nearest Root and owns no control semantics; mixed still wins. Current browser glyph clipping, hit testing and long-label verification remain pending.

Import Root and Indicator from the already-public @proto.ui/prototypes-brutalist package or its @proto.ui/prototypes-brutalist/checkbox anatomy subpath. This family intentionally has no proto-ui add brutalist-checkbox registry entry and creates no separate publication or release promise.

1. Activate the Unchecked, Checked, and Mixed examples with pointer and Space.
2. Confirm the Disabled example cannot change.
3. Tab to the named Focus-visible target and confirm the hard ring appears on Root without moving focus to Indicator.
4. Confirm the Checked and indeterminate example paints the mixed dash rather than the tick.
5. Repeat in Web Components, React, Vue, and Vue 2, in both Light and Dark.

The related catalog entities are draft; this page records the current direction rather than a stable Checkbox guarantee.