@media (max-width:768px){

.mphb-booking-form input[type=submit],
.mphb-booking-form button,
.mphb_sc_booking_form-wrapper input[type=submit]{

    width:100% !important;
    height:auto !important;

    padding:14px 18px !important;

    white-space:normal !important;
    line-height:1.3;
    text-align:center;

    font-size:14px;
}

}