.whatsapp-fixed-button {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 9999;
    width: 75px;
    height: 75px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.whatsapp-fixed-button a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 75px;
    height: 75px;
    font-size: 50px;
    color: #fff;
    background: #25d366;
    border-radius: 50%;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
    transition: box-shadow 0.2s, background 0.2s, color 0.2s;
    text-decoration: none;
}
.whatsapp-fixed-button a:hover {
    background: #fff;
    color: #25d366;
    box-shadow: 0 4px 16px rgba(0,0,0,0.25);
}
.whatsapp-fixed-button .fa-whatsapp {
    font-size: 50px;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}