如何让导航栏在缩放时消失？

@media (max-width: 768px) {
  .navbar {
    display: none;
  }
}

window.addEventListener('resize', function() {
  var navbar = document.querySelector('.navbar');
  if (window.innerWidth <= 768) {
    navbar.style.display = 'none';
  } else {
    navbar.style.display = 'block';
  }
});

.navbar {
  transition: opacity 0.3s;
}

.navbar.hidden {
  opacity: 0;
  pointer-events: none;
}

window.addEventListener('resize', function() {
  var navbar = document.querySelector('.navbar');
  if (window.innerWidth <= 768) {
    navbar.classList.add('hidden');
  } else {
    navbar.classList.remove('hidden');
  }
});