.my-float{
    position: fixed;
    right: 18px;
    bottom: 100px;
    font-size: 44px;
    z-index: 100;
    width: 65px;
    height: 65px;
    border-radius: 50%;
    background-color: #25D366;
    text-align: center;
    padding: 0px;
    color: #fff;
}

.my-float:hover {
    background-color: #000;
}