如何在单击Bootstrap 4中的DropdownToggle列表时更改DropdownItem背景色

<div class="dropdown">
  <button class="btn btn-primary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown
  </button>
  <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
    <a class="dropdown-item" href="#">Item 1</a>
    <a class="dropdown-item" href="#">Item 2</a>
    <a class="dropdown-item" href="#">Item 3</a>
  </div>
</div>

.dropdown-item.custom-bg {
  background-color: #ff0000; /* 设置自定义的背景色 */
  color: #ffffff; /* 设置自定义的文本颜色 */
}

var dropdownToggle = document.querySelector('.dropdown-toggle');
var dropdownItems = document.querySelectorAll('.dropdown-item');

dropdownToggle.addEventListener('click', function() {
  dropdownItems.forEach(function(item) {
    item.classList.toggle('custom-bg');
  });
});

$('.dropdown-toggle').click(function() {
  $('.dropdown-item').toggleClass('custom-bg');
});