.b4wc-booking-fields {
    background: #f9f9f9;
    padding: 15px;
    border: 1px solid #e2e2e2;
    border-radius: 6px;
}
.b4wc-booking-fields select, 
.b4wc-booking-fields input[type="date"] {
    width: 100%;
    padding: 8px;
    margin-top: 5px;
}