CSS3

.navbar .nav ul {
  border-radius: 4px;
  left: 0;
  list-style-type: none;
  margin-left: 0;
  opacity: 0;
  position: absolute;
  top: 0;
  width: 234px;
  -webkit-transform: scale(1, 0.99);
  -webkit-transform-origin: 0 0;
  visibility: hidden;
  -webkit-transition: 0.3s ease-out;
  -moz-transition: 0.3s ease-out;
  -o-transition: 0.3s ease-out;
  transition: 0.3s ease-out;
  -webkit-backface-visibility: hidden;
}