/**
 * Viewport signals for the debug overlay.
 *
 * Two ORTHOGONAL signals, deliberately kept apart:
 *
 * - `compact` drives **layout** — which shape a surface takes (logo-anchored drawer
 *   vs corner dropdown, full-screen modal vs floating one). Narrow OR short viewport.
 * - `coarse` drives **hit targets** — how big a tappable thing must be. True on
 *   any touch device, including large tablets.
 *
 * They cross: a tablet is coarse-but-not-compact (desktop layout, big targets);
 * a narrow desktop window is compact-but-not-coarse (mobile layout, normal
 * targets). Collapsing them into one "isMobile" boolean gets both cases wrong.
 *
 * This module imports nothing from the overlay — keep it a leaf so `core.ts`,
 * `panel.ts` and `predict.ts` can all depend on it without cycles.
 */
export type LayoutState = {
    compact: boolean;
    coarse: boolean;
};
/** Re-run every subscriber. Call directly after changing a preference that affects layout. */
export declare function reflow(): void;
/** Subscribe to viewport/layout changes. Returns an unsubscribe function. */
export declare function onReflow(fn: (state: LayoutState) => void): () => void;
/** True when the viewport is narrow or short — the overlay switches shape. */
export declare function isCompact(): boolean;
/** True on touch/stylus input — hit targets grow to 44px. Independent of {@link isCompact}. */
export declare function isCoarsePointer(): boolean;
/** Install the one listener set that drives every relayout. Idempotent. */
export declare function initLayout(): void;