/**
 * Returns `true` if the browser supports the Popover API (top-layer).
 *
 * When supported, elements with `popover="manual"` can be promoted to the
 * browser's top layer via `element.showPopover()`, which is more reliable
 * than `z-index` for ensuring an element renders above everything else.
 *
 * @see https://developer.mozilla.org/en-US/docs/Web/API/Popover_API
 */
export declare const supportsPopover: () => boolean;