text: var navButton = document.querySelector('#navButton');
  var navMenu = document.querySelector('#navMenu');
  
  navButton.addEventListener('click', function () {
      if (navMenu.classList.contains('is-active')) {
          this.setAttribute('aria-expanded', 'false');
          navMenu.classList.remove('is-active');
          navMenu.setAttribute('aria-hidden', 'true');
      } else {
          navMenu.classList.add('is-active');
          this.setAttribute('aria-expanded', 'true');
          navMenu.setAttribute('aria-hidden', 'false');
      }
  });