zdoc/assets/sass/components/_dropdown.scss

.dropdown {
  position: relative;
  display: inline-block;
  height: 100%;
}

.dropdown-content {
  display: none;
  position: absolute;
  z-index: z('dropdown');
}

.dropdown-content a {
  padding: 0.3rem 0.5rem;
  text-decoration: none;
  display: block;
  @include truncate2(120px);
}

.dropdown:hover .dropdown-content {
  display: block;
}