import React, { type ReactNode } from 'react';
/**
 * Stable, synchronous boundary for SSR content. The drag/cascade implementation
 * is a sibling, not a replacement wrapper, so loading it cannot remount the app.
 * CSS handles initial and responsive geometry; only splitter interaction requests
 * the asynchronous chunk. The eager observer reads modes without changing widths.
 */
export declare function LayoutAreaSizingProvider({ children, layoutRef, }: {
    children: ReactNode;
    layoutRef?: React.RefObject<HTMLDivElement | null>;
}): JSX.Element;