diff --git a/core/includes/theme.maintenance.inc b/core/includes/theme.maintenance.inc
index fcd8703..d663d14 100644
--- a/core/includes/theme.maintenance.inc
+++ b/core/includes/theme.maintenance.inc
@@ -78,8 +78,6 @@ function _drupal_maintenance_theme() {
   $path = drupal_get_path('module', 'system');
   drupal_add_css($path . '/system.base.css');
   drupal_add_css($path . '/system.admin.css');
-  drupal_add_css($path . '/system.menus.css');
-  drupal_add_css($path . '/system.messages.css');
   drupal_add_css($path . '/system.theme.css');
   drupal_add_css($path . '/system.maintenance.css');
 }
diff --git a/core/modules/simpletest/tests/common.test b/core/modules/simpletest/tests/common.test
index 7a68f44..360c9db 100644
--- a/core/modules/simpletest/tests/common.test
+++ b/core/modules/simpletest/tests/common.test
@@ -723,13 +723,11 @@ class CascadingStylesheetsTestCase extends DrupalWebTestCase {
     drupal_add_css(drupal_get_path('module', 'simpletest') . '/simpletest.css');
     // A few system CSS files, ordered in a strange way.
     $system_path = drupal_get_path('module', 'system');
-    drupal_add_css($system_path . '/system.menus.css', array('group' => CSS_SYSTEM));
     drupal_add_css($system_path . '/system.base.css', array('group' => CSS_SYSTEM, 'weight' => -10));
     drupal_add_css($system_path . '/system.theme.css', array('group' => CSS_SYSTEM));
 
     $expected = array(
       $system_path . '/system.base.css',
-      $system_path . '/system.menus.css',
       $system_path . '/system.theme.css',
       drupal_get_path('module', 'simpletest') . '/simpletest.css',
     );
diff --git a/core/modules/system/system.menus-rtl.css b/core/modules/system/system.menus-rtl.css
deleted file mode 100644
index be85245..0000000
--- a/core/modules/system/system.menus-rtl.css
+++ /dev/null
@@ -1,37 +0,0 @@
-
-/**
- * @file
- * RTL styles for menus and navigation markup.
- */
-
-ul.menu {
-  text-align:right;
-}
-ul.menu li {
-  margin: 0 0.5em 0 0;
-}
-ul li.collapsed {
-  list-style-image: url(../../misc/menu-collapsed-rtl.png);
-}
-li.expanded,
-li.collapsed,
-li.leaf {
-  padding: 0.2em 0 0 0.5em;
-}
-
-/**
- * Markup generated by theme_menu_local_tasks().
- */
-ul.primary {
-  padding: 0 1em 0 0;
-}
-ul.primary li a {
-  margin-right: 5px;
-  margin-left: 0.5em;
-}
-ul.secondary li {
-  border-left: 1px solid #ccc;
-  border-right: none;
-  display: inline;
-  padding: 0 1em;
-}
diff --git a/core/modules/system/system.menus.css b/core/modules/system/system.menus.css
deleted file mode 100644
index 514b029..0000000
--- a/core/modules/system/system.menus.css
+++ /dev/null
@@ -1,116 +0,0 @@
-
-/**
- * @file
- * Styles for menus and navigation markup.
- */
-
-/**
- * Markup generated by theme_menu_tree().
- */
-ul.menu {
-  border: none;
-  list-style: none;
-  text-align: left; /* LTR */
-}
-ul.menu li {
-  margin: 0 0 0 0.5em; /* LTR */
-}
-ul li.expanded {
-  list-style-image: url(../../misc/menu-expanded.png);
-  list-style-type: circle;
-}
-ul li.collapsed {
-  list-style-image: url(../../misc/menu-collapsed.png); /* LTR */
-  list-style-type: disc;
-}
-ul li.leaf {
-  list-style-image: url(../../misc/menu-leaf.png);
-  list-style-type: square;
-}
-li.expanded,
-li.collapsed,
-li.leaf {
-  padding: 0.2em 0.5em 0 0; /* LTR */
-  margin: 0;
-}
-li a.active {
-  color: #000;
-}
-td.menu-disabled {
-  background: #ccc;
-}
-
-/**
- * Markup generated by theme_links().
- */
-ul.inline,
-ul.links.inline {
-  display: inline;
-  padding-left: 0;
-}
-ul.inline li {
-  display: inline;
-  list-style-type: none;
-  padding: 0 0.5em;
-}
-
-/**
- * Markup generated by theme_breadcrumb().
- */
-.breadcrumb {
-  padding-bottom: 0.5em;
-}
-
-/**
- * Markup generated by theme_menu_local_tasks().
- */
-ul.primary {
-  border-bottom: 1px solid #bbb;
-  border-collapse: collapse;
-  height: auto;
-  line-height: normal;
-  list-style: none;
-  margin: 5px;
-  padding: 0 0 0 1em; /* LTR */
-  white-space: nowrap;
-}
-ul.primary li {
-  display: inline;
-}
-ul.primary li a {
-  background-color: #ddd;
-  border-color: #bbb;
-  border-style: solid solid none solid;
-  border-width: 1px;
-  height: auto;
-  margin-right: 0.5em; /* LTR */
-  padding: 0 1em;
-  text-decoration: none;
-}
-ul.primary li.active a {
-  background-color: #fff;
-  border: 1px solid #bbb;
-  border-bottom: 1px solid #fff;
-}
-ul.primary li a:hover {
-  background-color: #eee;
-  border-color: #ccc;
-  border-bottom-color: #eee;
-}
-ul.secondary {
-  border-bottom: 1px solid #bbb;
-  padding: 0.5em 1em;
-  margin: 5px;
-}
-ul.secondary li {
-  border-right: 1px solid #ccc; /* LTR */
-  display: inline;
-  padding: 0 1em;
-}
-ul.secondary a {
-  padding: 0;
-  text-decoration: none;
-}
-ul.secondary a.active {
-  border-bottom: 4px solid #999;
-}
diff --git a/core/modules/system/system.messages-rtl.css b/core/modules/system/system.messages-rtl.css
deleted file mode 100644
index 445417b..0000000
--- a/core/modules/system/system.messages-rtl.css
+++ /dev/null
@@ -1,13 +0,0 @@
-
-/**
- * @file
- * RTL Styles for system messages.
- */
-
-div.messages {
-  background-position: 99% 8px;
-  padding: 10px 50px 10px 10px;
-}
-div.messages ul {
-  margin: 0 1em 0 0;
-}
diff --git a/core/modules/system/system.messages.css b/core/modules/system/system.messages.css
deleted file mode 100644
index ffd4e8e..0000000
--- a/core/modules/system/system.messages.css
+++ /dev/null
@@ -1,63 +0,0 @@
-
-/**
- * @file
- * Styles for system messages.
- */
-
-div.messages {
-  background-position: 8px 8px; /* LTR */
-  background-repeat: no-repeat;
-  border: 1px solid;
-  margin: 6px 0;
-  padding: 10px 10px 10px 50px; /* LTR */
-}
-
-div.status {
-  background-image: url(../../misc/message-24-ok.png);
-  border-color: #be7;
-}
-div.status,
-.ok {
-  color: #234600;
-}
-div.status,
-table tr.ok {
-  background-color: #f8fff0;
-}
-
-div.warning {
-  background-image: url(../../misc/message-24-warning.png);
-  border-color: #ed5;
-}
-div.warning,
-.warning {
-  color: #840;
-}
-div.warning,
-table tr.warning {
-  background-color: #fffce5;
-}
-
-div.error {
-  background-image: url(../../misc/message-24-error.png);
-  border-color: #ed541d;
-}
-div.error,
-.error {
-  color: #8c2e0b;
-}
-div.error,
-table tr.error {
-  background-color: #fef5f1;
-}
-div.error p.error {
-  color: #333;
-}
-
-div.messages ul {
-  margin: 0 0 0 1em; /* LTR */
-  padding: 0;
-}
-div.messages ul li {
-  list-style-image: none;
-}
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index e2e16ae..f16a273 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -1881,8 +1881,6 @@ function system_init() {
   if (path_is_admin(current_path())) {
     drupal_add_css($path . '/system.admin.css', array('group' => CSS_SYSTEM));
   }
-  drupal_add_css($path . '/system.menus.css', array('group' => CSS_SYSTEM, 'every_page' => TRUE));
-  drupal_add_css($path . '/system.messages.css', array('group' => CSS_SYSTEM, 'every_page' => TRUE));
   drupal_add_css($path . '/system.theme.css', array('group' => CSS_SYSTEM, 'every_page' => TRUE));
 
   // Ignore slave database servers for this request.
diff --git a/core/modules/system/system.theme-rtl.css b/core/modules/system/system.theme-rtl.css
index 0cd7fa6..354f218 100644
--- a/core/modules/system/system.theme-rtl.css
+++ b/core/modules/system/system.theme-rtl.css
@@ -51,3 +51,50 @@ html.js fieldset.collapsed .fieldset-legend {
   background-position: 98% 50%;
 }
 
+/**
+ * RTL styles for menus and navigation markup.
+ */
+
+ul.menu {
+  text-align:right;
+}
+ul.menu li {
+  margin: 0 0.5em 0 0;
+}
+ul li.collapsed {
+  list-style-image: url(../../misc/menu-collapsed-rtl.png);
+}
+li.expanded,
+li.collapsed,
+li.leaf {
+  padding: 0.2em 0 0 0.5em;
+}
+
+/**
+ * Markup generated by theme_menu_local_tasks().
+ */
+ul.primary {
+  padding: 0 1em 0 0;
+}
+ul.primary li a {
+  margin-right: 5px;
+  margin-left: 0.5em;
+}
+ul.secondary li {
+  border-left: 1px solid #ccc;
+  border-right: none;
+  display: inline;
+  padding: 0 1em;
+}
+
+/**
+ * RTL Styles for system messages.
+ */
+
+div.messages {
+  background-position: 99% 8px;
+  padding: 10px 50px 10px 10px;
+}
+div.messages ul {
+  margin: 0 1em 0 0;
+}
diff --git a/core/modules/system/system.theme.css b/core/modules/system/system.theme.css
index f34a965..786d1f5 100644
--- a/core/modules/system/system.theme.css
+++ b/core/modules/system/system.theme.css
@@ -237,3 +237,175 @@ th.checkbox {
 .progress .filled {
   background: #0072b9 url(../../misc/progress.gif);
 }
+
+/**
+ * Markup generated by theme_menu_tree().
+ */
+ul.menu {
+  border: none;
+  list-style: none;
+  text-align: left; /* LTR */
+}
+ul.menu li {
+  margin: 0 0 0 0.5em; /* LTR */
+}
+ul li.expanded {
+  list-style-image: url(../../misc/menu-expanded.png);
+  list-style-type: circle;
+}
+ul li.collapsed {
+  list-style-image: url(../../misc/menu-collapsed.png); /* LTR */
+  list-style-type: disc;
+}
+ul li.leaf {
+  list-style-image: url(../../misc/menu-leaf.png);
+  list-style-type: square;
+}
+li.expanded,
+li.collapsed,
+li.leaf {
+  padding: 0.2em 0.5em 0 0; /* LTR */
+  margin: 0;
+}
+li a.active {
+  color: #000;
+}
+td.menu-disabled {
+  background: #ccc;
+}
+
+/**
+ * Markup generated by theme_links().
+ */
+ul.inline,
+ul.links.inline {
+  display: inline;
+  padding-left: 0;
+}
+ul.inline li {
+  display: inline;
+  list-style-type: none;
+  padding: 0 0.5em;
+}
+
+/**
+ * Markup generated by theme_breadcrumb().
+ */
+.breadcrumb {
+  padding-bottom: 0.5em;
+}
+
+/**
+ * Markup generated by theme_menu_local_tasks().
+ */
+ul.primary {
+  border-bottom: 1px solid #bbb;
+  border-collapse: collapse;
+  height: auto;
+  line-height: normal;
+  list-style: none;
+  margin: 5px;
+  padding: 0 0 0 1em; /* LTR */
+  white-space: nowrap;
+}
+ul.primary li {
+  display: inline;
+}
+ul.primary li a {
+  background-color: #ddd;
+  border-color: #bbb;
+  border-style: solid solid none solid;
+  border-width: 1px;
+  height: auto;
+  margin-right: 0.5em; /* LTR */
+  padding: 0 1em;
+  text-decoration: none;
+}
+ul.primary li.active a {
+  background-color: #fff;
+  border: 1px solid #bbb;
+  border-bottom: 1px solid #fff;
+}
+ul.primary li a:hover {
+  background-color: #eee;
+  border-color: #ccc;
+  border-bottom-color: #eee;
+}
+ul.secondary {
+  border-bottom: 1px solid #bbb;
+  padding: 0.5em 1em;
+  margin: 5px;
+}
+ul.secondary li {
+  border-right: 1px solid #ccc; /* LTR */
+  display: inline;
+  padding: 0 1em;
+}
+ul.secondary a {
+  padding: 0;
+  text-decoration: none;
+}
+ul.secondary a.active {
+  border-bottom: 4px solid #999;
+}
+
+/**
+ * Styles for system messages.
+ */
+div.messages {
+  background-position: 8px 8px; /* LTR */
+  background-repeat: no-repeat;
+  border: 1px solid;
+  margin: 6px 0;
+  padding: 10px 10px 10px 50px; /* LTR */
+}
+
+div.status {
+  background-image: url(../../misc/message-24-ok.png);
+  border-color: #be7;
+}
+div.status,
+.ok {
+  color: #234600;
+}
+div.status,
+table tr.ok {
+  background-color: #f8fff0;
+}
+
+div.warning {
+  background-image: url(../../misc/message-24-warning.png);
+  border-color: #ed5;
+}
+div.warning,
+.warning {
+  color: #840;
+}
+div.warning,
+table tr.warning {
+  background-color: #fffce5;
+}
+
+div.error {
+  background-image: url(../../misc/message-24-error.png);
+  border-color: #ed541d;
+}
+div.error,
+.error {
+  color: #8c2e0b;
+}
+div.error,
+table tr.error {
+  background-color: #fef5f1;
+}
+div.error p.error {
+  color: #333;
+}
+
+div.messages ul {
+  margin: 0 0 0 1em; /* LTR */
+  padding: 0;
+}
+div.messages ul li {
+  list-style-image: none;
+}