Build an accordion

• Renders a list of items, each with a header button and a collapsible panel
• A multiple prop chooses between single-open (opening one closes the others) and multi-open behaviour
• Headers are buttons with aria-expanded and aria-controls; panels have role="region" and aria-labelledby
• Enter and Space toggle the focused header; Arrow Up and Down move focus between headers, Home and End jump to the first and last
• Open and close animate the panel height smoothly without a fixed pixel height
• Supports a defaultOpen set of item ids; collapsed panels are not reachable by Tab
• Works with any number of items, including zero

Only after every requirement works.

• Controlled mode with openIds and onChange
• Respects prefers-reduced-motion
• Nested accordions inside a panel