Index: src/wp-admin/css/media.css
===================================================================
--- src/wp-admin/css/media.css	(revision 46758)
+++ src/wp-admin/css/media.css	(working copy)
@@ -859,6 +859,12 @@
 	width: 250px;
 }
 
+.wp_attachment_holder .imgedit-wrap .imgedit-panel-content,
+.wp_attachment_holder .imgedit-wrap .imgedit-menu {
+	min-width: 400px;
+	max-width: calc( 100% - 266px );
+}
+
 .imgedit-settings input {
 	margin-top: 0;
 	vertical-align: middle;
@@ -1203,11 +1209,24 @@
 		font-size: 16px;
 		padding: 6px 10px;
 	}
+}
 
+@media screen and (min-width: 783px) and (max-width: 1400px) {
 	.wp_attachment_holder .imgedit-wrap .imgedit-panel-content,
-	.wp_attachment_holder .imgedit-wrap .imgedit-settings {
+	.wp_attachment_holder .imgedit-wrap .imgedit-menu {
+		min-width: 300px;
+		max-width: calc( 100% - 266px );
+	}
+}
+
+@media screen and (min-width: 320px) and (max-width: 782px) {
+	.wp_attachment_holder .imgedit-wrap .imgedit-panel-content,
+	.wp_attachment_holder .imgedit-wrap .imgedit-settings,
+	.wp_attachment_holder .imgedit-wrap .imgedit-menu {
 		float: none;
 		width: auto;
+		min-width: initial;
+		max-width: initial;
 	}
 }