/**
 * A custom React hook that detects whether the current device is a mobile device
 * based on the screen width.
 *
 * This hook uses a media query to check if the viewport width is less than the defined
 * mobile breakpoint (768px). It updates the state when the window size changes.
 *
 * @returns {boolean} Returns true if the viewport width is less than the mobile breakpoint,
 *                   false otherwise.
 *
 * @example
 * ```tsx
 * function MyComponent() {
 *   const isMobile = useIsMobile();
 *
 *   return (
 *     <div>
 *       {isMobile ? 'Mobile View' : 'Desktop View'}
 *     </div>
 *   );
 * }
 * ```
 */
export declare function useIsMobile(): boolean;