Kartra Horizontal Form - External Embed

<style>
#kartra_optin_form_fields_container { display: flex; flex-wrap: wrap; }
#kartra_optin_form_fields_container > div { flex: 100 0; margin-right: 10px; min-width: 250px; }
#kartra_optin_form_fields_container > button { flex: 1 1 auto; margin-top: 0; width: auto !important; }
#kartra_optin_form_fields_container .js_gdpr_wrapper { min-width: 100%; padding-bottom: 20px; }
#kartra_optin_form_fields_container > button { height: 70px; }
@media only screen and (max-width: 736px) {
  #kartra_optin_form_fields_container > button { height: 60px; padding: 15px 24px; }
}
@media only screen and (max-width: 556px) {
  #kartra_optin_form_fields_container > button { height: 50px; padding: 10px 24px; }
}
</style>
<script>
(function () {
function reflexForm () {
var koffc = document.getElementById('kartra_optin_form_fields_container'),
    gdprw = document.getElementsByClassName('js_gdpr_wrapper'),
    sbtn = document.getElementsByClassName('kartra_optin_submit_btn');
    koffc.append(gdprw[0], sbtn[0]);
}
if (window.addEventListener) window.addEventListener('load', reflexForm, false);
else if (window.attachEvent) window.attachEvent('onload', reflexForm);
})();
</script>