diff -r 3d4e9c994f10 -r a86126ab1dd4 wp/wp-includes/js/mediaelement/wp-mediaelement.css
--- a/wp/wp-includes/js/mediaelement/wp-mediaelement.css	Tue Oct 22 16:11:46 2019 +0200
+++ b/wp/wp-includes/js/mediaelement/wp-mediaelement.css	Tue Dec 15 13:49:49 2020 +0100
@@ -67,9 +67,9 @@
 	overflow: visible;
 }
 
-.media-embed-details .embed-media-settings .setting span {
-	max-width: 400px;
-	width: auto;
+.media-embed-details .embed-media-settings .setting span:not(.button-group) {
+	max-width: 400px; /* Back-compat for pre-5.3 */
+	width: auto; /* Back-compat for pre-5.3 */
 }
 
 .media-embed-details .embed-media-settings .checkbox-setting span {
@@ -94,7 +94,7 @@
 }
 
 .media-embed-details .setting .remove-setting {
-	padding: 0;
+	padding: 5px 0;
 }
 
 .media-embed-details .setting a:hover {