Thank you for your help. The first solution solved the problem on some apple devices, but not on all. I'm not sure thogh, if I implemented the pageCSS correctly, the HTML-Code is below. This is our pretest link:
https://www.soscisurvey.de/EmpraSoSe22/?act=I8N9wFN9flnVGpUOMSrocMIn
<p></p>
<Video id="Blume" width="512" height="288" controls >
<source src="Blume.mp4" type="video/mp4">
</video>
<script type="text/javascript">
<!--
var video = document.getElementById("Blume");
// Bedienelemente ausblenden, sobald es abspielt
SoSciTools.attachEvent(video, "play", function(evt) {
document.getElementById("Blume").removeAttribute("controls");
});
// Weiter-Knopf ausblenden
SoSciTools.attachEvent(window, "load", function(evt) {
SoSciTools.submitButtonsHide();
});
// -->
</script>
<script>
var aud = document.getElementById("Blume");
aud.addEventListener("ended", function() {SoSciTools.submitPage()});
</script>
<style>
pageCSS( '*::-webkit-media-controls {
display: none!important;
-webkit-appearance: none;
}');
</style>