diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index a07cae3..ed6c3c9 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -3092,7 +3092,6 @@ function template_process_maintenance_page(&$variables) {
   // selected should result in RTL stylesheets loaded properly already.
   $variables['css'] = $css = drupal_add_css();
   include_once DRUPAL_ROOT . '/core/modules/language/language.module';
-  language_css_alter($css);
   $variables['styles'] = drupal_get_css($css);
 
   $variables['scripts'] = drupal_get_js();
diff --git a/core/misc/dropbutton/dropbutton-rtl.css b/core/misc/dropbutton/dropbutton-rtl.css
deleted file mode 100644
index d677c84..0000000
--- a/core/misc/dropbutton/dropbutton-rtl.css
+++ /dev/null
@@ -1,21 +0,0 @@
-
-/**
- * @file
- * Base RTL styles for dropbuttons.
- */
-
-/**
- * The dropbutton arrow.
- */
-.dropbutton-toggle {
-  left: 0;
-  right: auto;
-}
-.dropbutton-arrow {
-  left: 0.6667em;
-  right: auto;
-}
-.js .dropbutton-multiple .dropbutton-widget {
-  padding-left: 2em;
-  padding-right: 0;
-}
diff --git a/core/misc/dropbutton/dropbutton.css b/core/misc/dropbutton/dropbutton.css
index 35e9692..98f6e5d 100644
--- a/core/misc/dropbutton/dropbutton.css
+++ b/core/misc/dropbutton/dropbutton.css
@@ -66,6 +66,10 @@
 .js .dropbutton-multiple .dropbutton-widget {
   padding-right: 2em; /* LTR */
 }
+.js[dir=rtl] .dropbutton-multiple .dropbutton-widget {
+  padding-left: 2em;
+  padding-right: 0;
+}
 .dropbutton-multiple.open,
 .dropbutton-multiple.open .dropbutton-widget {
   max-width: none;
@@ -89,6 +93,10 @@
   white-space: nowrap;
   width: 2em;
 }
+[dir=rtl] .dropbutton-toggle {
+  left: 0;
+  right: auto;
+}
 .dropbutton-toggle button {
   background: none;
   border: 0;
@@ -115,6 +123,10 @@
   width: 0;
   overflow: hidden;
 }
+[dir=rtl] .dropbutton-arrow {
+  left: 0.6667em;
+  right: auto;
+}
 .dropbutton-multiple.open .dropbutton-arrow {
   border-bottom: 0.3333em solid;
   border-top-color: transparent;
diff --git a/core/misc/dropbutton/dropbutton.theme-rtl.css b/core/misc/dropbutton/dropbutton.theme-rtl.css
deleted file mode 100644
index 3e0fd7f..0000000
--- a/core/misc/dropbutton/dropbutton.theme-rtl.css
+++ /dev/null
@@ -1,14 +0,0 @@
-
-/**
- * @file
- * General RTL styles for dropbuttons.
- */
-
-.dropbutton-multiple .dropbutton {
-  border-left: 1px solid #e8e8e8;
-  border-right: 0 none;
-}
-.dropbutton-multiple .dropbutton li > * {
-  margin-left: 0.25em;
-  margin-right: 0;
-}
diff --git a/core/misc/dropbutton/dropbutton.theme.css b/core/misc/dropbutton/dropbutton.theme.css
index c0a347f..757957a 100644
--- a/core/misc/dropbutton/dropbutton.theme.css
+++ b/core/misc/dropbutton/dropbutton.theme.css
@@ -21,6 +21,14 @@
 .dropbutton-multiple .dropbutton {
   border-right: 1px solid #e8e8e8; /* LTR */
 }
+[dir=rtl] .dropbutton-multiple .dropbutton {
+  border-left: 1px solid #e8e8e8;
+  border-right: 0 none;
+}
 .dropbutton-multiple .dropbutton .dropbutton-action > * {
   margin-right: 0.25em; /* LTR */
 }
+[dir=rtl] .dropbutton-multiple .dropbutton .dropbutton-action > * {
+  margin-left: 0.25em;
+  margin-right: 0;
+}
diff --git a/core/misc/print-rtl.css b/core/misc/print-rtl.css
deleted file mode 100644
index f99287a..0000000
--- a/core/misc/print-rtl.css
+++ /dev/null
@@ -1,7 +0,0 @@
-
-body {
-  direction: rtl;
-}
-th {
-  text-align: right;
-}
diff --git a/core/misc/print.css b/core/misc/print.css
index 0a56ef1..8ebc0cc 100644
--- a/core/misc/print.css
+++ b/core/misc/print.css
@@ -3,11 +3,17 @@ body {
   margin: 1em;
   background-color: #fff;
 }
+[dir=rtl] body {
+  direction: rtl;
+}
 th {
   text-align: left; /* LTR */
   color: #006;
   border-bottom: 1px solid #ccc;
 }
+[dir=rtl] th {
+  text-align: right;
+}
 tr.odd {
   background-color: #ddd;
 }
diff --git a/core/misc/vertical-tabs-rtl.css b/core/misc/vertical-tabs-rtl.css
deleted file mode 100644
index e83b958..0000000
--- a/core/misc/vertical-tabs-rtl.css
+++ /dev/null
@@ -1,14 +0,0 @@
-
-.vertical-tabs {
-  margin-left: 0;
-  margin-right: 15em;
-}
-.vertical-tabs-list {
-  float: right;
-  margin-left: 0;
-  margin-right: -15em;
-}
-.vertical-tab-button.selected {
-  border-left-width: 0;
-  border-right-width: 1px;
-}
diff --git a/core/misc/vertical-tabs.css b/core/misc/vertical-tabs.css
index 9ea579a..827c8f8 100644
--- a/core/misc/vertical-tabs.css
+++ b/core/misc/vertical-tabs.css
@@ -3,6 +3,10 @@
   margin: 1em 0 1em 15em; /* LTR */
   border: 1px solid #ccc;
 }
+[dir=rtl] .vertical-tabs {
+   margin-left: 0;
+   margin-right: 15em;
+}
 .vertical-tabs-list {
   float: left; /* LTR */
   width: 15em;
@@ -11,6 +15,11 @@
   border-top: 1px solid #ccc;
   list-style: none;
 }
+[dir=rtl] .vertical-tabs-list {
+  float: right;
+  margin-left: 0;
+  margin-right: -15em;
+}
 .vertical-tabs-pane {
   margin: 0;
   border: 0;
@@ -44,6 +53,10 @@
   border-right-width: 0; /* LTR */
   background-color: #fff;
 }
+[dir=rtl] .vertical-tab-button.selected {
+  border-left-width: 0;
+  border-right-width: 1px;
+}
 .vertical-tab-button.selected strong {
   color: #000;
 }
diff --git a/core/modules/book/css/book.theme-rtl.css b/core/modules/book/css/book.theme-rtl.css
deleted file mode 100644
index 381a4cc..0000000
--- a/core/modules/book/css/book.theme-rtl.css
+++ /dev/null
@@ -1,16 +0,0 @@
-/**
- * @file
- * Right-to-Left styling for the Book module.
- */
-
-/**
- * Book navigation.
- */
-.book-pager .previous {
-  float: right;
-  text-align: right;
-}
-.book-pager .next {
-  float: left;
-  text-align: left;
-}
diff --git a/core/modules/book/css/book.theme.css b/core/modules/book/css/book.theme.css
index f1da027..a63ee41 100644
--- a/core/modules/book/css/book.theme.css
+++ b/core/modules/book/css/book.theme.css
@@ -24,6 +24,10 @@
   text-align: left; /* LTR */
   width: 45%;
 }
+[dir=rtl] .book-pager .previous {
+  float: right;
+  text-align: right;
+}
 .book-pager .up {
   text-align: center;
   width: 8%;
@@ -33,3 +37,7 @@
   text-align: right; /* LTR */
   width: 45%;
 }
+[dir=rtl] .book-pager .next {
+  float: left;
+  text-align: left;
+}
diff --git a/core/modules/ckeditor/css/ckeditor.admin-rtl.css b/core/modules/ckeditor/css/ckeditor.admin-rtl.css
deleted file mode 100644
index 548a4f9..0000000
--- a/core/modules/ckeditor/css/ckeditor.admin-rtl.css
+++ /dev/null
@@ -1,33 +0,0 @@
-/**
- * @file
- * Styles for configuration of CKEditor module for right-to-left languages.
- */
-
-.ckeditor-toolbar-active > ul {
-  clear: right;
-  float: right;
-}
-
-ul.ckeditor-buttons li {
-  float: right;
-}
-
-ul.ckeditor-buttons li:first-child a {
-  border-top-right-radius: 2px;
-  border-bottom-right-radius: 2px;
-}
-ul.ckeditor-buttons li:last-child a {
-  border-top-left-radius: 2px;
-  border-bottom-left-radius: 2px;
-}
-ul.ckeditor-multiple-buttons {
-  float: right;
-}
-ul.ckeditor-multiple-buttons li {
-  float: right;
-}
-
-.ckeditor-row-controls {
-  float: left;
-  text-align: left;
-}
diff --git a/core/modules/ckeditor/css/ckeditor.admin.css b/core/modules/ckeditor/css/ckeditor.admin.css
index 272e3ea..432791c 100644
--- a/core/modules/ckeditor/css/ckeditor.admin.css
+++ b/core/modules/ckeditor/css/ckeditor.admin.css
@@ -24,6 +24,10 @@
   clear: left; /* LTR */
   float: left; /* LTR */
 }
+[dir=rtl] .ckeditor-toolbar-active > ul {
+  clear: right;
+  float: right;
+}
 #ckeditor-button-description {
   margin-bottom: 1em;
 }
@@ -61,6 +65,9 @@ ul.ckeditor-buttons li {
   margin: 0;
   float: left; /* LTR */
 }
+[dir=rtl] ul.ckeditor-buttons li {
+  float: right;
+}
 ul.ckeditor-buttons li a {
   position: relative;
   display: block;
@@ -92,10 +99,18 @@ ul.ckeditor-buttons li:first-child a {
   border-top-left-radius: 2px; /* LTR */
   border-bottom-left-radius: 2px; /* LTR */
 }
+[dir=rtl] ul.ckeditor-buttons li:first-child a {
+  border-top-right-radius: 2px;
+  border-bottom-right-radius: 2px;
+}
 ul.ckeditor-buttons li:last-child a {
   border-top-right-radius: 2px; /* LTR */
   border-bottom-right-radius: 2px; /* LTR */
 }
+[dir=rtl] ul.ckeditor-buttons li:last-child a {
+  border-top-left-radius: 2px;
+  border-bottom-left-radius: 2px;
+}
 ul.ckeditor-buttons li.ckeditor-button-placeholder a {
   background: #333;
   opacity: 0.3;
@@ -106,12 +121,18 @@ ul.ckeditor-multiple-buttons {
   list-style: none;
   float: left; /* LTR */
 }
+[dir=rtl] ul.ckeditor-multiple-buttons {
+  float: right;
+}
 ul.ckeditor-multiple-buttons li {
   display: inline-block;
   float: left; /* LTR */
   margin: 0;
   padding: 0;
 }
+[dir=rtl] ul.ckeditor-multiple-buttons li {
+  float: right;
+}
 ul.ckeditor-multiple-buttons li a {
   cursor: move;
   display: inline-block;
@@ -176,6 +197,10 @@ ul.ckeditor-multiple-buttons li.ckeditor-button-separator a {
   width: 40px;
   text-align: right; /* LTR */
 }
+[dir=rtl] .ckeditor-row-controls {
+  float: left;
+  text-align: left;
+}
 .ckeditor-row-controls a {
   display: inline-block;
   padding: 6px 2px;
diff --git a/core/modules/color/css/color.admin-rtl.css b/core/modules/color/css/color.admin-rtl.css
deleted file mode 100644
index f8dbbd5..0000000
--- a/core/modules/color/css/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/css/color.admin.css b/core/modules/color/css/color.admin.css
index 98e9cc2..c3b471b 100644
--- a/core/modules/color/css/color.admin.css
+++ b/core/modules/color/css/color.admin.css
@@ -13,6 +13,10 @@
   top: 0;
   right: 0; /* LTR */
 }
+[dir=rtl] #placeholder {
+  left: 0;
+  right: auto;
+}
 
 /* Palette */
 .color-form .form-item {
@@ -21,21 +25,36 @@
   padding-left: 1em; /* LTR */
   margin: 0.5em 0;
 }
+[dir=rtl] .color-form .form-item {
+  padding-left: 0;
+  padding-right: 1em;
+}
 .color-form label {
   float: left; /* LTR */
   clear: left; /* LTR */
   width: 10em;
 }
+[dir=rtl] .color-form label {
+  float: right;
+  clear: right;
+}
 .color-form .form-text,
 .color-form .form-select {
   float: left; /* LTR */
 }
+[dir=rtl] .color-form .form-text,
+[dir=rtl] .color-form .form-select {
+  float: right;
+}
 .color-form .form-text {
   text-align: center;
   margin-right: 5px; /* LTR */
   cursor: pointer;
 }
-
+[dir=rtl] .color-form .form-text {
+  margin-right: 0;
+  margin-left: 5px;
+}
 #palette .hook {
   float: left; /* LTR */
   margin-top: 3px;
@@ -47,13 +66,23 @@
 #palette .both {
   background: url(../images/hook.png) no-repeat 100% 0; /* LTR */
 }
+[dir=rtl] #palette .down,
+[dir=rtl] #palette .up,
+[dir=rtl] #palette .both {
+  background: url(images/hook-rtl.png) no-repeat 0 0;
+}
 #palette .up {
   background-position: 100% -27px; /* LTR */
 }
+[dir=rtl] #palette .up {
+  background-position: 0 -27px;
+}
 #palette .both {
   background-position: 100% -54px; /* LTR */
 }
-
+[dir=rtl] #palette .both {
+  background-position: 0 -54px;
+}
 #palette .lock {
   float: left; /* LTR */
   position: relative;
@@ -64,6 +93,10 @@
   background: url(../images/lock.png) no-repeat 50% 2px;
   cursor: pointer;
 }
+[dir=rtl] #palette .lock {
+  float: right;
+  right: -10px;
+}
 #palette .unlocked {
   background-position: 50% -22px;
 }
@@ -83,3 +116,6 @@
   position: relative;
   float: left; /* LTR */
 }
+.js[dir=rtl] #preview {
+  float: right;
+}
diff --git a/core/modules/comment/css/comment.theme-rtl.css b/core/modules/comment/css/comment.theme-rtl.css
deleted file mode 100644
index c121023..0000000
--- a/core/modules/comment/css/comment.theme-rtl.css
+++ /dev/null
@@ -1,13 +0,0 @@
-
-/**
- * @file
- * RTL styles for comment module.
- */
-
-/**
- * Indent threaded comments.
- */
-.indented {
-  margin-left: 0;
-  margin-right: 25px;
-}
diff --git a/core/modules/comment/css/comment.theme.css b/core/modules/comment/css/comment.theme.css
index 6a32a63..51fd293 100644
--- a/core/modules/comment/css/comment.theme.css
+++ b/core/modules/comment/css/comment.theme.css
@@ -10,3 +10,7 @@
 .indented {
   margin-left: 25px; /* LTR */
 }
+[dir=rtl] .indented {
+  margin-left: 0;
+  margin-right: 25px;
+}
diff --git a/core/modules/contextual/css/contextual.theme-rtl.css b/core/modules/contextual/css/contextual.theme-rtl.css
deleted file mode 100644
index c001e31..0000000
--- a/core/modules/contextual/css/contextual.theme-rtl.css
+++ /dev/null
@@ -1,32 +0,0 @@
-/**
- * @file
- * RTL styling for contextual module.
- */
-
-/**
- * Contextual links wrappers.
- */
-.contextual {
-  left: 0;
-  right: auto;
-}
-
-/**
- * Contextual trigger.
- */
-.contextual .trigger {
-  float: left;
-  right: auto;
-  left: 2px;
-}
-
-/**
- * Contextual links.
- */
-.contextual-region .contextual .contextual-links {
-  border-radius: 0 4px 4px 4px;
-  float: left;
-  left: 2px;
-  right: auto;
-  text-align: right;
-}
diff --git a/core/modules/contextual/css/contextual.theme.css b/core/modules/contextual/css/contextual.theme.css
index a371afa..1387744 100644
--- a/core/modules/contextual/css/contextual.theme.css
+++ b/core/modules/contextual/css/contextual.theme.css
@@ -12,6 +12,10 @@
   top: 2px;
   z-index: 500;
 }
+[dir=rtl] .contextual {
+  left: 0;
+  right: auto;
+}
 
 /**
  * Contextual region.
@@ -47,6 +51,11 @@
   text-indent: -9999px;
   cursor: pointer;
 }
+[dir=rtl] .contextual .trigger {
+  float: left;
+  right: auto;
+  left: 2px;
+}
 .contextual.open .trigger {
   border-bottom-color: transparent;
   border-radius: 13px 13px 0 0;
@@ -73,6 +82,13 @@
   top: -1px;
   white-space: nowrap;
 }
+[dir=rtl] .contextual-region .contextual .contextual-links {
+  border-radius: 0 4px 4px 4px;
+  float: left;
+  left: 2px;
+  right: auto;
+  text-align: right;
+}
 .contextual-region .contextual .contextual-links li {
   background-color: #fff;
   border: none;
diff --git a/core/modules/contextual/css/contextual.toolbar-rtl.css b/core/modules/contextual/css/contextual.toolbar-rtl.css
deleted file mode 100644
index 226969f..0000000
--- a/core/modules/contextual/css/contextual.toolbar-rtl.css
+++ /dev/null
@@ -1,11 +0,0 @@
-/**
- * @file
- * RTL styling for contextual module's toolbar tab.
- */
-
-.js .toolbar .bar .contextual-toolbar-tab.tab {
-  float: left;
-}
-.js .toolbar .bar .contextual-toolbar-tab button {
-  padding-right: 1.3333em;
-}
diff --git a/core/modules/contextual/css/contextual.toolbar.css b/core/modules/contextual/css/contextual.toolbar.css
index 72baa68..b4fcd1f 100644
--- a/core/modules/contextual/css/contextual.toolbar.css
+++ b/core/modules/contextual/css/contextual.toolbar.css
@@ -16,6 +16,9 @@
 .js .toolbar .bar .contextual-toolbar-tab.tab {
   float: right; /* LTR */
 }
+.js[dir=rtl] .toolbar .bar .contextual-toolbar-tab.tab {
+  float: left;
+}
 .js .toolbar .bar .contextual-toolbar-tab button {
   padding-bottom: 1em;
   padding-top: 1em;
@@ -24,6 +27,9 @@
   text-indent: -9999px;
   line-height: 1em;
 }
+.js[dir=rtl] .toolbar .bar .contextual-toolbar-tab button {
+  padding-right: 1.3333em;
+}
 .js .toolbar .bar .contextual-toolbar-tab button.active {
   background-image:-moz-linear-gradient(rgb(78,159,234) 0%,rgb(69,132,221) 100%);
   background-image:-webkit-gradient(linear,color-stop(0, rgb(78,159,234)),color-stop(1, rgb(69,132,221)));
diff --git a/core/modules/dblog/css/dblog.module-rtl.css b/core/modules/dblog/css/dblog.module-rtl.css
deleted file mode 100644
index 7326fa8..0000000
--- a/core/modules/dblog/css/dblog.module-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/css/dblog.module.css b/core/modules/dblog/css/dblog.module.css
index 5732388..66ce59a 100644
--- a/core/modules/dblog/css/dblog.module.css
+++ b/core/modules/dblog/css/dblog.module.css
@@ -2,13 +2,16 @@
  * @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%;
 }
+[dir=rtl] .dblog-filter-form .form-item-type,
+[dir=rtl] .dblog-filter-form .form-item-severity {
+  margin: .1em .1em .1em .9em;
+}
 .dblog-filter-form .form-actions {
   display: inline-block;
   padding: 3ex 0 0;
diff --git a/core/modules/entity_reference/css/entity_reference.admin-rtl.css b/core/modules/entity_reference/css/entity_reference.admin-rtl.css
deleted file mode 100644
index 3302ab8..0000000
--- a/core/modules/entity_reference/css/entity_reference.admin-rtl.css
+++ /dev/null
@@ -1,4 +0,0 @@
-
-.entity_reference-settings {
-  margin-right: 1.5em;
-}
diff --git a/core/modules/entity_reference/css/entity_reference.admin.css b/core/modules/entity_reference/css/entity_reference.admin.css
index d608ccf..8c6c382 100644
--- a/core/modules/entity_reference/css/entity_reference.admin.css
+++ b/core/modules/entity_reference/css/entity_reference.admin.css
@@ -2,3 +2,6 @@
 .entity_reference-settings {
   margin-left: 1.5em; /* LTR */
 }
+[dir=rtl] .entity_reference-settings {
+  margin-right: 1.5em;
+}
diff --git a/core/modules/field/css/field.module-rtl.css b/core/modules/field/css/field.module-rtl.css
deleted file mode 100644
index 4c2dec9..0000000
--- a/core/modules/field/css/field.module-rtl.css
+++ /dev/null
@@ -1,10 +0,0 @@
-form .field-multiple-table .field-multiple-drag {
-  padding-left: 0;
-}
-form .field-multiple-table .field-multiple-drag .tabledrag-handle{
-  padding-left: .5em;
-}
-.field-label-inline .field-label,
-.field-label-inline .field-items {
-  float: right;
-}
diff --git a/core/modules/field/css/field.module.css b/core/modules/field/css/field.module.css
index 2ec03af..aa8e9d3 100644
--- a/core/modules/field/css/field.module.css
+++ b/core/modules/field/css/field.module.css
@@ -7,6 +7,10 @@
 .field-label-inline .field-items {
   float:left; /*LTR*/
 }
+[dir=rtl] .field-label-inline .field-label,
+[dir=rtl] .field-label-inline .field-items {
+  float: right;
+}
 
 /* Form display */
 form .field-edit-link {
@@ -19,10 +23,15 @@ form .field-multiple-table .field-multiple-drag {
   width: 30px;
   padding-right: 0; /*LTR*/
 }
+[dir=rtl] form .field-multiple-table .field-multiple-drag {
+  padding-left: 0;
+}
 form .field-multiple-table .field-multiple-drag .tabledrag-handle {
   padding-right: .5em; /*LTR*/
 }
-
+[dir=rtl] form .field-multiple-table .field-multiple-drag .tabledrag-handle{
+  padding-left: .5em;
+}
 form .field-add-more-submit {
   margin: .5em 0 0;
 }
diff --git a/core/modules/field_ui/css/field_ui.admin-rtl.css b/core/modules/field_ui/css/field_ui.admin-rtl.css
deleted file mode 100644
index 3b50ab3..0000000
--- a/core/modules/field_ui/css/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/css/field_ui.admin.css b/core/modules/field_ui/css/field_ui.admin.css
index cf59695..d58e46e 100644
--- a/core/modules/field_ui/css/field_ui.admin.css
+++ b/core/modules/field_ui/css/field_ui.admin.css
@@ -7,6 +7,9 @@
 .field-ui-overview .add-new .label-input {
   float: left; /* LTR */
 }
+[dir=rtl] .field-ui-overview .add-new .label-input {
+  float: right;
+}
 .field-ui-overview .add-new .tabledrag-changed {
   display: none;
 }
diff --git a/core/modules/filter/css/filter.admin-rtl.css b/core/modules/filter/css/filter.admin-rtl.css
deleted file mode 100644
index 4d972e2..0000000
--- a/core/modules/filter/css/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/css/filter.admin.css b/core/modules/filter/css/filter.admin.css
index ac21686..09ed0e0 100644
--- a/core/modules/filter/css/filter.admin.css
+++ b/core/modules/filter/css/filter.admin.css
@@ -27,6 +27,9 @@
 .filter-help {
   float: right; /* LTR */
 }
+[dir=rtl] .filter-help {
+  float: left;
+}
 .filter-help p {
   margin: 0;
 }
@@ -34,6 +37,10 @@
   background: transparent url(../../../misc/help.png) right center no-repeat; /* LTR */
   padding: 0 20px 0 0; /* LTR */
 }
+[dir=rtl] .filter-help a {
+  background-position: left center;
+  padding: 0 0 0 20px;
+}
 
 .text-format-wrapper .description {
   margin-top: 0.5em;
@@ -52,3 +59,6 @@
 .tips {
   padding-left: 0; /* LTR */
 }
+[dir=rtl] .tips {
+  padding-right: 0;
+}
diff --git a/core/modules/forum/css/forum.module-rtl.css b/core/modules/forum/css/forum.module-rtl.css
deleted file mode 100644
index 0e5d3ed..0000000
--- a/core/modules/forum/css/forum.module-rtl.css
+++ /dev/null
@@ -1,24 +0,0 @@
-/**
- * @file
- * Right-to-left styling for the Forum module.
- */
-
-#forum .icon {
-  float: right;
-  margin: 0 0 0 9px;
-}
-#forum div.indent {
-  margin-left: 0;
-  margin-right: 20px;
-}
-.forum-topic-navigation {
-  padding: 1em 3em 0 0;
-}
-.forum-topic-navigation .topic-previous {
-  text-align: left;
-  float: right;
-}
-.forum-topic-navigation .topic-next {
-  text-align: right;
-  float: left;
-}
diff --git a/core/modules/forum/css/forum.module.css b/core/modules/forum/css/forum.module.css
index 0c4f8fc..3afc98a 100644
--- a/core/modules/forum/css/forum.module.css
+++ b/core/modules/forum/css/forum.module.css
@@ -23,12 +23,20 @@
   margin: 0 9px 0 0; /* LTR */
   width: 24px;
 }
+[dir=rtl] #forum .icon {
+  float: right;
+  margin: 0 0 0 9px;
+}
 #forum .title {
   overflow: hidden;
 }
 #forum div.indent {
   margin-left: 20px; /* LTR */
 }
+[dir=rtl] #forum div.indent {
+  margin-left: 0;
+  margin-right: 20px;
+}
 
 #forum .topic-status-new {
   background-position: -24px 0;
@@ -45,3 +53,15 @@
 #forum .topic-status-closed {
   background-position: -120px 0;
 }
+
+[dir=rtl] .forum-topic-navigation {
+  padding: 1em 3em 0 0;
+}
+[dir=rtl] .forum-topic-navigation .topic-previous {
+  text-align: left;
+  float: right;
+}
+[dir=rtl] .forum-topic-navigation .topic-next {
+  text-align: right;
+  float: left;
+}
diff --git a/core/modules/help/css/help.module-rtl.css b/core/modules/help/css/help.module-rtl.css
deleted file mode 100644
index 035d5d2..0000000
--- a/core/modules/help/css/help.module-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/css/help.module.css b/core/modules/help/css/help.module.css
index 5d074c8..e65e1cd 100644
--- a/core/modules/help/css/help.module.css
+++ b/core/modules/help/css/help.module.css
@@ -4,9 +4,19 @@
   width: 22%;
   margin-right: 3%; /* LTR */
 }
+[dir=rtl] .help-items {
+  float: right;
+  margin-right: 0;
+  margin-left: 3%;
+}
 .help-items-last {
   margin-right: 0; /* LTR */
 }
+[dir=rtl] .help-items-last {
+  margin-right: 0;
+  margin-left: 0;
+}
+
 
 /**
  * Avoid text overlapping on a narrow viewport.
diff --git a/core/modules/image/css/image.theme-rtl.css b/core/modules/image/css/image.theme-rtl.css
deleted file mode 100644
index facb97b..0000000
--- a/core/modules/image/css/image.theme-rtl.css
+++ /dev/null
@@ -1,11 +0,0 @@
-
-/**
- * Image upload widget.
- */
-.image-preview {
-  float: right;
-  padding: 0 0 10px 10px;
-}
-.image-widget-data {
-  float: right;
-}
diff --git a/core/modules/image/css/image.theme.css b/core/modules/image/css/image.theme.css
index 9f7d534..4a3045d 100644
--- a/core/modules/image/css/image.theme.css
+++ b/core/modules/image/css/image.theme.css
@@ -6,9 +6,16 @@
   float: left; /* LTR */
   padding: 0 10px 10px 0; /* LTR */
 }
+[dir=rtl] .image-preview {
+  float: right;
+  padding: 0 0 10px 10px;
+}
 .image-widget-data {
   float: left; /* LTR */
 }
+[dir=rtl] .image-widget-data {
+  float: right;
+}
 .image-widget-data .text-field {
   width: auto;
 }
diff --git a/core/modules/language/language.module b/core/modules/language/language.module
index 6b45fa1..04809f4 100644
--- a/core/modules/language/language.module
+++ b/core/modules/language/language.module
@@ -562,33 +562,6 @@ function language_delete($langcode) {
 }
 
 /**
- * Implements hook_css_alter().
- *
- * This function checks all CSS files currently added via drupal_add_css() and
- * and checks to see if a related right to left CSS file should be included.
- */
-function language_css_alter(&$css) {
-  $language_interface = language(Language::TYPE_INTERFACE);
-
-  // If the current language is RTL, add the CSS file with the RTL overrides.
-  if ($language_interface->direction == Language::DIRECTION_RTL) {
-    foreach ($css as $data => $item) {
-      // Only provide RTL overrides for files.
-      if ($item['type'] == 'file') {
-        $rtl_path = str_replace('.css', '-rtl.css', $item['data']);
-        if (file_exists($rtl_path) && !isset($css[$rtl_path])) {
-          // Replicate the same item, but with the RTL path and a little larger
-          // weight so that it appears directly after the original CSS file.
-          $item['data'] = $rtl_path;
-          $item['weight'] += 0.01;
-          $css[$rtl_path] = $item;
-        }
-      }
-    }
-  }
-}
-
-/**
  * Implements hook_language_types_info().
  *
  * Defines the three core language types:
diff --git a/core/modules/layout/layouts/static/twocol/two-col-rtl.css b/core/modules/layout/layouts/static/twocol/two-col-rtl.css
deleted file mode 100644
index 0fe6a0a..0000000
--- a/core/modules/layout/layouts/static/twocol/two-col-rtl.css
+++ /dev/null
@@ -1,6 +0,0 @@
-/* Large resolutions (desktop, tablets in landscape, ...) */
-@media only screen and (min-width: 59em) {
-  .layout-two-col .layout-region {
-    float: right;
-  }
-}
diff --git a/core/modules/layout/layouts/static/twocol/two-col.css b/core/modules/layout/layouts/static/twocol/two-col.css
index bb7ae25..dfe92b3 100644
--- a/core/modules/layout/layouts/static/twocol/two-col.css
+++ b/core/modules/layout/layouts/static/twocol/two-col.css
@@ -4,4 +4,7 @@
     float: left; /* LTR */
     width: 50%;
   }
+  [dir=rtl] .layout-two-col .layout-region {
+    float: right;
+  }
 }
diff --git a/core/modules/locale/css/locale.admin-rtl.css b/core/modules/locale/css/locale.admin-rtl.css
deleted file mode 100644
index 0b78f1b..0000000
--- a/core/modules/locale/css/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/css/locale.admin.css b/core/modules/locale/css/locale.admin.css
index d7bd328..8bc260d 100644
--- a/core/modules/locale/css/locale.admin.css
+++ b/core/modules/locale/css/locale.admin.css
@@ -14,6 +14,13 @@
    */
   width: 15em;
 }
+[dir=rtl] .locale-translate-filter-form .form-item-langcode,
+[dir=rtl] .locale-translate-filter-form .form-item-translation,
+[dir=rtl] .locale-translate-filter-form .form-item-customized {
+  float: right;
+  margin-left: 1em;
+  margin-right: 0;
+}
 .locale-translate-filter-form .form-type-select select {
   width: 100%;
 }
@@ -21,6 +28,10 @@
   float: left; /* LTR */
   padding: 3.8ex 0 0 0; /* LTR */
 }
+[dir=rtl] .locale-translate-filter-form .form-actions {
+  float: right;
+  padding: 3.5ex 0 0 0;
+}
 .locale-translate-edit-form th {
   width: 50%;
   table-layout: fixed;
diff --git a/core/modules/overlay/css/overlay-child-rtl.css b/core/modules/overlay/css/overlay-child-rtl.css
deleted file mode 100644
index 0751b56..0000000
--- a/core/modules/overlay/css/overlay-child-rtl.css
+++ /dev/null
@@ -1,29 +0,0 @@
-/**
- * @file
- * RTL styling for Overlay child pages.
- */
-
-html {
-  direction: rtl;
-}
-
-#overlay-title {
-  float: right;
-  left: auto;
-}
-#overlay-close-wrapper {
-  left: 0;
-  right: auto;
-}
-#overlay-close,
-#overlay-close:hover {
-  border-radius: 12px 0 0 12px;
-}
-
-/**
- * Tabs on the overlay.
- */
-#overlay-tabs {
-  left: 20px;
-  right: auto;
-}
diff --git a/core/modules/overlay/css/overlay-child.css b/core/modules/overlay/css/overlay-child.css
index 4610749..6fe068d 100644
--- a/core/modules/overlay/css/overlay-child.css
+++ b/core/modules/overlay/css/overlay-child.css
@@ -3,6 +3,10 @@
  * Basic styling for the Overlay child pages.
  */
 
+html[dir=rtl] {
+  direction: rtl;
+}
+
 .js {
   background: transparent !important;
   overflow-y: scroll;
@@ -49,6 +53,10 @@
   margin: 0;
   padding: 0.3em 0;
 }
+[dir=rtl] #overlay-title {
+  float: right;
+  left: auto;
+}
 #overlay-title:active,
 #overlay-title:focus {
   outline: 0;
@@ -61,6 +69,10 @@
   position: absolute;
   right: 0; /* LTR */
 }
+[dir=rtl] #overlay-close-wrapper {
+  left: 0;
+  right: auto;
+}
 #overlay-close,
 #overlay-close:hover {
   background: #ffffff url(../images/close.png) no-repeat;
@@ -73,6 +85,10 @@
   position: absolute;
   width: 26px;
 }
+[dir=rtl] #overlay-close,
+[dir=rtl] #overlay-close:hover {
+  border-radius: 12px 0 0 12px;
+}
 
 /**
  * Tabs on the overlay.
@@ -84,6 +100,10 @@
   right: 20px; /* LTR */
   text-transform: uppercase;
 }
+[dir=rtl] #overlay-tabs {
+  left: 20px;
+  right: auto;
+}
 #overlay-tabs li {
   display: inline-block;
   list-style: none;
diff --git a/core/modules/shortcut/css/shortcut.module-rtl.css b/core/modules/shortcut/css/shortcut.module-rtl.css
deleted file mode 100644
index ed903a7..0000000
--- a/core/modules/shortcut/css/shortcut.module-rtl.css
+++ /dev/null
@@ -1,13 +0,0 @@
-
-/**
- * @file
- * Generic RTL base styles for shortcut module.
- */
-
-/**
- * Add/remove links.
- */
-.add-or-remove-shortcuts .icon,
-.add-or-remove-shortcuts .text {
-  float: right;
-}
diff --git a/core/modules/shortcut/css/shortcut.module.css b/core/modules/shortcut/css/shortcut.module.css
index 8575904..4d1f641 100644
--- a/core/modules/shortcut/css/shortcut.module.css
+++ b/core/modules/shortcut/css/shortcut.module.css
@@ -16,6 +16,10 @@
   float: left; /* LTR */
   padding-top: 2px;
 }
+[dir=rtl] .add-or-remove-shortcuts .icon,
+[dir=rtl] .add-or-remove-shortcuts .text {
+  float: right;
+}
 .add-or-remove-shortcuts a:focus .text,
 .add-or-remove-shortcuts a:hover .text {
   display: block;
diff --git a/core/modules/shortcut/css/shortcut.theme-rtl.css b/core/modules/shortcut/css/shortcut.theme-rtl.css
deleted file mode 100644
index 8a687d9..0000000
--- a/core/modules/shortcut/css/shortcut.theme-rtl.css
+++ /dev/null
@@ -1,41 +0,0 @@
-
-/**
- * @file
- * RTL styling for the shortcut module.
- */
-
-/**
- * Add/remove links.
- */
-.add-or-remove-shortcuts .icon {
-  margin-left: 0;
-  margin-right: 8px;
-}
-.add-shortcut a:focus .icon,
-.add-shortcut a:hover .icon {
-  background-position: 0 -24px;
-}
-.remove-shortcut a:focus .icon,
-.remove-shortcut a:hover .icon {
-  background-position: -12px -24px;
-}
-.add-or-remove-shortcuts .text {
-  padding: 0 10px 0 6px;
-}
-.add-or-remove-shortcuts a:focus .text,
-.add-or-remove-shortcuts a:hover .text {
-  border-radius: 5px 0 0 5px;
-}
-
-/**
- * Toolbar.
- */
-.toolbar-js .horizontal #edit-shortcuts {
-  border-left: 0 none;
-  border-right: 1px solid #d9d9d9;
-  float: right;
-  margin-left: 0;
-  margin-right: 0.3333em;
-  padding-left: 0.3333em;
-  padding-right: 0.6667em;
-}
diff --git a/core/modules/shortcut/css/shortcut.theme.css b/core/modules/shortcut/css/shortcut.theme.css
index a9525a7..df5a6e8 100644
--- a/core/modules/shortcut/css/shortcut.theme.css
+++ b/core/modules/shortcut/css/shortcut.theme.css
@@ -26,6 +26,15 @@
 .toolbar .horizontal .edit-shortcuts {
   float: left; /* LTR */
 }
+[dir=rtl] .toolbar .horizontal .edit-shortcuts {
+  border-left: 0 none;
+  border-right: 1px solid #d9d9d9;
+  float: right;
+  margin-left: 0;
+  margin-right: 0.3333em;
+  padding-left: 0.3333em;
+  padding-right: 0.6667em;
+}
 
 /**
  * Add/remove links.
@@ -38,10 +47,25 @@
   text-indent: 12px;
   width: 12px;
 }
+[dir=rtl] .add-or-remove-shortcuts .icon {
+  margin-left: 0;
+  margin-right: 8px;
+}
+[dir=rtl] .add-or-remove-shortcuts .text {
+  padding: 0 10px 0 6px;
+}
+[dir=rtl] .add-or-remove-shortcuts a:focus .text,
+[dir=rtl] .add-or-remove-shortcuts a:hover .text {
+  border-radius: 5px 0 0 5px;
+}
 .add-shortcut a:focus .icon,
 .add-shortcut a:hover .icon {
   background-position: 0 -12px; /* LTR */
 }
+[dir=rtl] .add-shortcut a:focus .icon,
+[dir=rtl] .add-shortcut a:hover .icon {
+  background-position: 0 -24px;
+}
 .remove-shortcut .icon {
   margin-top: 4px;
   background-position: -12px 0;
@@ -50,3 +74,7 @@
 .remove-shortcut a:hover .icon {
   background-position: -12px -12px; /* LTR */
 }
+[dir=rtl] .remove-shortcut a:focus .icon,
+[dir=rtl] .remove-shortcut a:hover .icon {
+  background-position: -12px -24px;
+}
diff --git a/core/modules/system/css/system.admin-rtl.css b/core/modules/system/css/system.admin-rtl.css
deleted file mode 100644
index 04ec9fc..0000000
--- a/core/modules/system/css/system.admin-rtl.css
+++ /dev/null
@@ -1,101 +0,0 @@
-/**
- * @file
- * RTL styles for administration pages.
- */
-
-/**
- * Administration blocks.
- */
-div.admin-panel .body {
-  padding: 0 8px 2px 4px;
-}
-@media screen and (min-width: 40em) {
-  div.admin .left {
-    float: right;
-    margin-left: 0;
-    margin-right: 1em;
-  }
-  div.admin .right {
-    float: left;
-    margin-left: 1em;
-    margin-right: 0;
-  }
-}
-div.admin .expert-link {
-  margin-right: 0;
-  margin-left: 1em;
-  padding-right: 0;
-  padding-left: 4px;
-  text-align: left;
-}
-
-/**
- * Status report.
- */
-table.system-status-report td.status-icon {
-  padding-left: 0;
-  padding-right: 6px;
-}
-
-/**
- * Appearance page.
- */
-/**
-* Theme display without vertical toolbar.
-*/
-@media screen and (min-width: 45em) {
-  body:not(.toolbar-vertical) .system-themes-list-enabled .screenshot,
-  body:not(.toolbar-vertical) .system-themes-list-enabled .no-screenshot {
-    float: right;
-    margin: 0 0 0 20px;
-  }
-  body:not(.toolbar-vertical) .system-themes-list-disabled .theme-selector {
-    float: right;
-    padding: 20px 0 20px 20px;
-  }
-}
-
-/**
-* Theme display with vertical toolbar.
-*/
-@media screen and (min-width: 60em) {
-  .toolbar-vertical .system-themes-list-enabled .screenshot,
-  .toolbar-vertical .system-themes-list-enabled .no-screenshot {
-    float: right;
-    margin: 0 0 0 20px;
-  }
-  .toolbar-vertical .system-themes-list-disabled .theme-selector {
-    float: right;
-    padding: 20px 0 20px 20px;
-  }
-}
-.theme-selector .operations li {
-  float: right;
-  border-left: 1px solid #cdcdcd;
-  border-right: none;
-}
-.theme-selector .operations li.last {
-  padding: 0 0.7em 0 0;
-  border-left: none;
-}
-.theme-selector .operations li.first {
-  padding: 0 0 0 0.7em;
-}
-
-/**
- * Exposed filters.
- */
-.exposed-filters .filters {
-  float: right;
-  margin-left: 1em;
-  margin-right: 0;
-}
-.exposed-filters .form-item label {
-  float: right;
-}
-/* Current filters */
-.exposed-filters .additional-filters {
-  float: right;
-  margin-left: 1em;
-  margin-right: 0;
-}
diff --git a/core/modules/system/css/system.admin.css b/core/modules/system/css/system.admin.css
index b0c893c..c600539 100644
--- a/core/modules/system/css/system.admin.css
+++ b/core/modules/system/css/system.admin.css
@@ -17,6 +17,9 @@ div.admin-panel .description {
 div.admin-panel .body {
   padding: 0 4px 2px 8px; /* LTR */
 }
+[dir=rtl] div.admin-panel .body {
+  padding: 0 8px 2px 4px;
+}
 div.admin {
   padding-top: 15px;
 }
@@ -26,17 +29,34 @@ div.admin {
     width: 47%;
     margin-left: 1em; /* LTR */
   }
+  [dir=rtl] div.admin .left {
+    float: right;
+    margin-left: 0;
+    margin-right: 1em;
+  }
   div.admin .right {
     float: right; /* LTR */
     width: 47%;
     margin-right: 1em; /* LTR */
   }
+  [dir=rtl] div.admin .right {
+    float: left;
+    margin-left: 1em;
+    margin-right: 0;
+  }
 }
 div.admin .expert-link {
   text-align: right; /* LTR */
   margin-right: 1em; /* LTR */
   padding-right: 4px; /* LTR */
 }
+[dir=rtl] div.admin .expert-link {
+  margin-right: 0;
+  margin-left: 1em;
+  padding-right: 0;
+  padding-left: 4px;
+  text-align: left;
+}
 
 /**
  * Markup generated by theme_system_compact_link().
@@ -177,6 +197,10 @@ table.system-status-report td.status-icon {
   width: 16px;
   padding-right: 0; /* LTR */
 }
+[dir=rtl] table.system-status-report td.status-icon {
+  padding-left: 0;
+  padding-right: 6px;
+}
 table.system-status-report td.status-icon div {
   background-repeat: no-repeat;
   height: 16px;
@@ -266,6 +290,11 @@ table.system-status-report .status-title {
     margin: 0 20px 0 0; /* LTR */
     width: 294px;
   }
+  [dir=rtl] body:not(.toolbar-vertical) .system-themes-list-enabled .screenshot,
+  [dir=rtl] body:not(.toolbar-vertical) .system-themes-list-enabled .no-screenshot {
+    float: right;
+    margin: 0 0 0 20px;
+  }
   body:not(.toolbar-vertical) .system-themes-list-enabled h3 {
     margin-top: 0;
   }
@@ -277,6 +306,10 @@ table.system-status-report .status-title {
     float: left; /* LTR */
     padding: 20px 20px 20px 0; /* LTR */
   }
+  [dir=rtl] body:not(.toolbar-vertical) .system-themes-list-disabled .theme-selector {
+    float: right;
+    padding: 20px 0 20px 20px;
+  }
   body:not(.toolbar-vertical) .system-themes-list-disabled .theme-info {
     min-height: 170px;
   }
@@ -303,6 +336,11 @@ table.system-status-report .status-title {
     margin: 0 20px 0 0; /* LTR */
     width: 294px;
   }
+  [dir=rtl] .toolbar-vertical .system-themes-list-enabled .screenshot,
+  [dir=rtl] .toolbar-vertical .system-themes-list-enabled .no-screenshot {
+    float: right;
+    margin: 0 0 0 20px;
+  }
   .toolbar-vertical .system-themes-list-enabled h3 {
     margin-top: 0;
   }
@@ -314,6 +352,10 @@ table.system-status-report .status-title {
     float: left; /* LTR */
     padding: 20px 20px 20px 0; /* LTR */
   }
+  [dir=rtl] .toolbar-vertical .system-themes-list-disabled .theme-selector {
+    float: right;
+    padding: 20px 0 20px 20px;
+  }
   .toolbar-vertical .system-themes-list-disabled .theme-info {
     min-height: 170px;
   }
@@ -348,13 +390,25 @@ table.system-status-report .status-title {
   list-style-type: none;
   border-right: 1px solid #cdcdcd;  /* LTR */
 }
+[dir=rtl] .theme-selector .operations li {
+  float: right;
+  border-left: 1px solid #cdcdcd;
+  border-right: none;
+}
 .theme-selector .operations li.last {
   padding: 0 0 0 0.7em; /* LTR */
   border-right: none; /* LTR */
 }
+[dir=rtl] .theme-selector .operations li.last {
+  padding: 0 0.7em 0 0;
+  border-left: none;
+}
 .theme-selector .operations li.first {
   padding: 0 0.7em 0 0; /* LTR */
 }
+[dir=rtl] .theme-selector .operations li.first {
+  padding: 0 0 0 0.7em;
+}
 #system-themes-admin-form {
   clear: left;
 }
@@ -366,6 +420,11 @@ table.system-status-report .status-title {
   float: left; /* LTR */
   margin-right: 1em; /* LTR */
 }
+[dir=rtl] .exposed-filters .filters {
+  float: right;
+  margin-left: 1em;
+  margin-right: 0;
+}
 .exposed-filters .form-item {
   margin: 0 0 0.1em 0;
   padding: 0;
@@ -375,6 +434,9 @@ table.system-status-report .status-title {
   font-weight: normal;
   width: 10em;
 }
+[dir=rtl] .exposed-filters .form-item label {
+  float: right;
+}
 .exposed-filters .form-select {
   width: 14em;
 }
@@ -390,3 +452,8 @@ table.system-status-report .status-title {
   float: left; /* LTR */
   margin-right: 1em; /* LTR */
 }
+[dir=rtl] .exposed-filters .additional-filters {
+  float: right;
+  margin-left: 1em;
+  margin-right: 0;
+}
diff --git a/core/modules/system/css/system.module-rtl.css b/core/modules/system/css/system.module-rtl.css
deleted file mode 100644
index d01792e..0000000
--- a/core/modules/system/css/system.module-rtl.css
+++ /dev/null
@@ -1,55 +0,0 @@
-
-/**
- * @file
- * Generic theme-independent base styles.
- */
-
-/**
- * Autocomplete.
- */
-/* Animated throbber */
-.js input.form-autocomplete {
-  background-position: 0% 2px;
-}
-.js input.throbbing {
-  background-position: 0% -18px;
-}
-
-/**
- * Progress bar.
- */
-.progress .percentage {
-  float: left;
-}
-.progress-disabled {
-  float: right;
-}
-.ajax-progress {
-  float: right;
-}
-
-/**
- * TableDrag behavior.
- */
-.draggable a.tabledrag-handle {
-  float: right;
-  margin-right: -1em;
-  margin-left: 0;
-}
-a.tabledrag-handle .handle {
-  margin: -0.4em 0.5em;
-  padding: 0.42em 0.5em;
-}
-div.indentation {
-  float: right;
-  margin: -0.4em -0.4em -0.4em 0.2em;
-  padding: 0.42em 0.6em 0.42em 0;
-}
-div.tree-child,
-div.tree-child-last {
-  background-position: -65px center;
-}
-.tabledrag-toggle-weight-wrapper {
-  text-align: left;
-}
-
diff --git a/core/modules/system/css/system.module.css b/core/modules/system/css/system.module.css
index 2e92836..cf08f02 100644
--- a/core/modules/system/css/system.module.css
+++ b/core/modules/system/css/system.module.css
@@ -34,9 +34,15 @@
   background-position: 100% 2px; /* LTR */
   background-repeat: no-repeat;
 }
+.js[dir=rtl] input.form-autocomplete {
+  background-position: 0% 2px;
+}
 .js input.throbbing {
   background-position: 100% -18px; /* LTR */
 }
+.js[dir=rtl] input.throbbing {
+  background-position: 0% -18px;
+}
 
 /**
  * Collapsible details.
@@ -91,6 +97,11 @@ body.drag {
   overflow: hidden;
   text-decoration: none;
 }
+[dir=rtl] .draggable a.tabledrag-handle {
+  float: right;
+  margin-right: -1em;
+  margin-left: 0;
+}
 a.tabledrag-handle:hover {
   text-decoration: none;
 }
@@ -101,6 +112,10 @@ a.tabledrag-handle .handle {
   padding: 0.42em 0.5em; /* LTR */
   width: 13px;
 }
+[dir=rtl] a.tabledrag-handle .handle {
+  margin: -0.4em 0.5em;
+  padding: 0.42em 0.5em;
+}
 .touch .draggable td {
   padding: 0 10px;
 }
@@ -130,18 +145,30 @@ div.indentation {
   padding: 0.42em 0 0.42em 0.6em; /* LTR */
   width: 20px;
 }
+[dir=rtl] div.indentation {
+  float: right;
+  margin: -0.4em -0.4em -0.4em 0.2em;
+  padding: 0.42em 0.6em 0.42em 0;
+}
 div.tree-child {
   background: url(../../../misc/tree.png) no-repeat 11px center; /* LTR */
 }
 div.tree-child-last {
   background: url(../../../misc/tree-bottom.png) no-repeat 11px center; /* LTR */
 }
+[dir=rtl] div.tree-child,
+[dir=rtl] div.tree-child-last {
+  background-position: -65px center;
+}
 div.tree-child-horizontal {
   background: url(../../../misc/tree.png) no-repeat -11px center;
 }
 .tabledrag-toggle-weight-wrapper {
   text-align: right; /* LTR */
 }
+[dir=rtl] .tabledrag-toggle-weight-wrapper {
+  text-align: left;
+}
 
 /**
  * TableHeader behavior.
@@ -172,11 +199,20 @@ table.sticky-header {
 .progress .percentage {
   float: right; /* LTR */
 }
+[dir=rtl] .progress .percentage {
+  float: left;
+}
+[dir=rtl] .progress-disabled {
+  float: right;
+}
 /* Throbber */
 .ajax-progress {
   display: inline-block;
   padding: 1px 5px 2px 5px;
 }
+[dir=rtl] .ajax-progress {
+  float: right;
+}
 .ajax-progress-throbber .throbber {
   background: transparent url(../../../misc/throbber.gif) no-repeat 0px -18px;
   display: inline;
diff --git a/core/modules/system/css/system.theme-rtl.css b/core/modules/system/css/system.theme-rtl.css
deleted file mode 100644
index 789d908..0000000
--- a/core/modules/system/css/system.theme-rtl.css
+++ /dev/null
@@ -1,115 +0,0 @@
-
-/**
- * @file
- * RTL styles for common markup.
- */
-
-/**
- * HTML elements.
- */
-th {
-  text-align: right;
-  padding-left: 1em;
-  padding-right: 0;
-}
-caption {
-  text-align: right;
-}
-
-/**
- * Markup generated by theme_item_list().
- */
-.item-list ul li {
-  margin: 0 1.5em 0.25em 0;
-}
-
-/**
- * Markup generated by theme_more_link().
- */
-.more-link {
-  text-align: left;
-}
-
-/**
- * Markup generated by theme_more_help_link().
- */
-.more-help-link {
-  text-align: left;
-}
-.more-help-link a {
-  background-position: 100% 50%;
-  padding: 1px 20px 1px 0;
-}
-
-/**
- * Collapsible details.
- */
-.collapse-processed > summary:before {
-  background-position: 100% 100%;
-  float: right;
-}
-.collapse-processed:not([open]) > summary:before {
-  background-position: 75% 35%;
-  -moz-transform: rotate(90deg);
-  -ms-transform: rotate(90deg);
-  -o-transform: rotate(90deg);
-  -webkit-transform: rotate(90deg);
-  transform: rotate(90deg);
-}
-
-/**
- * RTL styles for menus and navigation markup.
- */
-
-ul.menu {
-  margin-left: 0;
-  margin-right: 1em;
-  text-align: right;
-}
-.menu .collapsed {
-  list-style-image: url(../../../misc/menu-collapsed-rtl.png);
-}
-
-/**
- * Markup generated by theme_menu_local_tasks().
- */
-.tabs > li {
-  margin-left: 0.3em;
-  margin-right: 0;
-}
-
-/**
- * RTL Styles for link buttons and action links.
- */
-.action-links li:first-child {
-  margin-left: 0.3em;
-  margin-right: 0;
-}
-.button-action:before {
-  margin-left: 0;
-  margin-right: -0.1em;
-  padding-left: 0.2em;
-  padding-right: 0;
-}
-
-/**
- * RTL Styles for system messages.
- */
-.messages {
-  border-width: 1px 8px 1px 1px;
-  background-position-x: 99%;
-  padding-left: 20px;
-  padding-right: 35px;
-  text-align: right;
-}
-.messages--status {
-  background-position: 99.3% 19px;
-  border-color: #c9e1bd #77b259 #c9e1bd #c9e1bd;
-}
-.messages--warning {
-  border-color: #f4daa6 #e09600 #f4daa6 #f4daa6;
-}
-.messages--error {
-  border-color: #f9c9bf #e62600 #f9c9bf #f9c9bf;
-}
-
diff --git a/core/modules/system/css/system.theme.css b/core/modules/system/css/system.theme.css
index 19bb45f..af122e5 100644
--- a/core/modules/system/css/system.theme.css
+++ b/core/modules/system/css/system.theme.css
@@ -33,6 +33,11 @@ th {
   padding-right: 1em; /* LTR */
   text-align: left; /* LTR */
 }
+[dir=rtl] th {
+  text-align: right;
+  padding-left: 1em;
+  padding-right: 0;
+}
 thead > tr {
   border-bottom: 1px solid #000;
 }
@@ -43,6 +48,9 @@ tr {
 caption {
   text-align: left; /* LTR */
 }
+[dir=rtl] caption {
+  text-align: right;
+}
 
 /**
  * Publishing status.
@@ -78,6 +86,9 @@ td.active {
   margin: 0 0 0.25em 1.5em; /* LTR */
   padding: 0;
 }
+[dir=rtl] .item-list ul li {
+  margin: 0 1.5em 0.25em 0;
+}
 
 /**
  * Markup generated by Form API.
@@ -164,6 +175,9 @@ abbr.form-required, abbr.tabledrag-changed, abbr.ajax-changed {
 .more-link {
   text-align: right; /* LTR */
 }
+[dir=rtl] .more-link {
+  text-align: left;
+}
 
 /**
  * Markup generated by theme_more_help_link().
@@ -171,10 +185,17 @@ abbr.form-required, abbr.tabledrag-changed, abbr.ajax-changed {
 .more-help-link {
   text-align: right; /* LTR */
 }
+[dir=rtl] .more-help-link {
+  text-align: left;
+}
 .more-help-link a {
   background: url(../../../misc/help.png) 0 50% no-repeat; /* LTR */
   padding: 1px 0 1px 20px; /* LTR */
 }
+[dir=rtl] .more-help-link a {
+  background-position: 100% 50%;
+  padding: 1px 20px 1px 0;
+}
 
 /**
  * Markup generated by theme_pager().
@@ -251,6 +272,10 @@ summary {
   height: 1em;
   width: 1em;
 }
+[dir=rtl] .collapse-processed > summary:before {
+  background-position: 100% 100%;
+  float: right;
+}
 .collapse-processed:not([open]) > summary:before {
   background-position: 25% 35%; /* LTR */
   -moz-transform: rotate(-90deg);
@@ -259,6 +284,14 @@ summary {
   -webkit-transform: rotate(-90deg);
   transform: rotate(-90deg);
 }
+[dir=rtl] .collapse-processed:not([open]) > summary:before {
+  background-position: 75% 35%;
+  -moz-transform: rotate(90deg);
+  -ms-transform: rotate(90deg);
+  -o-transform: rotate(90deg);
+  -webkit-transform: rotate(90deg);
+  transform: rotate(90deg);
+}
 
 /**
  * TableDrag behavior.
@@ -315,6 +348,11 @@ ul.menu {
   padding: 0;
   text-align: left; /* LTR */
 }
+[dir=rtl] ul.menu {
+  margin-left: 0;
+  margin-right: 1em;
+  text-align: right;
+}
 .menu .expanded {
   list-style-image: url(../../../misc/menu-expanded.png);
   list-style-type: circle;
@@ -323,6 +361,9 @@ ul.menu {
   list-style-image: url(../../../misc/menu-collapsed.png); /* LTR */
   list-style-type: disc;
 }
+[dir=rtl] .menu .collapsed {
+  list-style-image: url(../../misc/menu-collapsed-rtl.png);
+}
 ul.menu li {
   padding-top: 0.2em;
   margin: 0;
@@ -384,6 +425,10 @@ ul.tabs {
   display: inline-block;
   margin-right: 0.3em; /* LTR */
 }
+[dir=rtl] .tabs > li {
+  margin-left: 0.3em;
+  margin-right: 0;
+}
 .tabs a {
   display: block;
   padding: 0.2em 1em;
@@ -412,6 +457,10 @@ ul.tabs {
 .action-links li:first-child {
   margin-left: 0; /* LTR */
 }
+[dir=rtl] .action-links li:first-child {
+  margin-left: 0.3em;
+  margin-right: 0;
+}
 .button-action {
   display: inline-block;
   line-height: 160%;
@@ -424,6 +473,12 @@ ul.tabs {
   margin-left: -0.1em; /* LTR */
   padding-right: 0.2em; /* LTR */
 }
+[dir=rtl] .button-action:before {
+  margin-left: 0;
+  margin-right: -0.1em;
+  padding-left: 0.2em;
+  padding-right: 0;
+}
 
 /**
  * Styles for system messages.
@@ -437,6 +492,13 @@ ul.tabs {
   word-wrap: break-word;
   overflow-wrap: break-word;
 }
+[dir=rtl] .messages {
+  border-width: 1px 8px 1px 1px;
+  background-position-x: 99%;
+  padding-left: 20px;
+  padding-right: 35px;
+  text-align: right;
+}
 .messages + .messages {
   margin-top: 1.538em;
 }
@@ -455,6 +517,10 @@ ul.tabs {
   background-image: url(../../../misc/message-16-ok.png);
   background-position: 12px 19px;  /* LTR */
 }
+[dir=rtl] .messages--status {
+  background-position: 99.3% 19px;
+  border-color: #c9e1bd #77b259 #c9e1bd #c9e1bd;
+}
 .messages--status,
 .ok {
   color: #325e1c;
@@ -468,6 +534,9 @@ table tr.ok {
   background-image: url(../../../misc/message-16-warning.png);
   border-color: #f4daa6 #f4daa6 #f4daa6 #e09600;  /* LTR */
 }
+[dir=rtl] .messages--warning {
+  border-color: #f4daa6 #e09600 #f4daa6 #f4daa6;
+}
 .messages--warning,
 .warning {
   color: #734c00;
@@ -481,6 +550,9 @@ table tr.warning {
   background-image: url(../../../misc/message-16-error.png);
   border-color: #f9c9bf #f9c9bf #f9c9bf #e62600;  /* LTR */
 }
+[dir=rtl] .messages--error {
+  border-color: #f9c9bf #e62600 #f9c9bf #f9c9bf;
+}
 .messages--error,
 .error {
   color: #a51b00;
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/CascadingStylesheetsTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/CascadingStylesheetsTest.php
index 57d9353..b162c3b 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/CascadingStylesheetsTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/CascadingStylesheetsTest.php
@@ -204,24 +204,6 @@ function testRenderOverride() {
   }
 
   /**
-   * Tests Locale module's CSS Alter to include RTL overrides.
-   */
-  function testAlter() {
-    // Switch the language to a right to left language and add system.module.css.
-    $language_interface = language(Language::TYPE_INTERFACE);
-    $language_interface->direction = Language::DIRECTION_RTL;
-    $path = drupal_get_path('module', 'system');
-    drupal_add_css($path . '/css/system.module.css');
-
-    // Check to see if system.module-rtl.css was also added.
-    $styles = drupal_get_css();
-    $this->assert(strpos($styles, $path . '/css/system.module-rtl.css') !== FALSE, 'CSS is alterable as right to left overrides are added.');
-
-    // Change the language back to left to right.
-    $language_interface->direction = Language::DIRECTION_LTR;
-  }
-
-  /**
    * Tests that CSS query string remains intact when added to file.
    */
   function testAddCssFileWithQueryString() {
diff --git a/core/modules/toolbar/css/toolbar.icons-rtl.css b/core/modules/toolbar/css/toolbar.icons-rtl.css
deleted file mode 100644
index aadd333..0000000
--- a/core/modules/toolbar/css/toolbar.icons-rtl.css
+++ /dev/null
@@ -1,43 +0,0 @@
-/**
- * @file toolbar.icons-rtl.css
- */
-.toolbar .icon {
-  padding-left: 1.3333em;
-  padding-right: 2.75em;
-}
-.toolbar .icon:before {
-  left: auto;
-  right: 0.6667em;
-}
-.toolbar .menu ul .icon {
-  padding-left: 0;
-  padding-right: 1.3333em;
-}
-.toolbar .vertical .menu ul {
-  margin-left: 0;
-  margin-right: 1.5em;
-}
-.toolbar .vertical .menu ul ul {
-  margin-left: 0;
-  margin-right: 0.75em;
-}
-
-@media only screen and (min-width: 16.5em) {
-  .toolbar .bar .icon:before {
-    background-size: auto auto;
-    left: auto;
-    right: 0;
-  }
-}
-
-@media only screen and (min-width: 36em) {
-  .toolbar .bar .icon {
-    background-position: right center;
-    padding-left: 1.3333em;
-    padding-right: 2.75em;
-  }
-  .toolbar .bar .icon:before {
-    left: 0;
-    right: 0.6667em;
-  }
-}
diff --git a/core/modules/toolbar/css/toolbar.icons.css b/core/modules/toolbar/css/toolbar.icons.css
index 7fc06bf..dc457ca 100644
--- a/core/modules/toolbar/css/toolbar.icons.css
+++ b/core/modules/toolbar/css/toolbar.icons.css
@@ -5,6 +5,10 @@
   padding-left: 2.75em; /* LTR */
   position: relative;
 }
+[dir=rtl] .toolbar .icon {
+  padding-left: 1.3333em;
+  padding-right: 2.75em;
+}
 .toolbar .icon:before {
   background-attachment: scroll;
   background-color: transparent;
@@ -18,6 +22,10 @@
   top: 0;
   width: 20px;
 }
+[dir=rtl] .toolbar .icon:before {
+  left: auto;
+  right: 0.6667em;
+}
 .toolbar button.icon {
   background-color: transparent;
   border: 0;
@@ -26,15 +34,27 @@
 .toolbar .menu ul .icon {
   padding-left: 1.3333em; /* LTR */
 }
+[dir=rtl] .toolbar .menu ul .icon {
+  padding-left: 0;
+  padding-right: 1.3333em;
+}
 .toolbar .menu ul a.icon:before {
   display: none;
 }
 .toolbar .vertical .menu ul {
   margin-left: 1.5em; /* LTR */
 }
+[dir=rtl] .toolbar .vertical .menu ul {
+  margin-left: 0;
+  margin-right: 1.5em;
+}
 .toolbar .vertical .menu ul ul {
   margin-left: 0.75em; /* LTR */
 }
+[dir=rtl] .toolbar .vertical .menu ul ul {
+  margin-left: 0;
+  margin-right: 0.75em;
+}
 
 /**
  * Top level icons
@@ -127,6 +147,11 @@
     left: 0; /* LTR */
     width: 100%;
   }
+  [dir=rtl] .toolbar .bar .icon:before {
+    background-size: auto auto;
+    left: auto;
+    right: 0;
+  }
 }
 
 @media only screen and (min-width: 36em) {
@@ -137,8 +162,17 @@
     text-indent: 0;
     width: auto;
   }
+  [dir=rtl] .toolbar .bar .icon {
+    background-position: right center;
+    padding-left: 1.3333em;
+    padding-right: 2.75em;
+  }
   .toolbar .bar .icon:before {
     left: 0.6667em; /* LTR */
     width: 20px;
   }
+  [dir=rtl] .toolbar .bar .icon:before {
+    left: 0;
+    right: 0.6667em;
+  }
 }
diff --git a/core/modules/toolbar/css/toolbar.menu-rtl.css b/core/modules/toolbar/css/toolbar.menu-rtl.css
deleted file mode 100644
index 1435225..0000000
--- a/core/modules/toolbar/css/toolbar.menu-rtl.css
+++ /dev/null
@@ -1,19 +0,0 @@
-/**
- * @file toolbar.menu-rtl.css
- */
-.toolbar .vertical .handle + a {
-  margin-left: 3em;
-  margin-right: 0;
-}
-
-/**
- * Handle.
- */
-.toolbar .icon.handle {
-  left: 0;
-  right: auto;
-}
-.toolbar .icon.handle:before {
-  left: auto;
-  right: 0;
-}
diff --git a/core/modules/toolbar/css/toolbar.menu.css b/core/modules/toolbar/css/toolbar.menu.css
index c77c4c5..39f214d 100644
--- a/core/modules/toolbar/css/toolbar.menu.css
+++ b/core/modules/toolbar/css/toolbar.menu.css
@@ -23,6 +23,10 @@
 .toolbar .vertical .handle + a {
   margin-right: 3em; /* LTR */
 }
+[dir=rtl] .toolbar .vertical .handle + a {
+  margin-left: 3em;
+  margin-right: 0;
+}
 .toolbar .tray .active-trail > .box a,
 .toolbar .tray a.active {
   color: #000;
@@ -86,10 +90,18 @@
   width: 3em;
   z-index: 1;
 }
+[dir=rtl] .toolbar .icon.handle {
+  left: 0;
+  right: auto;
+}
 .toolbar .icon.handle:before {
   background-image: url("../images/icon-open.png");
   left: 0; /* LTR */
 }
+[dir=rtl] .toolbar .icon.handle:before {
+  left: auto;
+  right: 0;
+}
 .toolbar .icon.handle.open:before {
   background-image: url("../images/icon-collapse.png");
 }
diff --git a/core/modules/toolbar/css/toolbar.module-rtl.css b/core/modules/toolbar/css/toolbar.module-rtl.css
deleted file mode 100644
index ae80d8a..0000000
--- a/core/modules/toolbar/css/toolbar.module-rtl.css
+++ /dev/null
@@ -1,78 +0,0 @@
-/**
- * @file toolbar.module-rtl.css
- */
-html.js .toolbar {
-  left: auto;
-  right: 0;
-}
-.js .toolbar .bar .tab {
-  float: right;
-}
-
-/**
- * Administration menu.
- */
-.js .toolbar .bar {
-  left: auto;
-  right: 0;
-}
-@media only screen {
-  .js .toolbar .bar .tab,
-  .js .toolbar .tray li {
-    float: none;
-  }
-}
-@media only screen and (min-width: 16.5em) {
-  .js .toolbar .bar .tab,
-  .js .toolbar .horizontal li {
-    float: right;
-  }
-}
-
-/**
- * Toolbar tray.
- */
-.toolbar .vertical {
-  left: auto;
-  right: -100%;
-}
-.toolbar .horizontal {
-  left: auto;
-  right: 0;
-}
-.toolbar .vertical > .lining {
-  left: auto;
-  right: -100%;
-}
-.toolbar .vertical.active,
-.toolbar .vertical.active > .lining {
-  left: auto;
-  right: 0;
-}
-@media only screen and (min-width: 16.5em) {
-  .toolbar .vertical.active > .lining:before {
-    left: auto;
-    right: -1px;
-  }
-}
-
-/**
- * At larger screen sizes, the tray pushes the page content.
- */
-@media only screen and (min-width: 38.125em) {
-  body.toolbar-tray-open.toolbar-vertical {
-    margin-left: 0;
-    margin-right: 240px;
-    margin-right: 15rem;
-  }
-}
-/**
- * ToolBar tray orientation toggle.
- */
-.toolbar .horizontal .toggle-orientation {
-  left: 0;
-  right: auto;
-}
-.toolbar .vertical .toggle-orientation {
-  float: left;
-}
diff --git a/core/modules/toolbar/css/toolbar.module.css b/core/modules/toolbar/css/toolbar.module.css
index 9406f86..be20fdc 100644
--- a/core/modules/toolbar/css/toolbar.module.css
+++ b/core/modules/toolbar/css/toolbar.module.css
@@ -25,6 +25,11 @@ html.js .toolbar {
   top: 0;
   width: 100%;
 }
+html.js[dir=rtl] .toolbar {
+   left: auto;
+   right: 0;
+ }
+
 /**
  * Very specific overrides for Drupal system CSS.
  */
@@ -47,6 +52,10 @@ html.js .toolbar {
 .js .toolbar .horizontal .tab  {
   float: left; /* LTR */
 }
+.js[dir=rtl] .toolbar .bar .tab,
+.js[dir=rtl] .toolbar .horizontal .tab {
+  float: right;
+}
 .js .toolbar a {
   display: block;
   line-height: 1;
@@ -61,17 +70,29 @@ html.js .toolbar {
   z-index: 1250;
   width: 100%;
 }
+.js[dir=rtl] .toolbar .bar {
+  left: auto;
+  right: 0;
+}
 @media only screen {
   .js .toolbar .bar .tab,
   .js .toolbar .tray li {
     float: none; /* LTR */
   }
+  .js[dir=rtl] .toolbar .bar .tab,
+  .js[dir=rtl] .toolbar .tray li {
+    float: none;
+  }
 }
 @media only screen and (min-width: 16.5em) {
   .js .toolbar .bar .tab,
   .js .toolbar .horizontal li {
     float: left; /* LTR */
   }
+  .js[dir=rtl] .toolbar .bar .tab,
+  .js[dir=rtl] .toolbar .horizontal li {
+    float: right;
+  }
 }
 @media only screen and (min-width: 28.125em) {
   .js .toolbar .bar {
@@ -106,12 +127,20 @@ html.js .toolbar {
   left: -100%; /* LTR */
   position: absolute;
 }
+[dir=rtl] .toolbar .vertical {
+  left: auto;
+  right: -100%;
+}
 .toolbar .horizontal {
   left: 0; /* LTR */
   height: 0;
   /* Set one higher than the contextual links gear. */
   z-index: 1000;
 }
+[dir=rtl] .toolbar .horizontal {
+  left: auto;
+  right: 0;
+}
 .toolar .tray .lining {
   position: relative;
 }
@@ -124,6 +153,11 @@ html.js .toolbar {
   position: absolute;
   width: 100%;
 }
+[dir=rtl] .toolbar .vertical > .lining,
+[dir=rtl] .toolbar .vertical > .lining:before {
+  left: auto;
+  right: -100%;
+}
 .toolbar .vertical > .lining:before {
   bottom: 0;
   -moz-box-sizing: content-box;
@@ -151,6 +185,11 @@ html.js .toolbar {
   left: 0; /* LTR */
   top: 0;
 }
+[dir=rtl] .toolbar .vertical.active,
+[dir=rtl] .toolbar .vertical.active > .lining {
+  left: auto;
+  right: 0;
+}
 /* Make vertical toolbar tray scroll with page for touch devices. */
 .touch .toolbar .vertical.active,
 .touch .toolbar .vertical.active > .lining {
@@ -181,6 +220,10 @@ html.js .toolbar {
     display: block;
     left: -1px; /* LTR */
   }
+  [dir=rtl] .toolbar .vertical.active > .lining:before {
+    left: auto;
+    right: -1px;
+  }
 }
 @media only screen and (min-width: 28.125em) {
   .toolbar .tray.horizontal {
@@ -195,6 +238,11 @@ html.js .toolbar {
     margin-left: 240px; /* LTR */
     margin-left: 15rem; /* LTR */
   }
+  [dir=rtl] body.toolbar-tray-open.toolbar-vertical {
+    margin-left: 0;
+    margin-right: 240px;
+    margin-right: 15rem;
+  }
 }
 /**
  * ToolBar tray orientation toggle.
@@ -221,7 +269,14 @@ html.js .toolbar {
   right: 0; /* LTR */
   top: 0;
 }
+[dir=rtl] .toolbar .horizontal .toggle-orientation {
+  left: 0;
+  right: auto;
+}
 .toolbar .vertical .toggle-orientation {
   float: right; /* LTR */
   width: 100%;
 }
+[dir=rtl] .toolbar .vertical .toggle-orientation {
+  float: left;
+}
diff --git a/core/modules/toolbar/css/toolbar.theme-rtl.css b/core/modules/toolbar/css/toolbar.theme-rtl.css
deleted file mode 100644
index 031bc60..0000000
--- a/core/modules/toolbar/css/toolbar.theme-rtl.css
+++ /dev/null
@@ -1,65 +0,0 @@
-/**
- * @file toolbar.theme-rtl.css
- */
-
-/**
- * Toolbar bar.
- */
-.toolbar .bar {
-  box-shadow: 1px 0 3px 1px rgba(0, 0, 0, 0.3333);
-}
-/**
- * Toolbar tray.
- */
- .toolbar .horizontal {
-  box-shadow: 2px 1px 3px 1px rgba(0, 0, 0, 0.3333);
-}
-.toolbar .horizontal > .lining {
-  padding-right: 0;
-  padding-left: 5em;
-}
-.toolbar .vertical > .lining,
-.toolbar .vertical > .lining:before {
-  border-left: 1px solid #aaaaaa;
-  border-right: 0 none;
-}
-.toolbar .vertical > .lining:before {
-  box-shadow: 1px 0 5px 2px rgba(0, 0, 0, 0.3333);
-}
-.toolbar .horizontal .menu li + li {
-  border-left: 0 none ;
-  border-right: 1px solid #dddddd;
-}
-.toolbar .horizontal .menu li:last-child {
-  border-left: 1px solid #dddddd;
-}
-.toolbar .vertical .menu .menu .menu {
-  margin-left: 0;
-  margin-right: 1.3333em;
-}
-.toolbar .vertical .menu .menu .menu .menu {
-  margin-left: 0;
-  margin-right: 0.25em;
-}
-.toolbar .vertical .menu .menu .menu a {
-  padding-left: 0;
-  padding-right: 0.5em;
-}
-
-/**
- * Orientation toggle.
- */
-.toolbar .horizontal .toggle-orientation {
-  border-left: 0 none;
-  border-right: 1px solid #c9c9c9;
-}
-.toolbar .toggle-orientation > .lining {
-  float: left;
-}
-.toolbar .toggle-orientation button:before {
-  left: auto;
-  right: 0;
-}
-.toolbar .toggle-orientation [value="vertical"]:before {
-  background-image: url('../images/icon-toggle-vertical-rtl.png'); /* LTR */
-}
diff --git a/core/modules/toolbar/css/toolbar.theme.css b/core/modules/toolbar/css/toolbar.theme.css
index 4b1805f..9a50a3c 100644
--- a/core/modules/toolbar/css/toolbar.theme.css
+++ b/core/modules/toolbar/css/toolbar.theme.css
@@ -31,6 +31,9 @@
   box-shadow: -1px 0 3px 1px rgba(0, 0, 0, 0.3333); /* LTR */
   color: #dddddd;
 }
+[dir=rtl] .toolbar .bar {
+  box-shadow: 1px 0 3px 1px rgba(0, 0, 0, 0.3333);
+}
 .toolbar .bar a {
   color: #ffffff;
 }
@@ -56,18 +59,33 @@
 .toolbar .horizontal > .lining {
   padding-right: 5em; /* LTR */
 }
+[dir=rtl] .toolbar .horizontal > .lining {
+  padding-right: 0;
+  padding-left: 5em;
+}
 .toolbar .vertical > .lining,
 .toolbar .vertical > .lining:before {
   background-color: #ffffff;
   border-right: 1px solid #aaaaaa; /* LTR */
 }
+[dir=rtl] .toolbar .vertical > .lining,
+[dir=rtl] .toolbar .vertical > .lining:before {
+  border-left: 1px solid #aaaaaa;
+  border-right: 0 none;
+}
 .toolbar .vertical > .lining:before {
   box-shadow: -1px 0 5px 2px rgba(0, 0, 0, 0.3333); /* LTR */
 }
+[dir=rtl] .toolbar .vertical > .lining:before {
+  box-shadow: 1px 0 5px 2px rgba(0, 0, 0, 0.3333);
+}
 .toolbar .horizontal {
   border-bottom: 1px solid #aaaaaa;
   box-shadow: -2px 1px 3px 1px rgba(0, 0, 0, 0.3333); /* LTR */
 }
+[dir=rtl] .toolbar .horizontal {
+  box-shadow: 2px 1px 3px 1px rgba(0, 0, 0, 0.3333);
+}
 .toolbar .horizontal .tray {
   background-color: #f5f5f5;
 }
@@ -85,9 +103,16 @@
 .toolbar .horizontal .menu li + li {
   border-left: 1px solid #dddddd; /* LTR */
 }
+[dir=rtl] .toolbar .horizontal .menu li + li {
+  border-left: 0 none ;
+  border-right: 1px solid #dddddd;
+}
 .toolbar .horizontal .menu li:last-child {
   border-right: 1px solid #dddddd; /* LTR */
 }
+[dir=rtl] .toolbar .horizontal .menu li:last-child {
+  border-left: 1px solid #dddddd;
+}
 .toolbar .vertical .menu li + li {
   border-top: 1px solid #dddddd;
 }
@@ -107,15 +132,27 @@
 .toolbar .vertical .menu .menu .menu {
   margin-left: 1.3333em; /* LTR */
 }
+[dir=rtl] .toolbar .vertical .menu .menu .menu {
+  margin-left: 0;
+  margin-right: 1.3333em;
+}
 .toolbar .vertical .menu .menu .menu .menu {
   margin-left: 0.25em; /* LTR */
 }
+[dir=rtl] .toolbar .vertical .menu .menu .menu .menu {
+  margin-left: 0;
+  margin-right: 0.25em;
+}
 .toolbar .menu .menu a {
   color: #434343;
 }
 .toolbar .vertical .menu .menu .menu a {
   padding-left: 0.6667em; /* LTR */
 }
+[dir=rtl] .toolbar .vertical .menu .menu .menu a {
+  padding-left: 0;
+  padding-right: 0.5em;
+}
 
 /**
  * Orientation toggle.
@@ -127,10 +164,17 @@
 .toolbar .horizontal .toggle-orientation {
   border-left: 1px solid #c9c9c9; /* LTR */
 }
+[dir=rtl] .toolbar .horizontal .toggle-orientation {
+  border-left: 0 none;
+  border-right: 1px solid #c9c9c9;
+}
 .toolbar .toggle-orientation > .lining {
   float: right; /* LTR */
   padding: 0.1667em;
 }
+[dir=rtl] .toolbar .toggle-orientation > .lining {
+  float: left;
+}
 .toolbar .toggle-orientation button {
   cursor: pointer;
   display: inline-block;
@@ -142,9 +186,16 @@
 .toolbar .toggle-orientation button:before {
   left: 0; /* LTR */
 }
+[dir=rtl] .toolbar .toggle-orientation button:before {
+  left: auto;
+  right: 0;
+}
 .toolbar .toggle-orientation [value="vertical"]:before {
   background-image: url('../images/icon-toggle-vertical.png'); /* LTR */
 }
+[dir=rtl] .toolbar .toggle-orientation [value="vertical"]:before {
+  background-image: url('../images/icon-toggle-vertical-rtl.png'); /* LTR */
+}
 .toolbar .toggle-orientation [value="horizontal"]:before {
   background-image: url('../images/icon-toggle-horizontal.png');
 }
diff --git a/core/modules/tour/css/tour.module-rtl.css b/core/modules/tour/css/tour.module-rtl.css
deleted file mode 100644
index 5e19f7b..0000000
--- a/core/modules/tour/css/tour.module-rtl.css
+++ /dev/null
@@ -1,13 +0,0 @@
-/**
- * @file
- * RTL styling for tour module.
- */
-
-.js .toolbar .bar .tour-toolbar-tab.tab {
-  float: left;
-}
-
-.tour-progress {
-  right: 0;
-  left: 15px;
-}
diff --git a/core/modules/tour/css/tour.module.css b/core/modules/tour/css/tour.module.css
index 07033cd..529a661 100644
--- a/core/modules/tour/css/tour.module.css
+++ b/core/modules/tour/css/tour.module.css
@@ -7,6 +7,9 @@
 .js .toolbar .bar .tour-toolbar-tab.tab {
   float: right; /* LTR */
 }
+.js[dir=rtl] .toolbar .tour-toolbar-tab.tab {
+  float: left;
+}
 .js .toolbar .tour-toolbar-tab button {
   padding-bottom: 1em;
   padding-top: 1em;
@@ -32,6 +35,10 @@
   bottom: 10px;
   right: 15px; /* LTR */
 }
+[dir=rtl] .tour-progress {
+  right: 0;
+  left: 15px;
+}
 
 /* @todo Remove once http://drupal.org/node/1916690 is resolved. */
 .js .toolbar .tour-toolbar-tab.tab.hidden {
diff --git a/core/modules/update/css/update.admin-rtl.css b/core/modules/update/css/update.admin-rtl.css
deleted file mode 100644
index f181c84..0000000
--- a/core/modules/update/css/update.admin-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/css/update.admin.css b/core/modules/update/css/update.admin.css
index cb20500..231f86d 100644
--- a/core/modules/update/css/update.admin.css
+++ b/core/modules/update/css/update.admin.css
@@ -9,6 +9,9 @@
   padding-left: .25em; /* LTR */
   height: 22px;
 }
+[dir=rtl] .update .project {
+  padding-right: .25em;
+}
 
 .update .version-status {
   float: right; /* LTR */
@@ -16,10 +19,17 @@
   font-size: 110%;
   height: 20px;
 }
+[dir=rtl] .update .version-status {
+  float: left;
+  padding-left: 10px;
+}
 
 .update .version-status .icon {
   padding-left: .5em; /* LTR */
 }
+[dir=rtl] .update .version-status .icon {
+  padding-right: .5em;
+}
 
 .update .version-date {
   white-space: nowrap;
@@ -93,15 +103,26 @@ table.update,
   padding-left: 1em; /* LTR */
   width: 14em;
 }
+[dir=rtl] .update table.version .version-title {
+  padding-left: 1em;
+}
 
 .update table.version .version-details {
   padding-right: .5em; /* LTR */
 }
+[dir=rtl] .update table.version .version-details {
+  padding-left: .5em;
+  direction: ltr;
+}
 
 .update table.version .version-links {
   text-align: right; /* LTR */
   padding-right: 1em; /* LTR */
 }
+[dir=rtl] .update table.version .version-links {
+  text-align: left;
+  padding-left: 1em;
+}
 
 .update table.version-security .version-title {
   color: #970f00;
@@ -119,6 +140,9 @@ table.update,
 .update .check-manually {
   padding-left: 1em; /* LTR */
 }
+[dir=rtl] .update .check-manually {
+  padding-right: 1em;
+}
 
 .update-major-version-warning {
   color: #ff0000;
diff --git a/core/modules/user/css/user.module-rtl.css b/core/modules/user/css/user.module-rtl.css
deleted file mode 100644
index ec459b4..0000000
--- a/core/modules/user/css/user.module-rtl.css
+++ /dev/null
@@ -1,22 +0,0 @@
-
-#permissions td.permission {
-  padding-left: 0;
-  padding-right: 1.5em;
-}
-
-/**
- * Password strength indicator.
- */
-.password-strength {
-  float: left;
-}
-.password-strength-text {
-  float: left;
-}
-div.password-confirm {
-  float: left;
-}
-.confirm-parent,
-.password-parent {
-  clear: right;
-}
diff --git a/core/modules/user/css/user.module.css b/core/modules/user/css/user.module.css
index ce8b166..24cd259 100644
--- a/core/modules/user/css/user.module.css
+++ b/core/modules/user/css/user.module.css
@@ -4,6 +4,10 @@
 #permissions td.permission {
   padding-left: 1.5em; /* LTR */
 }
+[dir=rtl] #permissions td.permission {
+  padding-left: 0;
+  padding-right: 1.5em;
+}
 #permissions tr.odd .form-item,
 #permissions tr.even .form-item {
   white-space: normal;
@@ -20,6 +24,9 @@
   width: 17em;
   float: right;  /* LTR */
 }
+[dir=rtl] .password-strength {
+  float: left;
+}
 .password-strength-title {
   display: inline;
 }
@@ -27,6 +34,9 @@
   float: right; /* LTR */
   font-weight: bold;
 }
+[dir=rtl] .password-strength-text {
+  float: left;
+}
 .password-indicator {
   background-color: #c4c4c4;
   height: 0.3em;
@@ -47,6 +57,9 @@ div.password-confirm {
   visibility: hidden;
   width: 17em;
 }
+[dir=rtl] div.password-confirm {
+  float: left;
+}
 div.form-item div.password-suggestions {
   padding: 0.2em 0.5em;
   margin: 0.7em 0;
@@ -62,6 +75,10 @@ div.password-suggestions ul {
   margin: 0;
   width: 36.3em;
 }
+[dir=rtl] .confirm-parent,
+[dir=rtl] .password-parent {
+  clear: right;
+}
 
  /**
  * Password strength indicator on narrow viewport.
diff --git a/core/modules/user/lib/Drupal/user/Tests/UserPermissionsTest.php b/core/modules/user/lib/Drupal/user/Tests/UserPermissionsTest.php
index 3fc3b4b..71dd185 100644
--- a/core/modules/user/lib/Drupal/user/Tests/UserPermissionsTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/UserPermissionsTest.php
@@ -62,25 +62,16 @@ function testUserPermissionChanges() {
   }
 
   /**
-   * Test assigning of permissions for the administrator role.
+   * Test administrator role access.
    */
-  function testAdministratorRole() {
-    $this->drupalLogin($this->admin_user);
-    $this->drupalGet('admin/config/people/accounts');
+  function testAdministratorAccess() {
+    $this->assertFalse(user_access('feed llamas with bananas', $this->admin_user));
 
-    // Set the user's role to be the administrator role.
-    $edit = array();
-    $edit['user_admin_role'] = $this->rid;
-    $this->drupalPost('admin/config/people/accounts', $edit, t('Save configuration'));
+    // Turn $this->rid into the administrator role.
+    config('user.settings')->set('admin_role', $this->rid);
 
-    // Enable aggregator module and ensure the 'administer news feeds'
-    // permission is assigned by default.
-    $edit = array();
-    $edit['modules[Core][aggregator][enable]'] = TRUE;
-    // Aggregator depends on file module, enable that as well.
-    $edit['modules[Core][file][enable]'] = TRUE;
-    $this->drupalPost('admin/modules', $edit, t('Save configuration'));
-    $this->assertTrue(user_access('administer news feeds', $this->admin_user), 'The permission was automatically assigned to the administrator role');
+    // Now the user should have access.
+    $this->assertTrue(user_access('feed llamas with bananas', $this->admin_user));
   }
 
   /**
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index e0ef6e6..8cd1024 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -480,6 +480,12 @@ function user_access($string, AccountInterface $account = NULL) {
     return TRUE;
   }
 
+  // Users with the administrator role have all privileges.
+  $admin_role = config('user.settings')->get('admin_role');
+  if ($admin_role && in_array($admin_role, $account->roles)) {
+    return TRUE;
+  }
+
   // To reduce the number of SQL queries, we cache the user's permissions
   // in a static variable.
   // Use the advanced drupal_static() pattern, since this is called very often.
@@ -2407,25 +2413,6 @@ function user_form_field_ui_field_instance_edit_form_submit($form, &$form_state)
 }
 
 /**
- * Implements hook_modules_installed().
- */
-function user_modules_installed($modules) {
-  // Assign all available permissions to the administrator role.
-  $rid = config('user.settings')->get('admin_role');
-  if ($rid) {
-    $permissions = array();
-    foreach ($modules as $module) {
-      if ($module_permissions = module_invoke($module, 'permission')) {
-        $permissions = array_merge($permissions, array_keys($module_permissions));
-      }
-    }
-    if (!empty($permissions)) {
-      user_role_grant_permissions($rid, $permissions);
-    }
-  }
-}
-
-/**
  * Implements hook_modules_uninstalled().
  */
 function user_modules_uninstalled($modules) {
diff --git a/core/modules/views_ui/css/views_ui.admin-rtl.css b/core/modules/views_ui/css/views_ui.admin-rtl.css
deleted file mode 100644
index c79878f..0000000
--- a/core/modules/views_ui/css/views_ui.admin-rtl.css
+++ /dev/null
@@ -1,85 +0,0 @@
-/**
- * The .css file is intended to only contain positioning and size declarations
- * For example: display, position, float, clear, and overflow.
- */
-
-/* @group Inline lists */
-
-.horizontal > * {
-  float: right;
-}
-
-.horizontal.right {
-  float: left;
-}
-
-/* @end */
-
-/* @group Attachment details
- *
- * The attachment details section, its tabs for each section and the buttons
- * to add a new section
- */
-
-.form-actions {
-  float: left;
-}
-
-/* @end */
-
-/* @group Attachment details tabs
- *
- * The tabs that switch between sections
- */
-
-.views-displays .secondary > li {
-  float: right;
-}
-
-/* @end */
-
-/* @group Attachment details new section button */
-
-.views-displays .secondary .action-list {
-  left: auto;
-  right: 0;
-}
-
-/* @end */
-
-/* @group Attachment collapsible details */
-
-.views-display-tab summary {
-  left: auto;
-}
-
-/* @end */
-
-/* @group Attachment configuration columns */
-
-@media screen and (min-width:45em) { /* 720px */
-  .views-display-columns > * {
-    float: right;
-    margin-left: 0;
-    margin-right: 2%;
-  }
-
-  .views-display-columns > *:first-child {
-    margin-right: 0;
-  }
-}
-
-/* @end */
-
-/* @group Settings forms */
-
-.views-dependent {
-  margin-right: 1.5em;
-}
-
-.views-display-setting .label,
-.views-display-setting .views-ajax-link {
-  float: right;
-}
-
-/* @end */
diff --git a/core/modules/views_ui/css/views_ui.admin.css b/core/modules/views_ui/css/views_ui.admin.css
index c0a37566..6efdfd0 100644
--- a/core/modules/views_ui/css/views_ui.admin.css
+++ b/core/modules/views_ui/css/views_ui.admin.css
@@ -29,10 +29,16 @@
   clear: none;
   float: left; /* LTR */
 }
+[dir=rtl] .horizontal > * {
+  float: right;
+}
 
 .horizontal.right {
   float: right;
 }
+[dir=rtl] .horizontal.right {
+  float: left;
+}
 
 .horizontal label {
   position: absolute;
@@ -103,6 +109,10 @@
  * to add a new section
  */
 
+[dir=rtl] .form-actions {
+  float: left;
+}
+
 .form-edit .form-actions {
 }
 
@@ -129,6 +139,9 @@
   float: left; /* LTR */
   padding: 0;
 }
+[dir=rtl] .views-displays .secondary > li {
+  float: right;
+}
 
 .views-displays .secondary .open > a {
   position: relative;
@@ -174,6 +187,10 @@
   top: 23px;
   z-index: 50;
 }
+[dir=rtl] .views-displays .secondary .action-list {
+  left: auto;
+  right: 0;
+}
 
 .views-displays .secondary .action-list  li {
   display: block;
@@ -183,6 +200,10 @@
 
 /* @group Attachment collapsible details */
 
+[dir=rtl] .views-display-tab summary {
+  left: auto;
+}
+
 .views-display-columns details {
   border: none;
   margin: 0;
@@ -217,10 +238,18 @@
     margin-bottom: 0;
     width: 32%;
   }
+  [dir=rtl] .views-display-columns > * {
+    float: right;
+    margin-left: 0;
+    margin-right: 2%;
+  }
 
   .views-display-columns > *:first-child {
     margin-left: 0; /* LTR */
   }
+  [dir=rtl] .views-display-columns > *:first-child {
+    margin-right: 0;
+  }
 }
 
 /* @end */
@@ -292,11 +321,19 @@
 
 /* @group Settings forms */
 
+[dir=rtl] .views-dependent {
+  margin-right: 1.5em;
+}
+
 .views-display-setting .label,
 .views-display-setting .views-ajax-link {
   display: inline-block;
   float: left; /* LTR */
 }
+[dir=rtl] .views-display-setting .label,
+[dir=rtl] .views-display-setting .views-ajax-link {
+  float: right;
+}
 
 /* @end */
 
diff --git a/core/modules/views_ui/css/views_ui.admin.theme-rtl.css b/core/modules/views_ui/css/views_ui.admin.theme-rtl.css
deleted file mode 100644
index 6548a17..0000000
--- a/core/modules/views_ui/css/views_ui.admin.theme-rtl.css
+++ /dev/null
@@ -1,220 +0,0 @@
-/**
- * The .admin.theme.css file is intended to contain presentation declarations
- * including images, borders, colors, and fonts.
- */
-
-/* @end */
-
-/* @group Icons */
-
-.actions a,
-.views-admin .icon,
-.views-admin .icon-text {
-  background-position: right top;
-}
-
-/* Targets any element with an icon -> text combo */
-.views-admin .icon-text {
-  padding-right: 19px;
-}
-
-.views-admin .icon-linked {
-  background-position: right -153px;
-}
-
-.views-admin .icon-unlinked {
-  background-position: right -195px;
-}
-
-.actions .views-button-add {
-  background-position: right -39px;
-}
-
-.actions .views-button-rearrange {
-  background-position: right -96px;
-}
-
-.actions .views-button-add:hover {
-  background-position: right -58px;
-}
-
-.actions .views-button-rearrange:hover {
-  background-position: right -115px;
-}
-
-.actions .views-button-add:active {
-  background-position: right -77px;
-}
-
-.actions .views-button-rearrange:active {
-  background-position: right -134px;
-}
-
-.views-displays .icon-add {
-  background-position: right -3px;
-}
-
-.views-displays .secondary a:hover > .icon-add {
-  background-position: right -21px;
-}
-
-.views-displays .secondary .open a:hover > .icon-add {
-  background-position: right -3px;
-}
-
-/* @end */
-
-/* @group Forms */
-
-.form-submit + .form-submit,
-.views-admin a.button + a.button {
-  margin-right: 1em;
-}
-
-.container-inline > * + *,
-.container-inline .details-wrapper > * + * {
-  padding-left: 0;
-  padding-right: 4px;
-}
-
-.views-admin .form-type-checkbox + .form-wrapper {
-  margin-right: 16px;
-}
-
-/* @end */
-
-/* @group Lists */
-
-.horizontal > * + * {
-  margin-right: 9px;
-  padding-right: 9px;
-}
-
-/* @end */
-
-/* @group Attachments */
-
-.views-displays .secondary {
-  padding: 6px 8px 8px;
-}
-
-.views-displays .views-display-top > ul > li + li {
-  margin-right: 3px;
-}
-
-.views-displays .views-extra-actions {
-  left: 10px;
-}
-
-/* @end */
-
-/* @group Attachment details tabs
- *
- * The tabs that switch between sections
- */
-
-.views-displays .secondary .action-list  li:first-child {
-  -moz-border-radius: 7px 0 0 0;
-  -webkit-border-top-left-radius: 7px;
-  -webkit-border-top-right-radius: 0;
-  border-radius: 7px 0 0 0;
-}
-
-/* @end */
-
-/* @group Attachment collapsible details
- *
- * The attachment section is a collapsible details, but should not
- * have a border around it.
- */
-
-.views-display-tab summary {
-  left: auto;
-  right: -5px;
-}
-
-/* @end */
-
-/* @group Auto preview
- *
- * The auto-preview checkbox line. This may have more stuff added to it.
- */
-
-div.form-item-displays-live-preview {
-  text-align: left;
-}
-
-/* @end */
-
-/* @group Attachment buckets
- *
- * These are the individual "buckets," or boxes, inside the three columns in the
- * attachment details section.
- */
-
-.views-ui-display-tab-bucket .icon-text {
-  padding-right: 25px;
-}
-
-/* @end */
-
-/* @group Attachment bucket rows
- *
- * This is each row within one of the "boxes."
- */
-
-.views-display-setting .label {
-  margin-left: 3px;
-}
-
-/* @end */
-
-/* @group Modal dialog box
- *
- * The contents of the popup dialog on the views edit form.
- */
-
-#views-filterable-options-controls .form-item {
-  margin-left: 2%;
-}
-
-.views-ui-dialog #views-progress-indicator {
-  left: 10px;
-  right: auto;
-}
-
-/* @end */
-
-/* @group Rearrange filters
- *
- * Styling for the form that allows views filters to be rearranged.
- */
-.views-operator-label {
-  padding-right: 0.5em;
-}
-
-/* @end */
-
-/* @group Live preview elements */
-
-/* @group HTML list */
-
-#views-live-preview .view-content > .item-list > ul {
-  padding-right: 21px;
-}
-
-/* @end */
-
-/* @group Buttons */
-
-.no-js .views-display-top .dropbutton {
-  left: 12px;
-  right: auto;
-}
-
-.views-ui-display-tab-bucket .dropbutton {
-  left: 5px;
-  right: auto;
-}
-
-/* @end */
diff --git a/core/modules/views_ui/css/views_ui.admin.theme.css b/core/modules/views_ui/css/views_ui.admin.theme.css
index bce3fdc..ab5f0f0 100644
--- a/core/modules/views_ui/css/views_ui.admin.theme.css
+++ b/core/modules/views_ui/css/views_ui.admin.theme.css
@@ -44,6 +44,11 @@
   background-repeat: no-repeat;
 }
 
+[dir=rtl] .views-admin .icon,
+[dir=rtl] .views-admin .icon-text {
+  background-position: right top;
+}
+
 .views-admin a.icon {
   background-image:
     url("../images/sprites.png"),
@@ -105,13 +110,22 @@
 .views-admin .icon-text {
   padding-left: 19px; /* LTR */
 }
+[dir=rtl] .views-admin .icon-text {
+  padding-right: 19px;
+}
 
 .views-admin .icon.linked {
-  background-position: center -153px;
+  background-position: center -153px; /* LTR */
+}
+[dir=rtl] .views-admin .icon-linked {
+  background-position: right -153px;
 }
 
 .views-admin .icon.unlinked {
-  background-position: center -195px;
+  background-position: center -195px; /* LTR */
+}
+[dir=rtl] .views-admin .icon-unlinked {
+  background-position: right -195px;
 }
 
 .views-admin .icon.add {
@@ -141,10 +155,16 @@
 .views-displays .secondary a:hover > .icon.add {
   background-position: center -25px;
 }
+[dir=rtl] .views-displays .secondary a:hover > .icon-add {
+  background-position: right -21px;
+}
 
 .views-displays .secondary .open a:hover > .icon.add {
   background-position: center 3px;
 }
+[dir=rtl] .views-displays .secondary .open a:hover > .icon-add {
+  background-position: right -3px;
+}
 
 /* @end */
 
@@ -177,6 +197,10 @@ input.form-radio {
 .views-admin a.button:not(.js-hide) + a.button {
   margin-left: 1em; /* LTR */
 }
+[dir=rtl] .form-submit:not(.js-hide) + .form-submit,
+[dir=rtl] .views-admin a.button:not(.js-hide) + a.button {
+  margin-right: 1em;
+}
 
 .container-inline {
   padding-top: 15px;
@@ -186,6 +210,11 @@ input.form-radio {
 .container-inline .details-wrapper > * + * {
   padding-left: 4px; /* LTR */
 }
+[dir=rtl] .container-inline > * + *,
+[dir=rtl] .container-inline .details-wrapper > * + * {
+  padding-left: 0;
+  padding-right: 4px;
+}
 
 .views-admin details details.container-inline {
   margin-bottom: 1em;
@@ -201,6 +230,9 @@ input.form-radio {
 .views-admin .form-type-checkbox + .form-wrapper {
   margin-left: 16px; /* LTR */
 }
+[dir=rtl] .views-admin .form-type-checkbox + .form-wrapper {
+  margin-right: 16px;
+}
 
 /* Hide 'remove' checkboxes. */
 .views-remove-checkbox {
@@ -230,6 +262,10 @@ input.form-radio {
   margin-left: 9px; /* LTR */
   padding-left: 9px; /* LTR */
 }
+[dir=rtl] .horizontal > * + * {
+  margin-right: 9px;
+  padding-right: 9px;
+}
 
 .views-ui-view-title {
   font-weight: bold;
@@ -377,6 +413,10 @@ td.group-title {
   padding-left: 0.5em; /* LTR */
   text-transform: uppercase;
 }
+[dir=rtl] .views-operator-label {
+  padding-right: 0.5em;
+  padding-left: 0;
+}
 
 .grouped-description,
 .exposed-description {
@@ -719,6 +759,10 @@ ul#views-display-menu-tabs li.add ul.action-list li{
 .views-display-setting .label {
   margin-right: 3px; /* LTR */
 }
+[dir=rtl] .views-display-setting .label {
+  margin-left: 3px;
+  margin-right: 0;
+}
 
 /* @end */
 
@@ -826,6 +870,10 @@ ul#views-display-menu-tabs li.add ul.action-list li{
   width: 45%;
   margin-right: 2%; /* LTR */
 }
+[dir=rtl] #views-filterable-options-controls .form-item {
+  margin-left: 2%;
+  margin-right: 0;
+}
 
 #views-filterable-options-controls input,
 #views-filterable-options-controls select {
@@ -873,6 +921,10 @@ ul#views-display-menu-tabs li.add ul.action-list li{
   right: 10px; /* LTR */
   top: 8px;
 }
+[dir=rtl] .views-ui-dialog #views-progress-indicator {
+  left: 10px;
+  right: auto;
+}
 
 .views-ui-dialog #views-progress-indicator:before {
   content: "\003C\00A0";
@@ -1049,6 +1101,10 @@ ul#views-display-menu-tabs li.add ul.action-list li{
   list-style-position: outside;
   padding-left: 21px; /* LTR */
 }
+[dir=rtl] #views-live-preview .view-content > .item-list > ul {
+  padding-right: 21px;
+  padding-left: 0;
+}
 
 /* @end */
 
diff --git a/core/themes/bartik/css/layout-rtl.css b/core/themes/bartik/css/layout-rtl.css
deleted file mode 100644
index 77fe64b..0000000
--- a/core/themes/bartik/css/layout-rtl.css
+++ /dev/null
@@ -1,60 +0,0 @@
-
-/* ---------- Basic Layout RTL Styles ----------- */
-
-.region-header {
-  float: left;
-}
-#secondary-menu {
-  left: 0;
-  right: auto;
-}
-
-@media all and (min-width: 560px) and (max-width: 850px) {
-
-  #sidebar-first,
-  .region-triptych-first,
-  .region-triptych-middle,
-  .region-triptych-last,
-  .region-footer-firstcolumn,
-  .region-footer-secondcolumn,
-  .region-footer-thirdcolumn,
-  .region-footer-fourthcolumn {
-    float: right;
-  }
-  #sidebar-second {
-    margin-right: 50%;
-  }
-  .one-sidebar #sidebar-second {
-    margin-right: 0;
-  }
-}
-
-@media all and (min-width: 851px) {
-
-  #content,
-  #sidebar-first,
-  #sidebar-second,
-  .region-triptych-first,
-  .region-triptych-middle,
-  .region-triptych-last,
-  .region-footer-firstcolumn,
-  .region-footer-secondcolumn,
-  .region-footer-thirdcolumn,
-  .region-footer-fourthcolumn {
-    float: right;
-  }
-  .sidebar-first #content {
-    margin-left: 0;
-    margin-right: 25%;
-  }
-  .sidebar-second #content {
-    margin-right: 0;
-    margin-left: 25%;
-  }
-  #sidebar-first {
-    margin-right: -100%;
-  }
-  #sidebar-second {
-    margin-right: -25%;
-  }
-}
diff --git a/core/themes/bartik/css/layout.css b/core/themes/bartik/css/layout.css
index 0278e40..1adacd6 100644
--- a/core/themes/bartik/css/layout.css
+++ b/core/themes/bartik/css/layout.css
@@ -29,6 +29,9 @@ body,
   margin: .5em 5px .75em;
   border: 1px solid #ccc;
 }
+[dir=rtl] .region-header {
+  float: left;
+}
 #secondary-menu {
   width: 100%;
   margin: 0 auto;
@@ -85,6 +88,16 @@ body,
     float: left; /* LTR */
     position: relative;
   }
+  [dir=rtl] #sidebar-first,
+  [dir=rtl] .region-triptych-first,
+  [dir=rtl] .region-triptych-middle,
+  [dir=rtl] .region-triptych-last,
+  [dir=rtl] .region-footer-firstcolumn,
+  [dir=rtl] .region-footer-secondcolumn,
+  [dir=rtl] .region-footer-thirdcolumn,
+  [dir=rtl] .region-footer-fourthcolumn {
+    float: right;
+  }
   #sidebar-first,
   #sidebar-second {
     width: 50%;
@@ -92,6 +105,9 @@ body,
   #sidebar-second {
     margin-left: 50%; /* LTR */
   }
+  [dir=rtl] #sidebar-second {
+    margin-right: 50%;
+  }
   .one-sidebar #sidebar-first,
   .one-sidebar #sidebar-second {
     width: 100%;
@@ -99,6 +115,9 @@ body,
   .one-sidebar #sidebar-second {
     margin-left: 0; /* LTR */
   }
+  [dir=rtl] .one-sidebar #sidebar-second {
+    margin-right: 0;
+  }
   .region-triptych-first,
   .region-triptych-middle,
   .region-triptych-last {
@@ -157,6 +176,18 @@ body,
     float: left; /* LTR */
     position: relative;
   }
+  [dir=rtl] #content,
+  [dir=rtl] #sidebar-first,
+  [dir=rtl] #sidebar-second,
+  [dir=rtl] .region-triptych-first,
+  [dir=rtl] .region-triptych-middle,
+  [dir=rtl] .region-triptych-last,
+  [dir=rtl] .region-footer-firstcolumn,
+  [dir=rtl] .region-footer-secondcolumn,
+  [dir=rtl] .region-footer-thirdcolumn,
+  [dir=rtl] .region-footer-fourthcolumn {
+    float: right;
+  }
   .two-sidebars #content {
     margin-left: 25%;
     margin-right: 25%;
@@ -172,19 +203,33 @@ body,
     margin-left: 25%; /* LTR */
     margin-right: 0; /* LTR */
   }
+  [dir=rtl] .sidebar-first #content {
+    margin-left: 0;
+    margin-right: 25%;
+  }
   .sidebar-second #content {
     margin-right: 25%; /* LTR */
     margin-left: 0; /* LTR */
   }
+  [dir=rtl] .sidebar-second #content {
+    margin-right: 0;
+    margin-left: 25%;
+  }
   #sidebar-first {
     width: 25%;
     margin-left: -100%; /* LTR */
   }
+  [dir=rtl] #sidebar-first {
+    margin-right: -100%;
+  }
   #sidebar-second {
     width: 25%;
     margin-left: -25%; /* LTR */
     clear: none;
   }
+  [dir=rtl] #sidebar-second {
+    margin-right: -25%;
+  }
   .region-triptych-first,
   .region-triptych-middle,
   .region-triptych-last {
diff --git a/core/themes/bartik/css/style.css b/core/themes/bartik/css/style.css
index a7a36a8..0dbc9f7 100644
--- a/core/themes/bartik/css/style.css
+++ b/core/themes/bartik/css/style.css
@@ -149,6 +149,10 @@ blockquote {
   margin: 1.5em 10px;
   padding: 0.5em 10px;
 }
+[dir=rtl] blockquote {
+  border-left: none;
+  border-right: 4px solid #afafaf;
+}
 blockquote:before {
   color: #bbb;
   content: "\201C";
@@ -157,6 +161,9 @@ blockquote:before {
   margin-right: 0.2em;
   vertical-align: -.4em;
 }
+[dir=rtl] blockquote:before {
+  content: "\201D";
+}
 blockquote:after {
   color: #bbb;
   content: "\201D";
@@ -164,6 +171,9 @@ blockquote:after {
   line-height: 0.1em;
   vertical-align: -.45em;
 }
+[dir=rtl] blockquote:after {
+  content: "\201C";
+}
 blockquote > p:first-child {
   display: inline;
 }
@@ -212,6 +222,10 @@ tr th {
   border: 1px solid #fff;
   text-align: left; /* LTR */
 }
+[dir=rtl] tr td,
+[dir=rtl] tr th {
+  text-align: right;
+}
 #footer-wrapper tr td,
 #footer-wrapper tr th {
   border-color: #555;
@@ -242,6 +256,10 @@ table ul.links li {
   margin: 0;
   padding: 0 0 0.25em 1em; /* LTR */
 }
+[dir=rtl] .block ol,
+[dir=rtl] .block ul {
+  padding: 0 1em 0.25em 0;
+}
 .contextual-region .contextual .contextual-links a {
   font-size: 0.923em;
   text-shadow: 0 0 0 !important;
@@ -277,13 +295,23 @@ ul.menu li {
   margin: 1em 0;
   padding: 0 0 0.25em 15px; /* LTR */
 }
+[dir=rtl] .region-content ul,
+[dir=rtl] .region-content ol {
+  padding: 2.5em 0 0.25em 0;
+}
 .item-list ul li {
   margin: 0;
   padding: 0.2em 0.5em 0 0; /* LTR */
 }
+[dir=rtl] .item-list ul li {
+  padding: 0.2em 0 0 0.5em;
+}
 ul.tips {
   padding: 0 0 0 1.25em; /* LTR */
 }
+[dir=rtl] ul.tips {
+  padding: 0 1.25em 0 0;
+}
 
 /* ------------------ Header ------------------ */
 #skip-link {
@@ -316,12 +344,19 @@ ul.tips {
   float: left; /* LTR */
   padding-left: 5px; /* LTR */
 }
+[dir=rtl] #logo {
+  padding: 15px 10px 15px 15px;
+}
 
 #name-and-slogan {
   float: left; /* LTR */
   margin: 0;
   padding: 5px 10px 8px;
 }
+[dir=rtl] #name-and-slogan {
+  margin: 0 15px 30px 0;
+}
+
 #site-name {
   font-size: 1.6em;
   color: #686868;
@@ -374,6 +409,10 @@ h1#site-name {
   margin-right: 2px; /* LTR */
   width: 120px;
 }
+[dir=rtl] .region-header .form-text {
+  margin-left: 2px;
+  margin-right: 0;
+}
 .region-header .form-text:hover,
 .region-header .form-text:focus,
 .region-header .form-text:active {
@@ -443,6 +482,10 @@ h1#site-name {
 .region-header #block-user-login .item-list li.last {
   padding-left: 0.5em; /* LTR */
 }
+[dir=rtl] .region-header #block-user-login .item-list li.last {
+  padding-left: 0;
+  padding-right: 0.5em;
+}
 .region-header #block-user-login .form-actions {
   margin: 4px 0 0;
   padding: 0;
@@ -475,6 +518,14 @@ h1#site-name {
   padding: 0 0.5em;
 }
 
+[dir=rtl] #logo,
+[dir=rtl] #name-and-slogan,
+[dir=rtl] .region-header .block,
+[dir=rtl] .region-header #block-user-login .form-item,
+[dir=rtl] .region-header #block-user-login .item-list li {
+  float: right;
+}
+
 /* --------------- Main Menu ------------ */
 #main-menu {
   clear: both;
@@ -485,6 +536,9 @@ h1#site-name {
   padding: 0;
   text-align: left; /* LTR */
 }
+[dir=rtl] #main-menu-links {
+  text-align: right;
+}
 #main-menu-links li {
   float: none;
   list-style: none;
@@ -504,6 +558,9 @@ h1#site-name {
   margin-bottom: 4px;
   padding: 0.9em 0 0.9em 10px; /* LTR */
 }
+[dir=rtl] #main-menu-links a {
+  padding: 0.9em 10px 0.9em 0;
+}
 #main-menu-links a:hover,
 #main-menu-links a:focus {
   background: #f6f6f2;
@@ -524,6 +581,9 @@ h1#site-name {
   font-size: 0.929em;
   margin: 0 10px;
 }
+[dir=rtl] #secondary-menu-links {
+  float: left;
+}
 #secondary-menu-links  li{
   margin: 0;
   padding: 0;
@@ -633,6 +693,11 @@ h1#page-title {
   float: left; /* LTR */
   margin: 1px 20px 0 0; /* LTR */
 }
+[dir=rtl] .submitted .field-name-field-user-picture img {
+  float: right;
+  margin-left: 20px;
+  margin-right: 0;
+}
 .field-type-taxonomy-term-reference {
   margin: 0 0 1.2em;
 }
@@ -641,6 +706,10 @@ h1#page-title {
   margin: 0;
   padding-right: 5px; /* LTR */
 }
+[dir=rtl] .field-type-taxonomy-term-reference .field-label {
+  padding-left: 5px;
+  padding-right: 0;
+}
 .field-type-taxonomy-term-reference .field-label,
 .field-type-taxonomy-term-reference ul.links {
   font-size: 0.8em;
@@ -659,9 +728,18 @@ h1#page-title {
   padding: 0 1em 0 0; /* LTR */
   white-space: nowrap;
 }
+[dir=rtl] .field-type-taxonomy-term-reference ul.links li {
+  padding: 0 0 0 1em;
+  float: right;
+}
 .link-wrapper {
   text-align: right;
 }
+[dir=rtl] .link-wrapper {
+  text-align: left;
+  margin-right: 236px;
+  margin-left: 0;
+}
 .field-type-image img,
 .field-name-field-user-picture img {
   margin: 0 0 1em;
@@ -687,6 +765,9 @@ ul.links {
 .comment .field-name-field-user-picture img {
   margin-left: 0; /* LTR */
 }
+[dir=rtl] .comment .field-name-field-user-picture img {
+  margin-right: 0;
+}
 .comment {
   margin-bottom: 20px;
   display: table;
@@ -698,6 +779,10 @@ ul.links {
   vertical-align: top;
   overflow: hidden;
 }
+[dir=rtl] .comment .attribution {
+  float: right;
+  padding: 0 0 0 30px;
+}
 .comment .attribution img {
   margin: 0;
   border: 1px solid #d3d7d9;
@@ -731,6 +816,11 @@ ul.links {
   position: absolute;
   width: 20px;
 }
+[dir=rtl] .comment .comment-arrow {
+  background-image: url(../images/comment-arrow-rtl.gif);
+  margin-left: 0;
+  margin-right: -47px;
+}
 .comment .comment-text {
   padding: 10px 25px;
   border: 1px solid #d3d7d9;
@@ -742,16 +832,28 @@ ul.links {
 .comment .indented {
   margin-left: 40px; /* LTR */
 }
+[dir=rtl] .comment .indented {
+  margin-right: 40px;
+  margin-left: 0;
+}
 .comment ul.links {
   padding: 0 0 0.25em 0;
 }
 .comment ul.links li {
   padding: 0 0.5em 0 0; /* LTR */
 }
+[dir=rtl] .comment ul.links li {
+  padding: 0 0 0.5em;
+}
 .comment.unpublished {
   margin-right: 5px; /* LTR */
   padding: 5px 2px 5px 5px; /* LTR */
 }
+[dir=rtl] .comment.unpublished {
+  margin-left: 5px;
+  margin-right: 0;
+  padding: 5px 5px 5px 2px;
+}
 .comment.unpublished .comment-text .comment-arrow {
   border-left: 1px solid #fff4f4;
   border-right: 1px solid #fff4f4;
@@ -908,6 +1010,9 @@ ul.links {
   padding-left: 0; /* LTR */
   margin-left: 0;
 }
+[dir=rtl] #footer-columns .content ul {
+  padding-right: 0;
+}
 #footer-columns .content li {
   list-style: none;
   margin: 0;
@@ -921,6 +1026,9 @@ ul.links {
   padding: 0.8em 2px 0.8em 20px; /* LTR */
   text-indent: -15px;
 }
+[dir=rtl] #footer-columns .content li a {
+  padding: 0.8em 20px 0.8em 2px;
+}
 #footer-columns .content li a:hover,
 #footer-columns .content li a:focus {
   background-color: #1f1f21;
@@ -952,13 +1060,28 @@ ul.links {
   border-right: 1px solid #555; /* LTR */
   border-color: rgba(255, 255, 255, 0.15);
 }
+[dir=rtl] #footer li a {
+  float: right;
+  border-left: 1px solid #555;
+  border-color: rgba(255, 255, 255, 0.15);
+  border-right: none;
+}
 #footer li.first a {
   padding-left: 0; /* LTR */
 }
+[dir=rtl] #footer li.first a {
+  padding-right: 0;
+  padding-left: 12px;
+}
 #footer li.last a {
   padding-right: 0; /* LTR */
   border-right: none; /* LTR */
 }
+[dir=rtl] #footer li.last a {
+  padding-left: 0;
+  padding-right: 12px;
+  border-left: none;
+}
 #footer-wrapper tr.odd {
   background-color: transparent;
 }
@@ -990,6 +1113,11 @@ div.tabs {
   vertical-align: bottom;
   margin: 0 5px 0 0; /* LTR */
 }
+[dir=rtl] .tabs ul.primary li {
+  margin: 0 0 0 5px;
+  float: right;
+  zoom: 1;
+}
 .tabs ul.primary li.active a {
   border-bottom: 1px solid #ffffff;
 }
@@ -1027,12 +1155,23 @@ div.tabs {
   margin: 0;
   padding: 0 1em;
 }
+[dir=rtl] .tabs ul.secondary li {
+  border-left: 1px solid #ccc;
+  border-right: none;
+  float: right;
+}
 .tabs ul.secondary li:last-child {
   border-right: none; /* LTR */
 }
+[dir=rtl] .tabs ul.secondary li:last-child {
+  border-left: none;
+}
 .tabs ul.secondary li:first-child {
   padding-left: 0; /* LTR */
 }
+[dir=rtl] .tabs ul.secondary li:first-child {
+  padding-right: 0;
+}
 .tabs ul.secondary li a {
   display: inline;
   padding: 0.25em 0.5em;
@@ -1072,6 +1211,14 @@ div.messages {
 
 /* -------------- Password Meter  ------------- */
 
+[dir=rtl] #password-strength {
+  left: auto;
+  margin-top: 2em;
+  right: 16em;
+}
+[dir=rtl] .form-item-pass-pass2 label {
+  clear: right;
+}
 .confirm-parent,
 .password-parent {
   width: 34em;
@@ -1088,6 +1235,10 @@ div.password-confirm {
 .password-strength-text {
   margin-top: 0.2em;
 }
+[dir=rtl] #password-strength-text {
+  margin-top: 0;
+  float: left;
+}
 div.password-confirm {
   margin-top: 2.2em;
   width: 20.73em;
@@ -1119,6 +1270,14 @@ div.password-confirm {
 
 /* -------------- Form Elements   ------------- */
 
+[dir=rtl] #user-profile-form input#edit-submit {
+  margin-left: 0;
+}
+[dir=rtl] .password-suggestions ul li {
+  margin-right: 1.2em;
+  margin-left: 0;
+}
+
 details,
 fieldset,
 .filter-wrapper {
@@ -1254,9 +1413,15 @@ input.form-submit:focus {
 .js input.form-autocomplete {
   background-position: 100% 4px; /* LTR */
 }
+.js[dir=rtl] input.form-autocomplete {
+  background-position: 1% 4px;
+}
 .js input.throbbing {
   background-position: 100% -16px; /* LTR */
 }
+.js[dir=rtl] input.throbbing {
+  background-position: 1% -16px;
+}
 
 /* Comment form */
 .comment-form label {
@@ -1264,6 +1429,9 @@ input.form-submit:focus {
   font-size: 0.929em;
   width: 120px;
 }
+[dir=rtl] .comment-form label {
+  float: right;
+}
 .comment-form input,
 .comment-form .form-select {
   margin: 0;
@@ -1283,6 +1451,12 @@ input.form-submit:focus {
 .comment-form .form-radios {
   margin-left: 120px; /* LTR */
 }
+[dir=rtl] .comment-form .form-type-checkbox,
+[dir=rtl] .comment-form .form-radios,
+[dir=rtl] .comment-form .form-item .description {
+  margin-left: 0;
+  margin-right: 120px;
+}
 .comment-form .form-type-checkbox label,
 .comment-form .form-radios label {
   float: none;
@@ -1333,6 +1507,10 @@ input.form-submit:focus {
 #edit-actions input {
   margin-right: 0.6em; /* LTR */
 }
+[dir=rtl] #edit-actions input {
+  margin-left: 0.6em;
+  margin-right: 0;
+}
 
 /* -------------- Other Overrides ------------- */
 
@@ -1350,6 +1528,20 @@ div.password-suggestions {
   font-size: 1em;
 }
 
+/* ---------- Color Form ----------- */
+
+[dir=rtl] .color-form #palette {
+  margin-left: 0;
+  margin-right: 20px;
+}
+[dir=rtl] .color-form .form-item label {
+  float: right;
+}
+[dir=rtl] .color-form #palette .lock {
+  right: -20px;
+  left: 0;
+}
+
 /* --------------- Search Form ---------------- */
 
 #block-search-form {
@@ -1375,6 +1567,12 @@ div.password-suggestions {
   margin-right: 5px;
   width: 9em;
 }
+[dir=rtl] #search-form input#edit-keys,
+[dir=rtl] #block-search-form .form-item-search-block-form input {
+  float: right;
+  margin-left: 5px;
+  margin-right: 0;
+}
 #search-block-form input.form-submit,
 #search-form input.form-submit {
   margin-left: 0;
@@ -1426,6 +1624,9 @@ ol.search-results {
   float: left; /* LTR */
   margin: 0;
 }
+[dir=rtl] .shortcut-wrapper h1#page-title {
+  float: right;
+}
 div.add-or-remove-shortcuts {
   padding-top: 0.9em;
 }
@@ -1554,6 +1755,9 @@ div.admin-panel .description {
   #logo {
     padding: 5px 0 0 5px; /* LTR */
   }
+  [dir=rtl] #logo {
+    padding: 5px 5px 0 0;
+  }
   #name-and-slogan {
     padding: 10px 10px 8px;
   }
@@ -1569,9 +1773,18 @@ div.admin-panel .description {
     display: inline-block;
     width: 32.75%;
   }
+  [dir=rtl] #main-menu-links li {
+    float: right;
+    margin-left: 5px;
+    margin-right: 0;
+  }
   #main-menu-links li:nth-child(3n) {
     margin-right: -5px; /* LTR */
   }
+  [dir=rtl] #main-menu-links li:nth-child(3n) {
+    margin-left: -5px;
+    margin-right: 0;
+  }
   #main-menu-links a {
     float: none;
     display: block;
@@ -1589,10 +1802,16 @@ div.admin-panel .description {
   #logo {
     padding: 15px 15px 15px 10px; /* LTR */
   }
+  [dir=rtl] #logo {
+    padding: 15px 10px 15px 15px;
+  }
   #name-and-slogan {
     padding: 26px 0 0;
     margin: 0 0 30px 15px; /* LTR */
   }
+  [dir=rtl] #name-and-slogan {
+    margin: 0 15px 30px 0;
+  }
   #site-name {
     font-size: 1.821em;
   }
@@ -1608,6 +1827,9 @@ div.admin-panel .description {
     margin: 0 1px;
     width: auto;
   }
+  [dir=rtl] #main-menu-links li {
+    float: right;
+  }
   #main-menu-links a {
     float: left; /* LTR */
     padding: 0.7em 0.8em;
@@ -1615,6 +1837,10 @@ div.admin-panel .description {
     border-bottom-left-radius: 0;
     border-bottom-right-radius: 0;
   }
+  [dir=rtl] #main-menu-links a {
+    float: right;
+    padding: 0.7em 0.8em;
+  }
   .featured #main-menu-links li a:active,
   .featured #main-menu-links li a.active {
     background: #f0f0f0;
@@ -1669,6 +1895,11 @@ div.admin-panel .description {
   padding-left: 0; /* LTR */
 }
 
+[dir=rtl] .views-display-top .secondary .action-list {
+  padding-left: inherit;
+  padding-right: 0;
+}
+
 /* @end */
 
 /* @group Attachment details tabs
@@ -1754,6 +1985,9 @@ div.admin-panel .description {
 .views-display-columns details summary {
   padding: 0 0 4px 2px; /* LTR */
 }
+[dir=rtl] .views-display-columns details summary {
+  padding: 0 2px 4px 0;
+}
 
 .views-display-columns a.fieldset-title {
   color: #0071B3;
diff --git a/core/themes/seven/style-rtl.css b/core/themes/seven/style-rtl.css
deleted file mode 100644
index 70770d1..0000000
--- a/core/themes/seven/style-rtl.css
+++ /dev/null
@@ -1,219 +0,0 @@
-/**
- * Generic elements.
- */
-dl dd,
-dl dl {
-  margin-right: 20px;
-}
-ul,
-.block ul,
-.item-list ul {
-  margin: 0.25em 1.5em 0.25em 0;
-}
-ol {
-  margin: 0.25em 2em 0.25em 0;
-}
-
-/**
- * Skip link.
- */
-#skip-link {
-  right: 50%;
-  margin-right: -5.25em;
-}
-#skip-link a,
-#skip-link a:link,
-#skip-link a:visited {
-  padding: 1px 10px 2px 10px;
-}
-
-/**
- * Branding.
- */
-#branding {
-  padding: 20px 20px 0 20px;
-}
-
-/**
- * Help.
- */
-#help div.more-help-link {
-  text-align: left;
-}
-
-/**
- * Page title.
- */
-#branding h1.page-title {
-  float: right;
-}
-
-/**
- * Tabs.
- */
-ul.primary li,
-ul.primary li a:link,
-ul.primary li a.active {
-  float: right;
-}
-ul.primary,
-ul.secondary {
-  float: left;
-}
-ul.secondary li {
- float: none;
-}
-ul.primary {
- padding-top: 0;
-}
-
-/**
- * Page layout.
- */
-ul.links li,
-ul.inline li {
-  padding-left: 1em;
-  padding-right: 0;
-}
-.admin-list li a {
-  background: url(images/list-item-rtl.png) no-repeat right 11px;
-  padding: 9px 39px 9px 9px;
-}
-
-/**
- * Tables.
- */
-table th.active a {
-  padding: 0 0 0 25px;
-}
-table th.active img {
-  left: 3px;
-  right: auto;
-}
-/**
- * Exception for webkit bug with the right border of the last cell
- * in some tables, since it's webkit only, we can use :last-child
- */
-tr td:last-child {
-  border-left: 1px solid #bebfb9;
-  border-right: none;
-}
-
-/* Filter */
-ul.tips li {
-  margin: 0.25em 1.5em 0.25em 0;
-}
-body div.form-type-radio div.description,
-body div.form-type-checkbox div.description {
-  margin-left: 0;
-  margin-right: 1.5em;
-}
-
-/* Update options. */
-div.admin-options label,
-div.admin-options div.form-item {
-  margin-left: 10px;
-  margin-right: 0;
-  float: right;
-}
-
-/* Maintenance theming */
-body.in-maintenance #sidebar-first {
-  float: right;
-}
-body.in-maintenance #content {
-  float: left;
-  padding-left: 20px;
-  padding-right: 0;
-}
-ol.task-list {
-  margin-right: 0;
-}
-ol.task-list li {
-  padding: 0.5em 20px 0.5em 1em;
-}
-ol.task-list li.active {
-  background: transparent url(images/task-item-rtl.png) no-repeat right 50%;
-  padding: 0.5em 20px 0.5em 1em;
-}
-
-/* Overlay theming */
-.overlay #branding .breadcrumb {
-  float: right;
-}
-.overlay ul.secondary {
-  margin: -1.4em 0 0.3em 0;
-}
-
-/* Recent content block */
-#block-node-recent .more-link {
-  padding: 0 0 5px 5px;
-}
-
-/**
- * Improve spacing of cancel link.
- */
-#edit-cancel {
-  margin-right: 10px;
-}
-
-/**
- * Views styling
- */
- /* @group Forms */
-
-.views-admin .form-submit,
-.views-admin a.button {
-  margin-left: 0;
-}
-
-/* @end */
-
-/* @group Lists */
-
-.views-admin .links li {
-  padding-left: 0;
-}
-
-/* @end */
-
-/* @group Attachments */
-
-.views-displays .secondary {
-  text-align: right;
-}
-
-/* @end */
-
-/* @group Attachment details tabs */
-
-.views-display-top ul.secondary {
-  float: right;
-}
-
-.views-displays .secondary .action-list  li:first-child {
-  -moz-border-radius: 7px 0 0 0;
-  -webkit-border-radius: 7px 0 0 0;
-  border-radius: 7px 0 0 0;
-}
-
-/* @end */
-
-
-/**
- * Node Add/Edit Page Layout
- */
-
-/* Narrow screens */
-/*.overlay .layout-region-secondary {
-     -moz-box-shadow: inset -0.15em 0.3em .5em rgba(0, 0, 0, .1);
-  -webkit-box-shadow: inset -0.15em 0.3em .5em rgba(0, 0, 0, .1);
-          box-shadow: inset -0.15em 0.3em .5em rgba(0, 0, 0, .1);
-}*/
-/* Wide screens */
-@media only screen and (min-width: 780px) {
-  .overlay [id="edit-additional-settings"] {
-    -webkit-box-shadow: inset -3px 3px 5px rgba(0, 0, 0, .15);
-    box-shadow:         inset -3px 3px 5px rgba(0, 0, 0, .15);
-  }
-}
diff --git a/core/themes/seven/style.css b/core/themes/seven/style.css
index 052d0f1..319f1ed 100644
--- a/core/themes/seven/style.css
+++ b/core/themes/seven/style.css
@@ -63,6 +63,10 @@ dl dl {
   margin-left: 20px; /* LTR */
   margin-bottom: 10px;
 }
+[dir=rtl] dl dd,
+[dir=rtl] dl dl {
+  margin-right: 20px;
+}
 blockquote {
   margin: 1em 40px;
 }
@@ -107,6 +111,11 @@ ul,
   list-style-image: none;
   margin: 0.25em 0 0.25em 1.5em; /* LTR */
 }
+[dir=rtl] ul,
+[dir=rtl] .block ul,
+[dir=rtl] .item-list ul {
+  margin: 0.25em 1.5em 0.25em 0;
+}
 .item-list .pager li {
   padding: 0.5em;
 }
@@ -123,6 +132,9 @@ ol {
   list-style-type: decimal;
   margin: 0.25em 0 0.25em 2em; /* LTR */
 }
+[dir=rtl] ol {
+  margin: 0.25em 2em 0.25em 0;
+}
 .item-list ul li.collapsed,
 ul.menu li.collapsed {
   list-style-image:url(../../misc/menu-collapsed.png);
@@ -158,6 +170,10 @@ pre {
   width: auto;
   z-index: 50;
 }
+[dir=rtl] #skip-link {
+  right: 50%;
+  margin-right: -5.25em;
+}
 #skip-link a,
 #skip-link a:link,
 #skip-link a:visited {
@@ -169,6 +185,11 @@ pre {
   text-decoration: none;
   border-radius: 0 0 10px 10px;
 }
+[dir=rtl] #skip-link a,
+[dir=rtl] #skip-link a:link,
+[dir=rtl] #skip-link a:visited {
+  padding: 1px 10px 2px 10px;
+}
 #skip-link a:hover,
 #skip-link a:focus,
 #skip-link a:active {
@@ -184,6 +205,9 @@ pre {
   position: relative;
   background-color: #e0e0d8;
 }
+[dir=rtl] #branding {
+  padding: 20px 20px 0 20px;
+}
 .breadcrumb {
   font-size: 0.846em;
   line-height: 1em;
@@ -202,6 +226,9 @@ pre {
 #help div.more-help-link {
   text-align: right; /* LTR */
 }
+[dir=rtl] #help div.more-help-link {
+  text-align: left;
+}
 
 /**
  * Page title.
@@ -218,6 +245,9 @@ pre {
   font-weight: normal;
   float: left; /* LTR */
 }
+[dir=rtl] #branding h1.page-title {
+  float: right;
+}
 
 /**
  * Console.
@@ -260,6 +290,11 @@ ul.primary li.active a {
   border-color: #a6a7a2;
   border-radius: 8px 8px 0 0;
 }
+[dir=rtl] ul.primary li,
+[dir=rtl] ul.primary li a:link,
+[dir=rtl] ul.primary li a.active {
+  float: right;
+}
 ul.primary li.active a,
 ul.primary li.active a.active,
 ul.primary li.active a:active,
@@ -306,6 +341,10 @@ ul.secondary li.active a.active {
   color: #fff;
   background: #666;
 }
+[dir=rtl] ul.primary,
+[dir=rtl] ul.secondary {
+  float: left;
+}
 #content {
   clear: left;
 }
@@ -383,6 +422,11 @@ ul.links li,
 ul.inline li {
   padding-right: 1em; /* LTR */
 }
+[dir=rtl] ul.links li,
+[dir=rtl] ul.inline li {
+  padding-left: 1em;
+  padding-right: 0;
+}
 ul.inline li {
   display: inline;
 }
@@ -407,6 +451,10 @@ ul.inline li {
   padding: 9px 9px 9px 39px; /* LTR */
   min-height: 0;
 }
+[dir=rtl] .admin-list li a {
+  background: url(images/list-item-rtl.png) no-repeat right 11px;
+  padding: 9px 39px 9px 9px;
+}
 .admin-list.compact li a {
   background-image:  none;
   padding: 2px 19px;
@@ -477,11 +525,27 @@ table th a {
 table th.active a {
   padding: 0 25px 0 0; /* LTR */
 }
+[dir=rtl] table th.active a {
+  padding: 0 0 0 25px;
+}
 table th.active img {
   position: absolute;
   top: 3px;
   right: 3px; /* LTR */
 }
+[dir=rtl] table th.active img {
+  left: 3px;
+  right: auto;
+}
+/**
+ * Exception for webkit bug with the right border of the last cell
+ * in some tables, since it's webkit only, we can use :last-child
+ */
+[dir=rtl] tr td:last-child {
+  border-left: 1px solid #bebfb9;
+  border-right: none;
+}
+
 /**
  * Force browsers to calculate the width of a 'select all' TH element.
  */
@@ -600,10 +664,18 @@ div.description,
 ul.tips li {
   margin: 0.25em 0 0.25em 1.5em; /* LTR */
 }
+[dir=rtl] ul.tips li {
+  margin: 0.25em 1.5em 0.25em 0;
+}
 body div.form-type-radio div.description,
 body div.form-type-checkbox div.description {
   margin-left: 1.5em; /* LTR */
 }
+[dir=rtl] body div.form-type-radio div.description,
+[dir=rtl] body div.form-type-checkbox div.description {
+  margin-left: 0;
+  margin-right: 1.5em;
+}
 .button {
   cursor: pointer;
   padding: 4px 17px;
@@ -757,6 +829,9 @@ select.form-select:focus {
 #edit-cancel {
   margin-left: 10px; /* LTR */
 }
+[dir=rtl] #edit-cancel {
+  margin-right: 10px;
+}
 
 /**
  * Improve form element usability on narrow devices.
@@ -899,6 +974,12 @@ div.admin-options div.form-item {
   margin-right: 10px; /* LTR */
   float: left; /* LTR */
 }
+[dir=rtl] div.admin-options label,
+[dir=rtl] div.admin-options div.form-item {
+  margin-left: 10px;
+  margin-right: 0;
+  float: right;
+}
 div.admin-options div.form-item {
   padding: 0;
   border: 0;
@@ -915,12 +996,20 @@ body.in-maintenance #sidebar-first {
   max-width: 200px;
   width: 25%;
 }
+[dir=rtl] body.in-maintenance #sidebar-first {
+  float: right;
+}
 body.in-maintenance #content {
   float: right; /* LTR */
   max-width: 550px;
   clear: none;
   width: 72%;
 }
+[dir=rtl] body.in-maintenance #content {
+  float: left;
+  padding-left: 20px;
+  padding-right: 0;
+}
 body.in-maintenance #page {
   max-width: 770px;
   margin: 0 auto;
@@ -961,15 +1050,25 @@ ol.task-list {
   list-style-type: none;
   list-style-image: none;
 }
+[dir=rtl] ol.task-list {
+  margin-right: 0;
+}
 ol.task-list li {
   padding: 0.5em 1em 0.5em 20px; /* LTR */
   color: #adadad;
 }
+[dir=rtl] ol.task-list li {
+  padding: 0.5em 20px 0.5em 1em;
+}
 ol.task-list li.active {
   background: transparent url(images/task-item.png) no-repeat 3px 50%; /* LTR */
   padding: 0.5em 1em 0.5em 20px; /* LTR */
   color: #000;
 }
+[dir=rtl] ol.task-list li.active {
+  background: transparent url(images/task-item-rtl.png) no-repeat right 50%;
+  padding: 0.5em 20px 0.5em 1em;
+}
 ol.task-list li.done {
   background: transparent url(images/task-check.png) no-repeat 0 50%;
   color: green;
@@ -1012,6 +1111,9 @@ body.in-maintenance #branding .step-indicator {
   position: relative;
   z-index: 10;
 }
+[dir=rtl] .overlay #branding .breadcrumb {
+  float: right;
+}
 #overlay-tabs {
   bottom: -1px;
   font-size: 1.54em;
@@ -1023,6 +1125,9 @@ body.in-maintenance #branding .step-indicator {
   margin: -1.4em 0 0.3em 0; /* LTR */
   overflow: visible;
 }
+[dir=rtl] .overlay ul.secondary {
+  margin: -1.4em 0 0.3em 0;
+}
 .overlay #content {
   padding: 0;
 }
@@ -1104,6 +1209,9 @@ h1#overlay-title {
 #block-node-recent .more-link {
   padding: 0 5px 5px 0; /* LTR */
 }
+[dir=rtl] #block-node-recent .more-link {
+  padding: 0 0 5px 5px;
+}
 
 /* Dropbutton */
 .js .dropbutton-widget {
@@ -1213,6 +1321,12 @@ details.fieldset-no-legend {
   margin-right: 0; /* LTR */
   margin-top: 0;
 }
+[dir=rtl] .views-admin input.form-submit,
+[dir=rtl] .views-ui-dialog input.form-submit,
+[dir=rtl] .views-admin a.button,
+[dir=rtl] .views-ui-dialog a.button{
+  margin-left: 0;
+}
 
 /* Override for a button on the edit display screen */
 #edit-displays-preview-controls .form-submit {
@@ -1263,6 +1377,10 @@ details.fieldset-no-legend {
   padding: 0;
 }
 
+[dir=rtl] .views-displays ul.secondary {
+  text-align: right;
+}
+
 .views-displays ul.secondary li a,
 .views-displays ul.secondary li.active a,
 .views-displays ul.secondary li.active a.active {
@@ -1281,6 +1399,9 @@ details.fieldset-no-legend {
 .views-admin .links li {
   padding-right: 0; /* LTR */
 }
+[dir=rtl] .views-admin .links li {
+  padding-left: 0;
+}
 
 .views-admin .button .links li {
   padding-right: 12px; /* LTR */
@@ -1290,11 +1411,19 @@ details.fieldset-no-legend {
   background-color: transparent;
   float: left
 }
+[dir=rtl] .views-display-top ul.secondary {
+  float: right;
+}
 
 .views-display-top .secondary .action-list li {
   float: none;
   margin: 0;
 }
+[dir=rtl] .views-displays .secondary .action-list  li:first-child {
+  -moz-border-radius: 7px 0 0 0;
+  -webkit-border-radius: 7px 0 0 0;
+  border-radius: 7px 0 0 0;
+}
 
 /* @end */
 
@@ -1652,6 +1781,10 @@ details.fieldset-no-legend {
   .overlay .layout-region-node-footer {
     padding-bottom: 1.5em;
   }
+  [dir=rtl] .overlay [id="edit-additional-settings"] {
+    -webkit-box-shadow: inset -3px 3px 5px rgba(0, 0, 0, .15);
+    box-shadow:         inset -3px 3px 5px rgba(0, 0, 0, .15);
+  }
 }
 @media
   screen and (max-width: 1020px),
@@ -1672,7 +1805,6 @@ details.fieldset-no-legend {
   }
 }
 
-
 /**
  * Node form dropbuttons.
  */
diff --git a/core/themes/seven/vertical-tabs-rtl.css b/core/themes/seven/vertical-tabs-rtl.css
deleted file mode 100644
index 9181ee9..0000000
--- a/core/themes/seven/vertical-tabs-rtl.css
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * Override of misc/vertical-tabs-rtl.css.
- */
-.vertical-tabs-list {
-  float: right;
-  margin: 0 0 -1px -100%;
-}
-.vertical-tab-button.selected {
-  border-left: 1px solid #fcfcfa;
-}
-.vertical-tabs-panes {
-  margin: 0 240px 0 0;
-  border-right: 1px solid #a6a5a1;
-}
diff --git a/core/themes/seven/vertical-tabs.css b/core/themes/seven/vertical-tabs.css
index 90f85fa..409fd5c 100644
--- a/core/themes/seven/vertical-tabs.css
+++ b/core/themes/seven/vertical-tabs.css
@@ -17,6 +17,10 @@
   border-bottom: 1px solid #ccc;
   line-height: 1;
 }
+[dir=rtl] .vertical-tabs-list {
+  float: right;
+  margin: 0 0 -1px -100%;
+}
 .vertical-tab-button {
   position: relative;
   margin: 0;
@@ -30,6 +34,9 @@
   border-right: 1px solid #fcfcfa; /* LTR */
   box-shadow: 0 5px 5px -5px hsla(0, 0%, 0%, 0.3);
 }
+[dir=rtl] .vertical-tab-button.selected {
+  border-left: 1px solid #fcfcfa;
+}
 .vertical-tab-button:focus,
 .vertical-tab-button:active {
   z-index: 2;
@@ -66,6 +73,10 @@
   border-left: 1px solid #a6a5a1; /* LTR */
   background-color: #fcfcfa;
 }
+[dir=rtl] .vertical-tabs-panes {
+  margin: 0 240px 0 0;
+  border-right: 1px solid #a6a5a1;
+}
 .vertical-tabs-panes:after {
   content: "";
   display: table;
diff --git a/core/themes/stark/css/layout-rtl.css b/core/themes/stark/css/layout-rtl.css
deleted file mode 100644
index d5e9c6d..0000000
--- a/core/themes/stark/css/layout-rtl.css
+++ /dev/null
@@ -1,52 +0,0 @@
-@media all and (min-width: 480px) and (max-width: 959px) {
-  body.sidebar-first #content,
-  body.two-sidebars #content {
-    float: left;
-  }
-  body.sidebar-second #content {
-    float: right;
-  }
-
-  #sidebar-first {
-    float: right;
-  }
-
-  #sidebar-second {
-    float: left;
-  }
-  body.two-sidebars #sidebar-second {
-    float: right;
-    clear: right;
-  }
-  body.two-sidebars #sidebar-second .block {
-    float: right;
-  }
-}
-
-@media all and (min-width: 960px) {
-  #content {
-    float: right;
-  }
-  body.sidebar-first #content {
-    left: 0;
-    right: 20%;
-  }
-  body.two-sidebars #content {
-    left: 0;
-    right: 20%;
-  }
-
-  #sidebar-first {
-    float: right;
-    left: 0;
-    right: -80%;
-  }
-  body.two-sidebars #sidebar-first {
-    left: 0;
-    right: -60%;
-  }
-
-  #sidebar-second {
-    float: left;
-  }
-}
diff --git a/core/themes/stark/css/layout.css b/core/themes/stark/css/layout.css
index 39f533b..9c1ad2f 100644
--- a/core/themes/stark/css/layout.css
+++ b/core/themes/stark/css/layout.css
@@ -33,29 +33,49 @@ img {
     width: 67%;
     float: right; /* LTR */
   }
+  [dir=rtl] body.sidebar-first #content,
+  [dir=rtl] body.two-sidebars #content {
+    float: left;
+  }
   body.sidebar-second #content {
     width: 67%;
     float: left; /* LTR */
   }
+  [dir=rtl] body.sidebar-second #content {
+    float: right;
+  }
 
   #sidebar-first {
     width: 33%;
     float: left; /* LTR */
   }
+  [dir=rtl] #sidebar-first {
+    float: right;
+  }
 
   #sidebar-second {
     width: 33%;
     float: right; /* LTR */
   }
+  [dir=rtl] #sidebar-second {
+    float: left;
+  }
   body.two-sidebars #sidebar-second {
     clear: both;
     width: 100%;
   }
+  [dir=rtl] body.two-sidebars #sidebar-second {
+    float: right;
+    clear: right;
+  }
 
   body.two-sidebars #sidebar-second .block {
     float: left; /* LTR */
     width: 33%;
   }
+  [dir=rtl] body.two-sidebars #sidebar-second .block {
+    float: right;
+  }
   body.two-sidebars #sidebar-second .block:nth-child(3n+1) {
     clear: both;
   }
@@ -66,10 +86,17 @@ img {
     width: 100%;
     float: left; /* LTR */
   }
+  [dir=rtl] #content {
+    float: right;
+  }
   body.sidebar-first #content {
     width: 80%;
     left: 20%; /* LTR */
   }
+  [dir=rtl] body.sidebar-first #content {
+    left: 0;
+    right: 20%;
+  }
   body.sidebar-second #content {
     width: 80%;
   }
@@ -77,20 +104,36 @@ img {
     width: 60%;
     left: 20%; /* LTR */
   }
+  [dir=rtl] body.two-sidebars #content {
+    left: 0;
+    right: 20%;
+  }
 
   #sidebar-first {
     width: 20%;
     float: left; /* LTR */
     left: -80%; /* LTR */
   }
+  [dir=rtl] #sidebar-first {
+    float: right;
+    left: 0;
+    right: -80%;
+  }
   body.two-sidebars #sidebar-first {
     left: -60%; /* LTR */
   }
+  [dir=rtl] body.two-sidebars #sidebar-first {
+    left: 0;
+    right: -60%;
+  }
 
   #sidebar-second {
     float: right; /* LTR */
     width: 20%;
   }
+  [dir=rtl] #sidebar-second {
+    float: left;
+  }
 }
 
 /**