#myBtn {
    display: none;
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 99;
    border: none;
    outline: none;
    background-color: rgba(255,255,255,0.7);
    cursor: pointer;
    padding: 5px;
    border-radius: 4px;
}

#myBtn:hover {
    background-color: rgba(255,255,255,0.5);
}

@media only screen and (min-width: 768px) {
    #myBtn {
    bottom: 50px;
}
}