/** True when the OS or the page asks for less motion. Safe anywhere, SSR included. */
export declare function reducedMotion(): boolean;
/** Runs `fn` with the effective preference whenever it changes. Returns the unsubscribe. */
export declare function onMotionChange(fn: (reduced: boolean) => void): () => void;
/**
 * The page's own switch. `'reduce'` asks for less motion whatever the OS
 * says; `'auto'` follows the OS again. Persisting the choice is the page's
 * job (a cookie, storage, a server preference): set it before the first
 * frame and nothing animates first and calms down later.
 */
export declare function setMotion(mode: 'reduce' | 'auto'): void;