import { MegaMenuOptions } from './mega-menu.types';
/**
 * Headless mega-menu controller. A horizontal bar of top-level triggers, each
 * optionally opening a large multi-column panel. Opens on hover/focus/click,
 * closes on Escape / outside-click / focus-leave, and supports arrow-key
 * navigation between triggers. Implements the disclosure-menu ARIA pattern
 * (buttons with `aria-expanded`/`aria-controls`); it applies no visual styles.
 *
 * Markup:
 * ```html
 * <nav data-c42-mega-menu aria-label="Main">
 *   <ul>
 *     <li data-c42-mega-menu-item>
 *       <button data-c42-mega-menu-trigger data-value="products">Products</button>
 *       <div data-c42-mega-menu-panel>…multi-column content…</div>
 *     </li>
 *     <li data-c42-mega-menu-item>
 *       <a data-c42-mega-menu-trigger href="/pricing">Pricing</a>
 *     </li>
 *   </ul>
 * </nav>
 * ```
 */
export declare class MegaMenu {
    private readonly root;
    private readonly items;
    private readonly openOnHover;
    private readonly openDelay;
    private readonly closeDelay;
    private openItem;
    private timer;
    private cleanups;
    constructor(root: HTMLElement, options?: MegaMenuOptions);
    private collectItems;
    private get triggers();
    private init;
    private clearTimer;
    private scheduleOpen;
    private scheduleClose;
    private onTriggerKeydown;
    private openMenu;
    private closeItem;
    /** Open a panel by its item value. */
    open(value: string): void;
    /** Toggle a panel by its item value. */
    toggle(value: string): void;
    /** Close any open panel. */
    closeAll(): void;
    get openValue(): string | null;
    /** Subscribe to a DOM event on the root element. Returns an unsubscribe fn. */
    on<E extends Event = Event>(event: string, handler: (event: E) => void): () => void;
    destroy(): void;
}