Make wpuf form fields stack in single line in responsive mode

/* Make wpuf form fields stack in single line in responsive mode */
@media (max-width: 767px){
body ul.wpuf-form li {
    margin-left: 0;
    margin-bottom: 4px;
    padding: 10px;
    box-sizing: content-box !important;
    }

body .wpuf-col-half, body .wpuf-col-half-last {
    width: 84% !important;
    float: left !important;
}

textarea {
    max-width: 90% !important;
    }
}