#whatsapp-button {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1000;
    width: 60px;
    height: 60px;
    background-color: #25d366;
    border-radius: 50%;
    text-align: center;
    box-shadow: 2px 2px 5px rgba(0,0,0,0.3);
}

#whatsapp-button a {
    display: block;
    width: 100%;
    height: 100%;
    color: #ffffff;
    font-size: 30px;
    line-height: 60px;
}

#whatsapp-button a:hover {
    color: #ffffff;
}