import { type ReactNode } from "react";
export interface SizeBuckets {
    small: boolean;
    medium: boolean;
    large: boolean;
}
export declare function deriveSizeBuckets(width: number): SizeBuckets;
/** Lands in the window's bucket for the first frame. */
export declare function screenSeedWidth(screen: SizeBuckets): number;
/** Null: no enclosing boundary, so the window is the container. */
export declare const ContainerSizeContext: import("react").Context<SizeBuckets | null>;
/**
 * Memoized on the buckets, not the width, so a resize within a bucket re-renders no consumer.
 * Renders nothing, so it is unit-testable; `size_boundary` measures.
 */
export declare function ContainerSizeProvider(props: {
    width: number;
    children: ReactNode;
}): import("react").JSX.Element;
export declare function useEnclosingContainerSize(): SizeBuckets | null;
/**
 * Put `measure` on the element as its `ref`. `null` without layout; with it, read as the element
 * attaches — before the first paint, so a surface forking on width never paints the wrong fork first —
 * then on every resize. The ref callback returns the disconnect as React 19's cleanup.
 */
export declare function useMeasuredWidth(): {
    measure: (node: HTMLElement | null) => (() => void) | undefined;
    width: number | null;
};
export interface MeasuredSize {
    width: number;
    height: number;
}
/**
 * Separate from `useMeasuredWidth` because a width reader must not wake on height changes (a mobile
 * keyboard) and a box reader must.
 */
export declare function useMeasuredSize(): {
    measure: (node: HTMLElement | null) => (() => void) | undefined;
    size: MeasuredSize | null;
};