ul{
  margin: 30px;
  padding: 0;
  li{
    list-style: none;
    line-height: 40px;
    padding: 0px 15px;
    border-radius: 5px;
    margin: 5px 0;
    transition: all 0.2s;
    color: grey;
  }
  li.active{
    background: red;
    color:#fff;
  }
}