import type { Instance } from 'flatpickr/dist/types/instance';
/**
 * Applies variant props (theme attributes) to a DOM element
 */
export declare function applyVariantProps(element: HTMLElement, variantProps: Record<string, string>): void;
/**
 * Sets up a MutationObserver to sync the 'active' attribute based on the 'selected' class.
 * Returns a cleanup function to disconnect the observer.
 */
export declare function setupActiveSyncObserver(dayElem: HTMLElement): () => void;
/**
 * Applies external CSS classes to the calendar container
 */
export declare function applyExternalClasses(container: HTMLElement, className?: string): void;
/**
 * Sets up dialog-specific behavior: ensures single-click opens the calendar
 * Returns a cleanup function to remove event listeners.
 */
export declare function setupDialogBehavior(calendarInstance: Instance): () => void;