/**
 * Walks up from `from` to find the nearest ancestor that actually scrolls.
 * Falls back to the document root so embedding the widget in a plain,
 * non-scrolling page still locks the page scroll as expected.
 */
export declare function getScrollLockTarget(from: Element | null): HTMLElement;
/**
 * Finds a scroll lock target without escaping `boundary`. This is used by
 * component-contained overlays: an ancestor owned by the host page must not
 * be locked merely because the widget itself has no scroll container.
 */
export declare function getContainedScrollLockTarget(from: Element | null, boundary: Element | null): HTMLElement | null;
/**
 * Locks scroll on `target` and pads it to compensate for the scrollbar
 * that disappears, so surrounding content doesn't shift. Returns a
 * function that restores the original styles.
 */
export declare function lockScroll(target: HTMLElement): () => void;