/**
 * Finds the closest ancestor element of the given base element that matches the provided CSS selector.
 *
 * @param {string} selector - The CSS selector to search for.
 * @param {Element} base - The base element to start the search from.
 * @returns {Element | null} - The closest ancestor element matching the selector, or null if none is found.
 */
export declare function closestElement(selector: string, base: Element): Element | null;