export declare function prefersReducedMotion(): boolean;
/** Test seam: forget the cached MediaQueryList so a stubbed matchMedia applies. */
export declare function resetReducedMotionCache(): void;
/** Active VT type for markdown crystallize — scoped CSS, not a full-page blink. */
export declare const MARKDOWN_CRYSTALLIZE_VT_TYPE = "og-md-crystallize";
/**
 * Run a DOM update inside the browser View Transition API when available.
 * Snapshots the before/after paint and cross-fades (or custom CSS morphs)
 * between them — the platform "morph" primitive React's experimental
 * `<ViewTransition>` wraps. Falls back to a synchronous update.
 */
export declare function runViewTransition(update: () => void, options?: {
    types?: string[];
}): void;