/**
 * Returns the combined height (px) of the sticky page header and announcement
 * bar (if present), updated live via ResizeObserver / MutationObserver.
 * Useful for offsetting fixed/absolute-positioned panels so they don't
 * overlap the header.
 */
export declare function useHeaderHeight(defaultHeight?: number, options?: {
    /**
     * When false, no observers are attached and the default height is
     * returned — for consumers that stay mounted on every page but only need
     * the measurement while an overlay is open (avoids an always-on
     * document-wide MutationObserver + forced reflow).
     * @default true
     */
    enabled?: boolean;
}): number;
//# sourceMappingURL=use-header-height.d.ts.map