#whatsapp {
    position: fixed;
    bottom: 20px;
    left:20px;
    z-index: 200;
 }

 svg {
    width: 80px;
    filter: drop-shadow(0 1px 4px rgba(0,0,0,.4));
 }

 circle {
    fill: #25d366;
 }
 path {
    fill: #fff;
 }