/**
 * Central registry for open modal overlays (Dialog, Drawer, Sidebar).
 *
 * The browser already handles top-layer stacking and ESC-to-close for native
 * `<dialog>` elements. This stack adds three things on top of that:
 *
 * 1. **Programmatic close-all** — useful on logout, route changes, or auth
 *    expiry, where leaving stacked modals open creates UX confusion.
 * 2. **Inspection** — `depth` and `topId` for tests, debug overlays, or
 *    conditional UI logic (e.g. "hide the help-tooltip while a Drawer is
 *    open").
 * 3. **Stack-aware close-top** — `closeTop()` resolves the most recently
 *    registered overlay regardless of which component owns it.
 *
 * Each overlay registers itself on open with a `close` callback and
 * deregisters on close. Registration is keyed by an opaque ID — typically
 * generated via `crypto.randomUUID()` so multiple instances of the same
 * component type can coexist in the stack.
 *
 * @example
 * ```ts
 * // Inside a Drawer / Dialog / Sidebar component:
 * $effect(() => {
 *   if (!open) return;
 *   const id = crypto.randomUUID();
 *   return overlayStack.register(id, () => { open = false; });
 * });
 * ```
 *
 * @example
 * ```ts
 * // App-level: close everything on logout
 * import { overlayStack } from '@urbicon-ui/blocks';
 *
 * function logout() {
 *   overlayStack.closeAll();
 *   goto('/login');
 * }
 * ```
 */
declare class OverlayStack {
    /** Internal entry list. Reactive so consumers can derive UI from `depth`. */
    private entries;
    /**
     * Register an open overlay. Returns an unregister function — store it as
     * the cleanup of an `$effect` so the entry is removed when the overlay
     * closes or the component unmounts.
     *
     * Reads of `entries` are wrapped in `untrack` so callers calling this from
     * within an `$effect` don't accidentally subscribe to the entries list —
     * otherwise the write below would re-trigger the calling effect on every
     * registration, producing `effect_update_depth_exceeded`.
     */
    register(id: string, close: () => void): () => void;
    /** Remove an overlay from the stack without invoking its close callback. */
    unregister(id: string): void;
    /**
     * Invoke the close callback of every registered overlay, top-down. Each
     * callback is responsible for unregistering itself (typically by setting
     * `open = false` and letting the `$effect`-cleanup run).
     */
    closeAll(): void;
    /** Close only the topmost overlay. No-op if the stack is empty. */
    closeTop(): void;
    /** Number of currently open overlays. */
    get depth(): number;
    /** ID of the topmost overlay, or `null` if the stack is empty. */
    get topId(): string | null;
    /** True if the given ID is the topmost overlay. */
    isTop(id: string): boolean;
}
/** Singleton overlay stack. Import and use directly. */
export declare const overlayStack: OverlayStack;
export {};