diff --git a/core/modules/ckeditor/js/ckeditor.js b/core/modules/ckeditor/js/ckeditor.js
index f67ed62..a3891ab 100644
--- a/core/modules/ckeditor/js/ckeditor.js
+++ b/core/modules/ckeditor/js/ckeditor.js
@@ -224,6 +224,7 @@
       classes.push('editor-dialog');
       dialogSettings.dialogClass = classes.join(' ');
       dialogSettings.autoResize = Drupal.checkWidthBreakpoint(600);
+      dialogSettings.width = '95%';
 
       // Add a "Loading…" message, hide it underneath the CKEditor toolbar,
       // create a Drupal.Ajax instance to load the dialog and trigger it.
diff --git a/core/modules/editor/css/editor.css b/core/modules/editor/css/editor.css
index 9d1c660..3d4f257 100644
--- a/core/modules/editor/css/editor.css
+++ b/core/modules/editor/css/editor.css
@@ -3,14 +3,8 @@
  * Styles for text editors.
  */
 
-.editor-dialog {
-  /* This !important is required to override inline CSS of jQuery UI. */
-  width: 80% !important;
-  max-width: 500px;
-}
-
-@media screen and (max-width: 600px) {
+@media screen and (min-width: 600px) {
   .editor-dialog {
-    width: 95% !important;
+    max-width: 500px;
   }
-}
+}
\ No newline at end of file