import { SurfaceRung } from '../../tokens/colors';
/**
 * What a `Surface` publishes to its descendants.
 *
 * This travels through React context, which — unlike the CSS custom properties
 * the same component emits — crosses portals. That difference is the whole
 * reason portalled overlays need to re-declare a rung: they can still *read*
 * where they came from, but the browser will not inherit the variables to them.
 *
 * Kept in its own module so `Surface.tsx` exports only a component and stays
 * eligible for fast refresh.
 */
export interface SurfaceContextValue {
    /** How many surfaces deep, counting this one. The app shell is 0. */
    depth: number;
    /** The rung this surface resolved to. */
    rung: SurfaceRung;
}
export declare const SurfaceContext: import('react').Context<SurfaceContextValue | null>;
/** The root defaults, used when a component is rendered outside any `Surface`. */
export declare const ROOT_SURFACE: SurfaceContextValue;
/**
 * The rung of the nearest enclosing `Surface`, and how deep it is.
 *
 * Returns the root defaults outside any surface, so a component can call this
 * unconditionally.
 */
export declare function useSurface(): SurfaceContextValue;
/**
 * The rung a portalled child of the current surface should render on.
 *
 * For overlay components that MUI reparents to `document.body`. See
 * `portalRung` for why it is `max(raised, host + 1)` rather than `host + 1`.
 */
export declare function usePortalRung(): SurfaceRung;