React

Peer dependencies, not bundled

react and react-dom are peers and are left external in the build. Bundling React would give you two copies and break hooks, so the package resolves to whichever React your app already has — 19 or newer.

Controlled and uncontrolled

Two components keep their own state unless you drive them:

• Switch — pass on to control it; leave it out and it keeps its own, seeded from defaultOn. onChange(on, event) reports the value it is moving to.
• Accordion — pass state to control it; leave it out and it keeps its own, seeded from defaultState. onToggle(state, event) likewise.

When you control one, the component does not move on its own — the value you pass wins, and acting on the callback is your job.

Accessible names

Some components cannot name themselves, because the design draws no label layer:

• Switch needs aria-label or aria-labelledby from you.
• Field renders the label and you supply the control; controlId is what ties them together.
• An icon-only Button takes its name from label.

Each component’s Usage tab lists its accessibility facts with a link to the line that makes each one true.

Server rendering

Every component renders to static markup with react-dom/server; the test suite asserts it for both the ESM and the CJS build.