#myBtn {
    display: none;
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 99;
    border: none;
    outline: none;
    background-color: rgb(52, 58, 64);
    color: white;
    cursor: pointer;
    padding: 10px 15px;
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, .3);
    -webkit-border-radius: 10px;
    -moz-border-radius: 10px;
    -ms-border-radius: 10px;
    -o-border-radius: 10px;
}

#myBtn:hover {
    background-color: rgba(52, 58, 64, .9);
}