#mbw_boton_whatsapp {
    position: fixed;
    bottom: 50px;
    right: 20px;
    z-index: 100;
    text-align: right;
    max-width: 241px;
}

#mbw_boton_whatsapp a {
    width: 100%;
    display: inline-block;
}

#mbw_boton_whatsapp img {
    /* max-width: 35%; */
    height: auto;
}

@media (max-width: 768px) {
    #mbw_boton_whatsapp {
        bottom: 20px;
        left: 20px;
        text-align: left;
        max-width: 120px;
    }
    #mbw_boton_whatsapp img {
        max-width: 45%;
        height: auto;
    }
}