使导航栏文本在使用CSS滚动时更改颜色

<nav>
  <ul>
    <li><a href="#">Home</a></li>
    <li><a href="#">About</a></li>
    <li><a href="#">Services</a></li>
    <li><a href="#">Contact</a></li>
  </ul>
</nav>

nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: #fff;
  padding: 10px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

nav ul {
  display: flex;
  justify-content: space-between;
  list-style: none;
  margin: 0;
  padding: 0;
}

nav ul li {
  margin-right: 10px;
}

nav ul li a {
  color: #333;
  text-decoration: none;
}

.nav-scroll {
  color: #fff;
  background-color: #333;
}

window.addEventListener('scroll', function() {
  var nav = document.querySelector('nav');
  var navItems = document.querySelectorAll('nav ul li a');

  if (window.scrollY > 100) {
    nav.classList.add('nav-scroll');
    navItems.forEach(function(item) {
      item.style.color = '#fff';
    });
  } else {
    nav.classList.remove('nav-scroll');
    navItems.forEach(function(item) {
      item.style.color = '#333';
    });
  }
});