import { ReactNode, ReactPortal } from 'react';
/**
 * Returns the portal host element `#id`, creating it when missing.
 *
 * @remarks
 * If the element is missing, a `div` with the given `id` is appended to `document.body`.
 * The portal mounts **into** that host — `document.body` itself is never used as the
 * direct portal container.
 *
 * @param rootId - `id` of the root node (e.g. `'dialog-root'`).
 *
 * @returns The host element, or `null` when `document` is unavailable (e.g. SSR).
 *
 * @category Utils
 */
export declare function ensurePortalRoot(rootId: string): HTMLElement | null;
/**
 * Renders children into a dedicated portal root, creating that node when absent.
 *
 * @remarks
 * Uses {@link ensurePortalRoot}; returns `null` when the document is not available.
 *
 * @param rootId - `id` of the portal host (e.g. `'dialog-root'`).
 * @param children - Tree to render into the host.
 *
 * @returns A {@link https://react.dev/reference/react-dom/createPortal | React portal}, or `null`.
 *
 * @category Utils
 */
export declare function renderPortal(rootId: string, children: ReactNode): ReactPortal | null;