/**
 * The shared layout width. Dragging any [LAYOUT] stage handle sets it for
 * every layout page and it survives reloads (localStorage, like the theme).
 * Null means "no override": layouts sit at full width. Clicking a layout's
 * width readout clears it. Component previews and examples keep their own
 * per-page widths — sketch pages are where a remembered viewport pays off.
 */
/** Load the persisted width (Explorer calls this on mount). */
export declare function initLayoutWidth(): void;
/** The override in px, or null when stages sit at their defaults. Reactive. */
export declare function layoutWidth(): number | null;
export declare function setLayoutWidth(v: number): void;
export declare function clearLayoutWidth(): void;