fix layout shifting during data load

src/components/Player.tsx

@@ -668,7 +668,7 @@ export default function Player({ playerData }: { playerData: ResourceType<Player
         </Popover>
     );
 
-    let einbettenText = `<div style="position:relative;padding-top:56.25%;"><iframe style="position:absolute;top:0;left:0;width:100%;height:100%;overflow: hidden;border: none;" src="${window.location.origin}${basePath}/${course.id_string}/${lecture.id}/embed" allowfullscreen="true"></iframe></div>`;
+    let einbettenText = `<div style="position:relative;padding-top:56.25%;"><iframe style="position:absolute;top:0;left:0;width:100%;height:100%;overflow: hidden;border: none;" src="${window.location.origin}${basePath}/${course.id_string}/${lecture.id}/embed" allowfullscreen="true" scrolling="no"></iframe></div>`;
     const einbettenCopy = () => {
         var copyText = document.getElementById("einbettenInput") as HTMLInputElement;
 

src/styles/globals.scss

@@ -275,3 +275,7 @@ $link-decoration: none;
 	width: 100%;
 	overflow-x: auto;
 }
+
+html {
+	overflow-y: scroll;
+}
\ No newline at end of file