Whether the content is revealed. The children stay mounted either way, so state inside them survives a collapse.
Animates grid-template-rows from 0fr to 1fr rather than a height or a
max-height. That means the open height is the content's natural height — no
measuring, and no max-height guess that clips tall content or adds a pause
before short content finishes opening. The inner min-h-0 overflow-hidden
wrapper is what makes the grid row actually shrink.
Collapsed content is hidden but still in the accessibility tree and still
focusable; pair the trigger with aria-expanded so the state is announced.
A section that eases open and shut around whatever it wraps.