/**
 * Dark mode capture — screenshot pages in both light and dark color schemes.
 *
 * Uses Playwright's page.emulateMedia({ colorScheme: 'dark' }) to force dark mode,
 * then captures a screenshot. Compares with light mode to determine if dark mode
 * is supported (significant visual difference).
 *
 * Also detects prefers-color-scheme media query support in CSS.
 */
import type { Page } from 'playwright';
export interface DarkModeCapture {
    url: string;
    lightScreenshot?: Buffer;
    darkScreenshot?: Buffer;
    hasDarkMode: boolean;
    hasCssDarkMode: boolean;
    backgroundColorLight?: string;
    backgroundColorDark?: string;
    capturedAt: string;
}
export declare function captureDarkMode(page: Page, url: string, opts?: {
    takeScreenshots?: boolean;
}): Promise<DarkModeCapture>;