/**
 * A <needle-button> can be used to simply add VR, AR or Quicklook buttons to your website without having to write any code.
 * @example
 * ```html
 * <needle-button ar></needle-button>
 * <needle-button vr></needle-button>
 * <needle-button quicklook></needle-button>
 * ```
 *
 * @example custom label
 * ```html
 * <needle-button ar>Start AR</needle-button>
 * <needle-button vr>Start VR</needle-button>
 * <needle-button quicklook>View in AR</needle-button>
 * ```
 *
 * @example custom styling
 * ```html
 * <!-- You can either style the element directly or use a CSS stylesheet -->
 * <style>
 * needle-button {
 *    background-color: red;
 *   color: white;
 * }
 * </style>
 * <needle-button ar>Start AR</needle-button>
 * ```
 */
export declare class NeedleButtonElement extends HTMLElement {
    #private;
    static observedAttributes: string[];
    constructor();
    attributeChangedCallback(_name: string, _oldValue: string, _newValue: string): void;
}