/**
 * Save CSS content into a .css file with strict validation.
 *
 * @param {string} directory - The folder path where the file will be saved.
 * @param {string} filename - The name of the file (should end with .css).
 * @param {string} cssContent - The CSS content to be saved.
 * @returns {Promise<void>}
 * @throws {Error} If validation fails or write fails.
 */
export function saveCssFile(directory: string, filename: string, cssContent: string): Promise<void>;
export function getDefaultWindowFrameRoot(): string;
export function getDefaultWindowFrameStyle({ getElementName, fullscreenClass, blurClass, maximizedClass, }?: {
    getElementName?: ((className?: string, extra?: string, extra2?: string) => string) | undefined;
    fullscreenClass?: string | undefined;
    blurClass?: string | undefined;
    maximizedClass?: string | undefined;
}): string;
//# sourceMappingURL=CssFile.d.mts.map