.btn-wsp {
    position: fixed;
    width: 60px;
    height: 60px;
    bottom: 25px;
    left: 25px;
    background: #25d366;
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    box-shadow: 0px 1px 10px rgba(0,0,0,0.3);
    z-index: 100;
    transition: all 300ms ease;
    text-decoration: none;
}

.btn-wsp:hover {
    background: #20ba5a;
    transform: scale(1.08);
}

.whatsapp-icon {
    width: 38px;
    height: 38px;
}

@media only screen and (min-width: 320px) and (max-width: 768px) {
    .btn-wsp {
        width: 63px;
        height: 63px;
        bottom: 20px;
        right: 20px;
    }

    .whatsapp-icon {
        width: 40px;
        height: 40px;
    }
}