.btn-wasap {
    display:block;
    width:70px;
    height:70px;
    color:#fff;
    position:fixed;
    right:20px;
    bottom:20px;
    border-radius:50%;
    line-height:80px;
    text-align:center;
    border:2px;
    border-color:darkgreen;
    z-index:999;
}