/**
 * The one native iframe stays in the page-level layer for its entire lifetime.
 * Only its visible region changes when a menu opens; the conversation seat and
 * the iframe viewport never move or resize in response to hover.
 */
export declare function watchHarnessSurfaceViewport(surface: HTMLElement, frame: HTMLIFrameElement, seat: HTMLElement): () => void;
//# sourceMappingURL=harness-surface-viewport.d.ts.map