.dropdown {
  position: relative;
}

.submenu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: auto;
  z-index: 999;
  background-color: white;
  list-style: none;
  padding: 0;
  margin: 0;
  min-width: 200px;
  border: 1px solid #333;
}
.submenu a {
  color: gray;
  padding: 0.5rem 1rem;
  display: block;
  text-decoration: none;
}

.submenu a:hover {
  background-color: light-gray;
  color: black;
}

.dropdown:hover .submenu {
  display: block;
}

.submenu li {
  black-space: nowrap;
}
/* On large screens, switch to right-aligned submenu */
@media screen and (min-width: 60em) {
  .submenu {
    right: 0;
    left: auto;
  }
}