.btn {
    padding: 10px 20px;
    background: yellow;
    color: #111111;
    border-bottom: solid 5px gray;
    border-radius: 4px;
    font-size:2em
   }
   .btn:active {
    -webkit-transform: translateY(5px);
    transform: translateY(5px);
    border-bottom: none;
   }