Issue #2315885 by Gábor Hojtsy: Fixed Quickfix: language settings page seriously misaligned.

core/modules/content_translation/css/content_translation.admin.css

@@ -6,9 +6,6 @@
 #language-content-settings-form table .bundle {
   width: 24%;
 }
-#language-content-settings-form table td.bundle {
-  font-weight: bold;
-}
 #language-content-settings-form table .field {
   padding-left: 3em; /* LTR */
   width: 24%;

core/modules/language/css/language.admin.css

@@ -6,11 +6,6 @@
 #language-content-settings-form table .bundle {
   width: 25%;
 }
-
-#language-content-settings-form table td.bundle {
-  font-weight: bold;
-}
-
 #language-content-settings-form table .operations {
   width: 75%;
 }

core/modules/language/language.libraries.yml

-language.admin:
+drupal.language.admin:
   version: VERSION
   js:
     language.admin.js: {}
+  css:
+    theme:
+      css/language.admin.css: {}
   dependencies:
     - core/jquery
     - core/drupal

core/modules/language/src/Form/NegotiationConfigureForm.php

@@ -207,7 +207,7 @@ protected function configureFormTable(array &$form, $type)  {
         '#attributes' => array('class' => array('language-customization-checkbox')),
         '#attached' => array(
           'library' => array(
-            'language/language.admin'
+            'language/drupal.language.admin'
           ),
         ),
       );