export interface ThumbnailInput {
    html: string;
    styles: Record<string, string>;
    rect?: {
        x: number;
        y: number;
        width: number;
        height: number;
    };
}
export interface ThumbnailResult {
    png: Uint8Array;
    width: number;
    height: number;
}
export declare function thumbnailDocument(input: ThumbnailInput): string;
export declare function renderReferenceThumbnail(input: ThumbnailInput): Promise<ThumbnailResult | null>;