CSS Anchor Positioning + Popover API: Tooltips With No JS Library

Three tooltips pinned to their trigger button using nothing but the native Popover API (popover/popovertarget attributes, no click-handler JS) and the new CSS Anchor Positioning spec (anchor-name on the button, position-anchor + position-area on the tooltip). This is the pairing that replaces Popper.js/Floating UI + a popover library entirely - zero JavaScript. Includes an @supports not (anchor-name: --a) fallback note for browsers that don't support anchor positioning yet (the popovers still open, just without the pinned position).