diff --git a/core/modules/block/block.admin.css b/core/modules/block/block.admin.css
deleted file mode 100644
index 831ad44..0000000
--- a/core/modules/block/block.admin.css
+++ /dev/null
@@ -1,33 +0,0 @@
-#blocks tr.region-title td {
-  font-weight: bold;
-}
-#blocks tr.region-message {
-  font-weight: normal;
-  color: #999;
-}
-#blocks tr.region-populated {
-  display: none;
-}
-.block-region {
-  background-color: #ff6;
-  margin-top: 4px;
-  margin-bottom: 4px;
-  padding: 3px;
-}
-a.block-demo-backlink,
-a.block-demo-backlink:link,
-a.block-demo-backlink:visited {
-  background-color: #b4d7f0;
-  border-radius: 0 0 10px 10px;
-  color: #000;
-  font-family: "Lucida Grande", Verdana, sans-serif;
-  font-size: small;
-  line-height: 20px;
-  left: 20px; /*LTR*/
-  padding: 5px 10px;
-  position: fixed;
-  z-index: 499;
-}
-a.block-demo-backlink:hover {
-  text-decoration: underline;
-}
diff --git a/core/modules/block/block.admin.inc b/core/modules/block/block.admin.inc
index 6774119..0297cba 100644
--- a/core/modules/block/block.admin.inc
+++ b/core/modules/block/block.admin.inc
@@ -13,7 +13,8 @@
  * @see block_menu()
  */
 function block_admin_demo($theme = NULL) {
-  drupal_add_css(drupal_get_path('module', 'block') . '/block.admin.css');
+  drupal_add_css(drupal_get_path('module', 'block') . '/css/block.admin.css');
+  drupal_add_css(drupal_get_path('module', 'block') . '/css/block.admin.skin.css');
   return '';
 }
 
diff --git a/core/modules/block/lib/Drupal/block/BlockListController.php b/core/modules/block/lib/Drupal/block/BlockListController.php
index 5dd981f..4022633 100644
--- a/core/modules/block/lib/Drupal/block/BlockListController.php
+++ b/core/modules/block/lib/Drupal/block/BlockListController.php
@@ -106,7 +106,8 @@ public function getFormID() {
    */
   public function buildForm(array $form, array &$form_state) {
     $entities = $this->load();
-    $form['#attached']['css'][] = drupal_get_path('module', 'block') . '/block.admin.css';
+    $form['#attached']['css'][] = drupal_get_path('module', 'block') . '/css/block.admin.css';
+    $form['#attached']['css'][] = drupal_get_path('module', 'block') . '/css/block.admin.skin.css';
     $form['#attached']['library'][] = array('system', 'drupal.tableheader');
     $form['#attached']['library'][] = array('block', 'drupal.block');
 
diff --git a/core/modules/color/color.admin-rtl.css b/core/modules/color/color.admin-rtl.css
deleted file mode 100644
index d5bfbe8..0000000
--- a/core/modules/color/color.admin-rtl.css
+++ /dev/null
@@ -1,48 +0,0 @@
-/**
- * @file
- * Right-to-left specific stylesheet for the Color module.
- */
-
-#placeholder {
-  left: 0;
-  right: auto;
-}
-
-/* Palette */
-.color-form .form-item {
-  padding-left: 0;
-  padding-right: 1em;
-}
-.color-form label {
-  float: right;
-  clear: right;
-}
-.color-form .form-text,
-.color-form .form-select {
-  float: right;
-}
-.color-form .form-text {
-  margin-right: 0;
-  margin-left: 5px;
-}
-#palette .hook {
-  float: right;
-}
-#palette .down,
-#palette .up,
-#palette .both {
-  background: url(images/hook-rtl.png) no-repeat 0 0;
-}
-#palette .up {
-  background-position: 0 -27px;
-}
-#palette .both {
-  background-position: 0 -54px;
-}
-#palette .lock {
-  float: right;
-  right: -10px;
-}
-.js #preview {
-  float: right;
-}
diff --git a/core/modules/color/color.admin.css b/core/modules/color/color.admin.css
deleted file mode 100644
index e9aee91..0000000
--- a/core/modules/color/color.admin.css
+++ /dev/null
@@ -1,85 +0,0 @@
-/**
- * @file
- * Stylesheet for the administration pages of the Color module.
- */
-
-/* Farbtastic placement */
-.color-form {
-  max-width: 50em;
-  position: relative;
-}
-#placeholder {
-  position: absolute;
-  top: 0;
-  right: 0; /* LTR */
-}
-
-/* Palette */
-.color-form .form-item {
-  height: 2em;
-  line-height: 2em;
-  padding-left: 1em; /* LTR */
-  margin: 0.5em 0;
-}
-.color-form label {
-  float: left; /* LTR */
-  clear: left; /* LTR */
-  width: 10em;
-}
-.color-form .form-text,
-.color-form .form-select {
-  float: left; /* LTR */
-}
-.color-form .form-text {
-  text-align: center;
-  margin-right: 5px; /* LTR */
-  cursor: pointer;
-}
-
-#palette .hook {
-  float: left; /* LTR */
-  margin-top: 3px;
-  width: 16px;
-  height: 16px;
-}
-#palette .down,
-#palette .up,
-#palette .both {
-  background: url(images/hook.png) no-repeat 100% 0; /* LTR */
-}
-#palette .up {
-  background-position: 100% -27px; /* LTR */
-}
-#palette .both {
-  background-position: 100% -54px; /* LTR */
-}
-
-#palette .lock {
-  float: left; /* LTR */
-  position: relative;
-  top: -1.4em;
-  left: -10px; /* LTR */
-  width: 20px;
-  height: 25px;
-  background: url(images/lock.png) no-repeat 50% 2px;
-  cursor: pointer;
-}
-#palette .unlocked {
-  background-position: 50% -22px;
-}
-#palette .form-item {
-  width: 20em;
-}
-#palette .item-selected {
-  background: #eee;
-}
-
-/* Preview */
-#preview {
-  display: none;
-}
-.js #preview {
-  display: block;
-  position: relative;
-  float: left; /* LTR */
-}
diff --git a/core/modules/color/color.module b/core/modules/color/color.module
index 2203133..40fb364 100644
--- a/core/modules/color/color.module
+++ b/core/modules/color/color.module
@@ -194,7 +194,8 @@ function color_scheme_form($complete_form, &$form_state, $theme) {
       ),
       // Add custom CSS.
       'css' => array(
-        $base . '/color.admin.css' => array(),
+        $base . '/css/color.admin.css' => array(),
+        $base . '/css/color.admin.skin.css' => array(),
       ),
       // Add custom JavaScript.
       'js' => array(
diff --git a/core/modules/dblog/dblog-rtl.css b/core/modules/dblog/dblog-rtl.css
deleted file mode 100644
index 7326fa8..0000000
--- a/core/modules/dblog/dblog-rtl.css
+++ /dev/null
@@ -1,9 +0,0 @@
-/**
- * @file
- * Right-to-Left styling for the Database Logging module.
- */
-
-.dblog-filter-form .form-item-type,
-.dblog-filter-form .form-item-severity {
-  margin: .1em .1em .1em .9em;
-}
diff --git a/core/modules/dblog/dblog.css b/core/modules/dblog/dblog.css
deleted file mode 100644
index 5494553..0000000
--- a/core/modules/dblog/dblog.css
+++ /dev/null
@@ -1,47 +0,0 @@
-/**
- * @file
- * Admin styles for the Database Logging module.
- */
-
-.dblog-filter-form .form-item-type,
-.dblog-filter-form .form-item-severity {
-  display: inline-block;
-  margin: .1em .9em .1em .1em; /* LTR */
-  max-width: 30%;
-}
-.dblog-filter-form .form-actions {
-  display: inline-block;
-  padding: 3ex 0 0;
-  vertical-align: top;
-}
-.dblog-user.odd .active {
-  background: #ddf;
-}
-.dblog-user.even .active {
-  background: #cce;
-}
-.dblog-error.odd .active {
-  background: #ffc9c9;
-}
-.dblog-error.even .active {
-  background: #eeb9b9;
-}
-.dblog-warning.odd .active {
-  background: #fffdca;
-}
-.dblog-warning.even .active {
-  background: #eeedbd;
-}
-.admin-dblog .icon {
-  background: no-repeat center;
-  width: 16px;
-}
-.admin-dblog .dblog-warning .icon {
-  background-image: url(../../misc/message-16-warning.png);
-}
-.admin-dblog .dblog-error .icon,
-.admin-dblog .dblog-critical .icon,
-.admin-dblog .dblog-alert .icon,
-.admin-dblog .dblog-emergency .icon {
-  background-image: url(../../misc/message-16-error.png);
-}
diff --git a/core/modules/dblog/dblog.module b/core/modules/dblog/dblog.module
index d28f3b7..bf12a33 100644
--- a/core/modules/dblog/dblog.module
+++ b/core/modules/dblog/dblog.module
@@ -90,7 +90,8 @@ function dblog_menu() {
  */
 function dblog_page_build(&$page) {
   if (arg(0) == 'admin' && arg(1) == 'reports') {
-    $page['#attached']['css'][] = drupal_get_path('module', 'dblog') . '/dblog.css';
+    $page['#attached']['css'][] = drupal_get_path('module', 'dblog') . '/css/dblog.admin.css';
+    $page['#attached']['css'][] = drupal_get_path('module', 'dblog') . '/css/dblog.admin.skin.css';
   }
 }
 
diff --git a/core/modules/entity_reference/css/entity_reference-rtl.admin.css b/core/modules/entity_reference/css/entity_reference-rtl.admin.css
deleted file mode 100644
index 3302ab8..0000000
--- a/core/modules/entity_reference/css/entity_reference-rtl.admin.css
+++ /dev/null
@@ -1,4 +0,0 @@
-
-.entity_reference-settings {
-  margin-right: 1.5em;
-}
diff --git a/core/modules/field_ui/field_ui.admin-rtl.css b/core/modules/field_ui/field_ui.admin-rtl.css
deleted file mode 100644
index 3b50ab3..0000000
--- a/core/modules/field_ui/field_ui.admin-rtl.css
+++ /dev/null
@@ -1,9 +0,0 @@
-/**
- * @file
- * Right-to-left specific stylesheet for the Field UI module.
- */
-
-/* 'Manage fields' overview */
-.field-ui-overview .add-new .label-input {
-  float: right;
-}
diff --git a/core/modules/field_ui/field_ui.admin.css b/core/modules/field_ui/field_ui.admin.css
deleted file mode 100644
index cf59695..0000000
--- a/core/modules/field_ui/field_ui.admin.css
+++ /dev/null
@@ -1,68 +0,0 @@
-/**
- * @file
- * Stylesheet for the Field UI module.
- */
-
-/* 'Manage fields' and 'Manage display' overviews */
-.field-ui-overview .add-new .label-input {
-  float: left; /* LTR */
-}
-.field-ui-overview .add-new .tabledrag-changed {
-  display: none;
-}
-.field-ui-overview .add-new .description {
-  margin-bottom: 0;
-  max-width: 250px;
-}
-.field-ui-overview .add-new .form-type-machine-name .description {
-  white-space: normal;
-}
-.field-ui-overview .add-new .add-new-placeholder {
-  font-weight: bold;
-  padding-bottom: .5em;
-}
-.field-ui-overview .region-title td {
-  font-weight: bold;
-}
-.field-ui-overview .region-message td {
-  font-style: italic;
-}
-.field-ui-overview .region-populated {
-  display: none;
-}
-.field-ui-overview .region-add-new-title {
-  display: none;
-}
-.field-ui-overview .add-new td {
-  vertical-align: top;
-  white-space: nowrap;
-}
-
-/* 'Manage display' overview */
-.field-ui-overview .field-formatter-summary-cell {
-  line-height: 1em;
-}
-.field-ui-overview .field-formatter-summary {
-  float: left;
-  font-size: .9em;
-}
-.field-ui-overview .field-formatter-summary-cell .warning {
-  display: block;
-  float: left;
-  margin-right: .5em;
-}
-.field-ui-overview .field-formatter-settings-edit-wrapper {
-  float: right;
-}
-.field-ui-overview .field-formatter-settings-edit {
-  float: right;
-}
-.field-ui-overview .field-formatter-settings-editing td {
-  vertical-align: top;
-}
-.field-ui-overview .field-formatter-settings-editing .field-formatter-type {
-  display: none;
-}
-.field-ui-overview .field-formatter-settings-edit-form .formatter-name{
-  font-weight: bold;
-}
diff --git a/core/modules/field_ui/field_ui.module b/core/modules/field_ui/field_ui.module
index 2c50450..281c7a6 100644
--- a/core/modules/field_ui/field_ui.module
+++ b/core/modules/field_ui/field_ui.module
@@ -345,7 +345,8 @@ function field_ui_library_info() {
       drupal_get_path('module', 'field_ui') . '/field_ui.js' => array(),
     ),
     'css' => array(
-      drupal_get_path('module', 'field_ui') . '/field_ui.admin.css' => array(),
+      drupal_get_path('module', 'field_ui') . '/css/field_ui.admin.css' => array(),
+      drupal_get_path('module', 'field_ui') . '/css/field_ui.admin.skin.css' => array(),
     ),
     'dependencies' => array(
       array('system', 'jquery'),
diff --git a/core/modules/file/file.admin.css b/core/modules/file/file.admin.css
deleted file mode 100644
index 24f90e1..0000000
--- a/core/modules/file/file.admin.css
+++ /dev/null
@@ -1,26 +0,0 @@
-
-/**
- * @file
- * Admin stylesheet for file module.
- */
-
-/**
- * File upload widget.
- */
-.form-managed-file .form-file,
-.form-managed-file .form-submit {
-  margin: 0;
-}
-.form-managed-file .progress-disabled {
-  display: inline;
-  float: none;
-}
-.form-managed-file div.ajax-progress-bar {
-  display: none;
-  margin-top: 4px;
-  padding: 0;
-  width: 28em;
-}
-.form-managed-file div.ajax-progress-bar .bar {
-  margin: 0;
-}
diff --git a/core/modules/file/file.module b/core/modules/file/file.module
index 3fcd034..1c20279 100644
--- a/core/modules/file/file.module
+++ b/core/modules/file/file.module
@@ -1658,7 +1658,7 @@ function file_library_info() {
       drupal_get_path('module', 'file') . '/file.js' => array(),
     ),
     'css' => array(
-      drupal_get_path('module', 'file') . '/file.admin.css'
+      drupal_get_path('module', 'file') . '/css/file.admin.css'
     ),
     'dependencies' => array(
       array('system', 'jquery'),
diff --git a/core/modules/filter/filter.admin-rtl.css b/core/modules/filter/filter.admin-rtl.css
deleted file mode 100644
index 4d972e2..0000000
--- a/core/modules/filter/filter.admin-rtl.css
+++ /dev/null
@@ -1,23 +0,0 @@
-
-/**
- * @file
- * Right-to-Left administrative styling for the Filter module.
- */
-
-/**
- * Filter information under field.
- */
-.filter-help {
-  float: left;
-}
-.filter-help a {
-  background-position: left center;
-  padding: 0 0 0 20px;
-}
-
-/**
- * Improve filter tips position.
- */
-.tips {
-  padding-right: 0;
-}
diff --git a/core/modules/filter/filter.admin.css b/core/modules/filter/filter.admin.css
deleted file mode 100644
index 8c144cf..0000000
--- a/core/modules/filter/filter.admin.css
+++ /dev/null
@@ -1,54 +0,0 @@
-
-/**
- * @file
- * Admin styling for the Filter module.
- */
-
-/**
- * Filter information under field.
- */
-.text-format-wrapper > .form-item {
-  margin-bottom: 0;
-}
-
-.filter-wrapper {
-  border: 1px solid #ccc;
-  border-top: 0;
-  margin: 0;
-  padding: 0.5em 1.5em;
-}
-.filter-wrapper .form-item {
-  margin-top: 0;
-}
-.filter-wrapper .form-item label {
-  display: inline;
-}
-
-.filter-help {
-  float: right; /* LTR */
-}
-.filter-help p {
-  margin: 0;
-}
-.filter-help a {
-  background: transparent url(../../misc/help.png) right center no-repeat; /* LTR */
-  padding: 0 20px 0 0; /* LTR */
-}
-
-.text-format-wrapper .description {
-  margin-top: 0.5em;
-}
-.tips {
-  font-size: 0.9em;
-  margin-bottom: 0;
-  margin-top: 0;
-  padding-bottom: 0;
-  padding-top: 0;
-}
-
-/**
- * Improve filter tips position.
- */
-.tips {
-  padding-left: 0; /* LTR */
-}
diff --git a/core/modules/filter/filter.module b/core/modules/filter/filter.module
index 57ff8c2..2fb5403 100644
--- a/core/modules/filter/filter.module
+++ b/core/modules/filter/filter.module
@@ -1811,7 +1811,8 @@ function filter_library_info() {
       drupal_get_path('module', 'filter') . '/filter.admin.js' => array(),
     ),
     'css' => array(
-      drupal_get_path('module', 'filter') . '/filter.admin.css'
+      drupal_get_path('module', 'filter') . '/css/filter.admin.css',
+      drupal_get_path('module', 'filter') . '/css/filter.admin.skin.css',
     ),
     'dependencies' => array(
       array('system', 'jquery'),
@@ -1827,7 +1828,8 @@ function filter_library_info() {
       drupal_get_path('module', 'filter') . '/filter.js' => array(),
     ),
     'css' => array(
-      drupal_get_path('module', 'filter') . '/filter.admin.css'
+      drupal_get_path('module', 'filter') . '/css/filter.admin.css',
+      drupal_get_path('module', 'filter') . '/css/filter.admin.skin.css',
     ),
     'dependencies' => array(
       array('system', 'jquery'),
diff --git a/core/modules/help/help-rtl.css b/core/modules/help/help-rtl.css
deleted file mode 100644
index 035d5d2..0000000
--- a/core/modules/help/help-rtl.css
+++ /dev/null
@@ -1,10 +0,0 @@
-
-.help-items {
-  float: right;
-  margin-right: 0;
-  margin-left: 3%;
-}
-.help-items-last {
-  margin-right: 0;
-  margin-left: 0;
-}
diff --git a/core/modules/help/help.admin.inc b/core/modules/help/help.admin.inc
index a3bea9e..69c406a 100644
--- a/core/modules/help/help.admin.inc
+++ b/core/modules/help/help.admin.inc
@@ -12,7 +12,7 @@
  */
 function help_main() {
   // Add CSS.
-  drupal_add_css(drupal_get_path('module', 'help') . '/help.css');
+  drupal_add_css(drupal_get_path('module', 'help') . '/css/help.admin.css');
   $output = '<h2>' . t('Help topics') . '</h2><p>' . t('Help is available on the following items:') . '</p>' . help_links_as_list();
   return $output;
 }
diff --git a/core/modules/help/help.css b/core/modules/help/help.css
deleted file mode 100644
index 5d074c8..0000000
--- a/core/modules/help/help.css
+++ /dev/null
@@ -1,20 +0,0 @@
-
-.help-items {
-  float: left; /* LTR */
-  width: 22%;
-  margin-right: 3%; /* LTR */
-}
-.help-items-last {
-  margin-right: 0; /* LTR */
-}
-
-/**
- * Avoid text overlapping on a narrow viewport.
- */
-@media screen and (max-width: 480px) {
-  .help-items {
-    float: none;
-    width: 100%;
-    margin: 0;
-  }
-}
diff --git a/core/modules/help/lib/Drupal/help/Tests/HelpTest.php b/core/modules/help/lib/Drupal/help/Tests/HelpTest.php
index 54b955f..92a9cc6 100644
--- a/core/modules/help/lib/Drupal/help/Tests/HelpTest.php
+++ b/core/modules/help/lib/Drupal/help/Tests/HelpTest.php
@@ -67,7 +67,7 @@ public function testHelp() {
     // Check for css on admin/help.
     $this->drupalLogin($this->adminUser);
     $this->drupalGet('admin/help');
-    $this->assertRaw(drupal_get_path('module', 'help') . '/help.css', 'The help.css file is present in the HTML.');
+    $this->assertRaw(drupal_get_path('module', 'help') . '/css/help.admin.css', 'The help.css file is present in the HTML.');
 
     // Verify that introductory help text exists, goes for 100% module coverage.
     $this->assertRaw(t('For more information, refer to the specific topics listed in the next section or to the <a href="@drupal">online Drupal handbooks</a>.', array('@drupal' => 'http://drupal.org/documentation')), 'Help intro text correctly appears.');
diff --git a/core/modules/language/language.admin.css b/core/modules/language/language.admin.css
deleted file mode 100644
index 2af92d7..0000000
--- a/core/modules/language/language.admin.css
+++ /dev/null
@@ -1,16 +0,0 @@
-/**
- * @file
- * Styles for the content language administration page.
- */
-
-#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%;
-}
diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index f59fb38..7c2213b 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -803,7 +803,7 @@ function language_content_settings_form(array $form, array $form_state, array $s
   $form = array(
     '#labels' => $labels,
     '#attached' => array(
-      'css' => array($path . '/language.admin.css'),
+      'css' => array($path . '/css/language.admin.css'),
     ),
   );
 
diff --git a/core/modules/layout/layout.admin.css b/core/modules/layout/layout.admin.css
deleted file mode 100644
index 6e38bf4..0000000
--- a/core/modules/layout/layout.admin.css
+++ /dev/null
@@ -1,17 +0,0 @@
-.layout-display {
-  background: rgb(224, 224, 224);
-}
-
-.layout-region-demonstration {
-  background-image: -moz-linear-gradient(bottom, rgb(70,70,71) 40%, rgb(91,91,94) 70%, rgb(125,124,125) 88%);
-  background-image: -o-linear-gradient(bottom, rgb(70,70,71) 40%, rgb(91,91,94) 70%, rgb(125,124,125) 88%);
-  background-image: -ms-linear-gradient(bottom, rgb(70,70,71) 40%, rgb(91,91,94) 70%, rgb(125,124,125) 88%);
-  background-image: -webkit-linear-gradient(bottom, rgb(70,70,71) 40%, rgb(91,91,94) 70%, rgb(125,124,125) 88%);
-  background-image: -webkit-gradient(linear, left bottom, left top, color-stop(0.4, rgb(70,70,71)), color-stop(0.7, rgb(91,91,94)), color-stop(0.88, rgb(125,124,125)));
-  background-image: linear-gradient(bottom, rgb(70,70,71) 40%, rgb(91,91,94) 70%, rgb(125,124,125) 88%);
-  color: white;
-  font-size: 0.8em;
-  margin: 3px;
-  padding: 10px;
-  text-transform: uppercase;
-}
diff --git a/core/modules/layout/layout.admin.inc b/core/modules/layout/layout.admin.inc
index 9a1a921..40b70c2 100644
--- a/core/modules/layout/layout.admin.inc
+++ b/core/modules/layout/layout.admin.inc
@@ -70,6 +70,7 @@ function layout_page_view($key) {
     '#type' => 'markup',
     '#markup' => $instance->renderLayout(TRUE, $regions),
   );
-  $build['#attached']['css'][] = drupal_get_path('module', 'layout') . '/layout.admin.css';
+  $build['#attached']['css'][] = drupal_get_path('module', 'layout') . '/css/layout.admin.css';
+  $build['#attached']['css'][] = drupal_get_path('module', 'layout') . '/css/layout.admin.skin.css';
   return $build;
 }
diff --git a/core/modules/locale/locale.admin-rtl.css b/core/modules/locale/locale.admin-rtl.css
deleted file mode 100644
index 0b78f1b..0000000
--- a/core/modules/locale/locale.admin-rtl.css
+++ /dev/null
@@ -1,16 +0,0 @@
-/**
- * @file
- * CSS for the Locale module for right-to-left languages.
- */
-
-.locale-translate-filter-form .form-item-langcode,
-.locale-translate-filter-form .form-item-translation,
-.locale-translate-filter-form .form-item-customized {
-  float: right;
-  margin-left: 1em;
-  margin-right: 0;
-}
-.locale-translate-filter-form .form-actions {
-  float: right;
-  padding: 3.5ex 0 0 0;
-}
diff --git a/core/modules/locale/locale.admin.css b/core/modules/locale/locale.admin.css
deleted file mode 100644
index 03ce7bd..0000000
--- a/core/modules/locale/locale.admin.css
+++ /dev/null
@@ -1,123 +0,0 @@
-.locale-translate-filter-form .details-wrapper {
-  overflow: hidden;
-}
-.locale-translate-filter-form .form-item-langcode,
-.locale-translate-filter-form .form-item-translation,
-.locale-translate-filter-form .form-item-customized {
-  float: left; /* LTR */
-  margin-right: 1em; /* LTR */
-  margin-bottom: 0;
-  /**
-   * In Opera 9, DOM elements with the property of "overflow: auto"
-   * will partially hide its contents with unnecessary scrollbars when
-   * its immediate child is floated without an explicit width set.
-   */
-  width: 15em;
-}
-.locale-translate-filter-form .form-type-select select {
-  width: 100%;
-}
-.locale-translate-filter-form .form-actions {
-  float: left; /* LTR */
-  padding: 3.8ex 0 0 0; /* LTR */
-}
-.locale-translate-edit-form th {
-  width: 50%;
-  table-layout: fixed;
-}
-.locale-translate-edit-form .form-item {
-  white-space: normal;
-}
-.locale-translate-edit-form td {
-  vertical-align: top
-}
-
-.locale-translate-edit-form .changed {
-  background: #ffb;
-}
-
-.locale-translate-edit-form tr .form-type-item .ajax-changed {
-  position: absolute;
-}
-
-.locale-translate-filter-form .form-wrapper {
-  margin-bottom:0;
-}
-
-.locale-translate-edit-form table.changed {
-  margin-top: 0;
-}
-
-/**
- * Available translation updates page.
- */
-#locale-translation-status-form table {
-  table-layout: fixed;
-}
-#locale-translation-status-form th.select-all {
-  width: 4%;
-}
-#locale-translation-status-form th.title {
-  width: 25%;
-}
-#locale-translation-status-form th.description {
-}
-#locale-translation-status-form td {
-  vertical-align: top;
-}
-#locale-translation-status-form .expand .inner {
-  background: transparent url(../../misc/menu-collapsed.png) left .6em no-repeat;
-  margin-left: -12px;
-  padding-left: 12px;
-}
-#locale-translation-status-form .expanded .expand .inner {
-  background: transparent url(../../misc/menu-expanded.png) left .6em no-repeat;
-}
-
-#locale-translation-status-form label {
-  color: #1d1d1d;
-  font-size: 1.15em;
-}
-#locale-translation-status-form .description {
-  cursor: pointer;
-}
-#locale-translation-status-form .description .inner {
-  color: #5c5c5b;
-  line-height: 20px;
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
-}
-#locale-translation-status-form .expanded .description .inner {
-  height: auto;
-  overflow: visible;
-  white-space: normal;
-}
-#locale-translation-status-form .expanded .description .text {
-  -webkit-hyphens: auto;
-  -moz-hyphens: auto;
-  hyphens: auto;
-}
-.js #locale-translation-status-form .description .inner {
-  height: 20px;
-}
-#locale-translation-status-form .expanded .description .inner {
-  height: auto;
-  overflow: visible;
-  white-space: normal;
-}
-#locale-translation-status-form .details {
-  padding: 5px 0;
-  max-width: 490px;
-  white-space: normal;
-  font-size: 0.9em;
-  color: #666;
-}
-@media screen and (max-width: 40em) {
-  #locale-translation-status-form th.title {
-    width: 20%;
-  }
-  #locale-translation-status-form th.status {
-    width: 40%;
-  }
-}
diff --git a/core/modules/locale/locale.pages.inc b/core/modules/locale/locale.pages.inc
index a109f5f..7daf844 100644
--- a/core/modules/locale/locale.pages.inc
+++ b/core/modules/locale/locale.pages.inc
@@ -163,7 +163,8 @@ function locale_translate_filter_form($form, &$form_state) {
   $filter_values = locale_translate_filter_values();
 
   $form['#attached']['css'] = array(
-    drupal_get_path('module', 'locale') . '/locale.admin.css',
+    drupal_get_path('module', 'locale') . '/css/locale.admin.css',
+    drupal_get_path('module', 'locale') . '/css/locale.admin.skin.css',
   );
 
   $form['filters'] = array(
@@ -260,7 +261,8 @@ function locale_translate_edit_form($form, &$form_state) {
 
   $path = drupal_get_path('module', 'locale');
   $form['#attached']['css'] = array(
-    $path . '/locale.admin.css',
+    $path . '/css/locale.admin.css',
+    $path . '/css/locale.admin.skin.css',
   );
   $form['#attached']['library'][] = array('locale', 'drupal.locale.admin');
 
@@ -583,7 +585,8 @@ function locale_translation_status_form($form, &$form_state) {
   );
 
   $form['#attached']['library'][] = array('locale', 'drupal.locale.admin');
-  $form['#attached']['css'] = array(drupal_get_path('module', 'locale') . '/locale.admin.css');
+  $form['#attached']['css'] = array(drupal_get_path('module', 'locale') . '/css/locale.admin.css');
+  $form['#attached']['css'] = array(drupal_get_path('module', 'locale') . '/css/locale.admin.skin.css');
 
   $form['actions'] = array('#type' => 'actions');
   if ($languages_update) {
diff --git a/core/modules/menu/lib/Drupal/menu/MenuListController.php b/core/modules/menu/lib/Drupal/menu/MenuListController.php
index e557d92..e0c1a7d 100644
--- a/core/modules/menu/lib/Drupal/menu/MenuListController.php
+++ b/core/modules/menu/lib/Drupal/menu/MenuListController.php
@@ -71,7 +71,8 @@ public function getOperations(EntityInterface $entity) {
    */
   public function render() {
     $build = parent::render();
-    $build['#attached']['css'][] = drupal_get_path('module', 'menu') . '/menu.admin.css';
+    $build['#attached']['css'][] = drupal_get_path('module', 'menu') . '/css/menu.admin.css';
+    $build['#attached']['css'][] = drupal_get_path('module', 'menu') . '/css/menu.admin.skin.css';
     return $build;
   }
 
diff --git a/core/modules/menu/menu.admin.css b/core/modules/menu/menu.admin.css
deleted file mode 100644
index efbfe75..0000000
--- a/core/modules/menu/menu.admin.css
+++ /dev/null
@@ -1,6 +0,0 @@
-.menu-enabled {
-  width: 70px;
-}
-.menu-label {
-  font-weight: bold;
-}
diff --git a/core/modules/menu/menu.admin.inc b/core/modules/menu/menu.admin.inc
index 8869465..d3fa66e 100644
--- a/core/modules/menu/menu.admin.inc
+++ b/core/modules/menu/menu.admin.inc
@@ -71,7 +71,8 @@ function menu_overview_form($form, &$form_state) {
   $form['#theme'] = 'menu_overview_form';
   $form_state += array('menu_overview_form_parents' => array());
 
-  $form['#attached']['css'] = array(drupal_get_path('module', 'menu') . '/menu.admin.css');
+  $form['#attached']['css'] = array(drupal_get_path('module', 'menu') . '/css/menu.admin.css');
+  $form['#attached']['css'] = array(drupal_get_path('module', 'menu') . '/css/menu.admin.skin.css');
 
   $links = array();
   $query = Drupal::entityQuery('menu_link')
diff --git a/core/modules/translation_entity/translation_entity.admin.css b/core/modules/translation_entity/translation_entity.admin.css
deleted file mode 100644
index cab64f8..0000000
--- a/core/modules/translation_entity/translation_entity.admin.css
+++ /dev/null
@@ -1,35 +0,0 @@
-/**
- * @file
- * Styles for the content language administration page.
- */
-
-#language-content-settings-form table .bundle {
-  width: 24%;
-}
-
-#language-content-settings-form table td.bundle {
-  font-weight: bold;
-}
-
-#language-content-settings-form table .field,
-#language-content-settings-form table .column {
-  width: 24%;
-  padding-left: 3em;
-}
-
-#language-content-settings-form table .column {
-  padding-left: 5em;
-}
-
-#language-content-settings-form table .field label,
-#language-content-settings-form table .column label {
-  font-weight: normal;
-}
-
-#language-content-settings-form table .translatable {
-  width: 1%;
-}
-
-#language-content-settings-form table .operations {
-  width: 75%;
-}
diff --git a/core/modules/translation_entity/translation_entity.module b/core/modules/translation_entity/translation_entity.module
index e4dca3e..1bbfcda 100644
--- a/core/modules/translation_entity/translation_entity.module
+++ b/core/modules/translation_entity/translation_entity.module
@@ -362,7 +362,8 @@ function translation_entity_library_info() {
       $path . '/translation_entity.admin.js' => array(),
     ),
     'css' => array(
-      $path . '/translation_entity.admin.css' => array(),
+      $path . '/css/translation_entity.admin.css' => array(),
+      $path . '/css/translation_entity.admin.skin.css' => array(),
     ),
     'dependencies' => array(
       array('system', 'jquery'),
diff --git a/core/modules/update/update-rtl.css b/core/modules/update/update-rtl.css
deleted file mode 100644
index f181c84..0000000
--- a/core/modules/update/update-rtl.css
+++ /dev/null
@@ -1,35 +0,0 @@
-/**
- * @file
- * RTL styles used by the Update Manager module.
- */
-
-.update .project {
-  padding-right: .25em;
-}
-
-.update .version-status {
-  float: left;
-  padding-left: 10px;
-}
-
-.update .version-status .icon {
-  padding-right: .5em;
-}
-
-.update table.version .version-title {
-  padding-left: 1em;
-}
-
-.update table.version .version-details {
-  padding-left: .5em;
-  direction: ltr;
-}
-
-.update table.version .version-links {
-  text-align: left;
-  padding-left: 1em;
-}
-
-.update .check-manually {
-  padding-right: 1em;
-}
diff --git a/core/modules/update/update.css b/core/modules/update/update.css
deleted file mode 100644
index cb20500..0000000
--- a/core/modules/update/update.css
+++ /dev/null
@@ -1,135 +0,0 @@
-/**
- * @file
- * Styles used by the Update Manager module.
- */
-
-.update .project {
-  font-weight: bold;
-  font-size: 110%;
-  padding-left: .25em; /* LTR */
-  height: 22px;
-}
-
-.update .version-status {
-  float: right; /* LTR */
-  padding-right: 10px; /* LTR */
-  font-size: 110%;
-  height: 20px;
-}
-
-.update .version-status .icon {
-  padding-left: .5em; /* LTR */
-}
-
-.update .version-date {
-  white-space: nowrap;
-}
-
-.update .info {
-  margin: 0;
-  padding: 1em 1em .25em 1em;
-}
-
-.update tr.even,
-.update tr.odd {
-  border: none;
-}
-
-.update tr td {
-  border-top: 1px solid #ccc;
-  border-bottom: 1px solid #ccc;
-}
-
-.update tr.error {
-  background: #fcc;
-}
-
-.update tr.error .version-recommended {
-  background: #fdd;
-}
-
-.update tr.ok {
-  background: #dfd;
-}
-
-.update tr.warning {
-  background: #ffd;
-}
-
-.update tr.warning .version-recommended {
-  background: #ffe;
-}
-
-.current-version,
-.new-version {
-  direction: ltr; /* Note: version numbers should always be LTR. */
-}
-
-.update tr.unknown {
-  background: #ddd;
-}
-
-table.update,
-.update table.version {
-  width: 100%;
-  margin-top: .5em;
-  border: none;
-}
-
-.update table.version tbody {
-  border: none;
-}
-
-.update table.version tr,
-.update table.version td {
-  line-height: .9em;
-  padding: 0;
-  margin: 0;
-  border: none;
-  background: none;
-}
-
-.update table.version .version-title {
-  padding-left: 1em; /* LTR */
-  width: 14em;
-}
-
-.update table.version .version-details {
-  padding-right: .5em; /* LTR */
-}
-
-.update table.version .version-links {
-  text-align: right; /* LTR */
-  padding-right: 1em; /* LTR */
-}
-
-.update table.version-security .version-title {
-  color: #970f00;
-}
-
-.update table.version-recommended-strong .version-title {
-  font-weight: bold;
-}
-
-.update .security-error {
-  font-weight: bold;
-  color: #970f00;
-}
-
-.update .check-manually {
-  padding-left: 1em; /* LTR */
-}
-
-.update-major-version-warning {
-  color: #ff0000;
-}
-
-table tbody tr.update-security,
-table tbody tr.update-unsupported {
-  background: #fcc;
-}
-
-th.update-project-name {
-  width: 50%;
-}
-
diff --git a/core/modules/update/update.manager.inc b/core/modules/update/update.manager.inc
index bc84058..ccb90a7 100644
--- a/core/modules/update/update.manager.inc
+++ b/core/modules/update/update.manager.inc
@@ -77,7 +77,8 @@ function update_manager_update_form($form, $form_state = array(), $context) {
     return $form;
   }
 
-  $form['#attached']['css'][] = drupal_get_path('module', 'update') . '/update.css';
+  $form['#attached']['css'][] = drupal_get_path('module', 'update') . '/css/update.admin.css';
+  $form['#attached']['css'][] = drupal_get_path('module', 'update') . '/css/update.admin.skin.css';
 
   // This will be a nested array. The first key is the kind of project, which
   // can be either 'enabled', 'disabled', 'manual' (projects which require
diff --git a/core/modules/update/update.report.inc b/core/modules/update/update.report.inc
index 607b523..9f55611 100644
--- a/core/modules/update/update.report.inc
+++ b/core/modules/update/update.report.inc
@@ -247,7 +247,8 @@ function theme_update_report($variables) {
       $output .= theme('table', array('header' => $header, 'rows' => $rows[$type_name], 'attributes' => array('class' => array('update'))));
     }
   }
-  drupal_add_css(drupal_get_path('module', 'update') . '/update.css');
+  drupal_add_css(drupal_get_path('module', 'update') . '/css/update.admin.css');
+  drupal_add_css(drupal_get_path('module', 'update') . '/css/update.admin.skin.css');
   return $output;
 }
 
