a {
      position: relative;
      &:after {
        content: '';
        position: absolute;
        width: 0;
        height: 3px;
        display: block;
        margin-top: 2px;
        left: 0;
        transition: width .5s ease;
        -webkit-transition: width .5s ease;
      }
      &:hover:after {
        width: 100%;
        right: 0;
        background: $charcoal;
      }
    }