import type { Page } from '@playwright/test';
export declare const FREEZE_ANIMATIONS = "\n  *, *::before, *::after {\n    animation-duration: 0.001ms !important;\n    animation-delay: 0ms !important;\n    animation-iteration-count: 1 !important;\n    transition-duration: 0.001ms !important;\n    transition-delay: 0ms !important;\n  }\n";
/**
 * Navigate to the dev server, wait for a custom element tag to register,
 * freeze all animations, and clear the body for isolated component mounting.
 */
export declare function isolatedSetup(page: Page, url: string, waitForTag: string): Promise<void>;
/**
 * Replace body content with arbitrary HTML.
 * Custom elements are already registered from the dev server boot,
 * so they upgrade synchronously when inserted into the DOM.
 */
export declare function mount(page: Page, html: string): Promise<void>;