#myBtn {
    position: fixed;
    bottom: 50px;
    right: 25px;
    z-index: 99;
    border: none;
    outline: none;
    color: white;
    cursor: pointer;
    font-family: 'Work Sans', sans-serif;
}

#myBtn #whatsapp {
    width: 40px;
}

.footer {
    position: fixed;
    left: 0;
    bottom: 0;
    width: 100%;
    text-align: center;
    background-color: #fff;
    border-top: solid 1px #000;
}

@media only screen and (max-width: 600px) {
    #myBtn #whatsapp {
        width: 30px;
    }
}