/**
 *
 * @param targetSelector
 * @param apply: Array with objects containing the following properties:
 *  - selector Which elements to find and apply the style to
 *  - style The css styles to apply
 *  - shadowDomSelector (optional) If the elements are in a shadow dom, you can specify the selector to find the shadow dom (e.g. 'my-element'
 * @returns
 */
export declare function watchAndApplyStyle(targetSelector: string, apply: Array<{
    selector: string;
    style: Record<string, string>;
    shadowDomSelector?: string;
}>): MutationObserver | undefined;
