import { LitElement, TemplateResult } from "lit-element";
import { AriaRole } from "../util/aria";
/**
 * Backdrop properties.
 */
export interface IBackdropProperties {
}
/**
 * Dark layer to use behind overlayed elements.
 * @cssprop --backdrop-bg - Background.
 */
export declare class Backdrop extends LitElement implements IBackdropProperties {
    static styles: import("lit-element").CSSResult[];
    /**
     * Role of the backdrop.
     * @attr
     */
    role: AriaRole;
    /**
     * Returns the template of the element.
     */
    protected render(): TemplateResult;
}
declare global {
    interface HTMLElementTagNameMap {
        "wl-backdrop": Backdrop;
    }
}