Stylish <a> Styling - Adding animation effect

stylish-a-styling_04.less

@linkBlue: #0000ee;
a {
  color: @linkBlue;
  display: inline-block;
  position: relative;
  text-decoration: none;
  &:before {
    background-color: @linkBlue;
    content: '';
    height: 2px;
    position: absolute;
    bottom: -1px;
    transition: width 0.3s ease-in-out;
    width: 100%;
  }
  &:hover {
    &:before {
       width: 0;
    }
  }
}