diff --git a/core/MAINTAINERS.txt b/core/MAINTAINERS.txt
index d04d2c5d64192d35345b96d69bd3a0bc007e16fa..53923546b8d4d01822030e435f6fe0482c771d7a 100644
--- a/core/MAINTAINERS.txt
+++ b/core/MAINTAINERS.txt
@@ -257,6 +257,11 @@ Language
 - Francesco Placella 'plach' https://www.drupal.org/u/plach
 - Daniel F. Kudwien 'sun' https://www.drupal.org/u/sun
 
+Layout Builder
+- Ted Bowman 'tedbow' https://www.drupal.org/u/tedbow
+- Emilie Nouveau 'DyanneNova' https://www.drupal.org/u/dyannenova
+- Tim Plunkett 'tim.plunkett' https://www.drupal.org/u/tim.plunkett
+
 Link Field
 - Weber Macedo 'Mac_Weber' https://www.drupal.org/u/mac_weber
 
diff --git a/core/modules/layout_builder/css/layout-builder-content-translation.css b/core/modules/layout_builder/css/layout-builder-content-translation.css
deleted file mode 100644
index bff9c47067d9259f7439b83958339a1cc6077748..0000000000000000000000000000000000000000
--- a/core/modules/layout_builder/css/layout-builder-content-translation.css
+++ /dev/null
@@ -1,5 +0,0 @@
-/* @todo Move this to Seven as part of https://www.drupal.org/node/3041053 */
-.layout-builder-translation-warning {
-  background: left 2px url(../../../misc/icons/e29700/warning.svg) no-repeat;
-  padding-left: 20px;
-}
diff --git a/core/modules/layout_builder/css/layout-builder.css b/core/modules/layout_builder/css/layout-builder.css
index c0eb0da122e83f8aaeb19129a21b04b4c3580502..b7ccc1abad4760acaa83235574b1714938f1ad68 100644
--- a/core/modules/layout_builder/css/layout-builder.css
+++ b/core/modules/layout_builder/css/layout-builder.css
@@ -88,10 +88,10 @@
   background-repeat: no-repeat;
 }
 .layout-builder__message--defaults .messages {
-  background-image: url('../images/globe.svg');
+  background-image: url("../images/globe.svg");
 }
 .layout-builder__message--overrides .messages {
-  background-image: url('../images/location.svg');
+  background-image: url("../images/location.svg");
 }
 
 /**
@@ -193,11 +193,11 @@
   display: none;
 }
 
-.layout-builder--move-blocks-active  .layout-builder__region-label {
+.layout-builder--move-blocks-active .layout-builder__region-label {
   display: block;
 }
 
-.layout-builder--move-blocks-active  .layout-builder__section-label {
+.layout-builder--move-blocks-active .layout-builder__section-label {
   display: inline;
 }
 
diff --git a/core/modules/layout_builder/layout_builder.info.yml b/core/modules/layout_builder/layout_builder.info.yml
index d3d9699c670b062665b1f689abdb434c4da9be04..6e700e1b09bd00cbf845a14fbfef9c4a7ac83596 100644
--- a/core/modules/layout_builder/layout_builder.info.yml
+++ b/core/modules/layout_builder/layout_builder.info.yml
@@ -1,7 +1,7 @@
 name: 'Layout Builder'
 type: module
 description: 'Allows users to add and arrange blocks and content fields directly on the content.'
-package: Core (Experimental)
+package: Core
 version: VERSION
 core: 8.x
 dependencies:
diff --git a/core/modules/layout_builder/layout_builder.libraries.yml b/core/modules/layout_builder/layout_builder.libraries.yml
index 57b65605ca1111e8af45a55bdaeaa6639a701cc9..d77b6213685a466015d67962563b4a490c527f7c 100644
--- a/core/modules/layout_builder/layout_builder.libraries.yml
+++ b/core/modules/layout_builder/layout_builder.libraries.yml
@@ -27,9 +27,3 @@ fourcol_section:
   css:
     theme:
       layouts/fourcol_section/fourcol_section.css: {}
-
-drupal.layout_builder_content_translation_admin:
-  version: VERSION
-  css:
-    theme:
-      css/layout-builder-content-translation.css: {}
diff --git a/core/modules/layout_builder/layout_builder.module b/core/modules/layout_builder/layout_builder.module
index b20ddfb126da2f56ce5e7b04a74407c16b24e144..f03e73afd0956eb5e1e949f1f845cf4593633b7a 100644
--- a/core/modules/layout_builder/layout_builder.module
+++ b/core/modules/layout_builder/layout_builder.module
@@ -400,11 +400,6 @@ function layout_builder_preprocess_language_content_settings_table(&$variables)
           '#attributes' => [
             'class' => ['layout-builder-translation-warning'],
           ],
-          '#attached' => [
-            'library' => [
-              'layout_builder/drupal.layout_builder_content_translation_admin',
-            ],
-          ],
         ],
       ];
     }
diff --git a/core/modules/layout_builder/src/Access/LayoutBuilderAccessCheck.php b/core/modules/layout_builder/src/Access/LayoutBuilderAccessCheck.php
index 30795008d3972fb9162d500adb2d58c4df23e479..671265499a7866804430f27f31d0d8c43b615a47 100644
--- a/core/modules/layout_builder/src/Access/LayoutBuilderAccessCheck.php
+++ b/core/modules/layout_builder/src/Access/LayoutBuilderAccessCheck.php
@@ -15,6 +15,7 @@
  * @ingroup layout_builder_access
  *
  * @internal
+ *   Tagged services are internal.
  */
 class LayoutBuilderAccessCheck implements AccessInterface {
 
diff --git a/core/modules/layout_builder/src/Access/LayoutPreviewAccessAllowed.php b/core/modules/layout_builder/src/Access/LayoutPreviewAccessAllowed.php
index 6754e2be41b38ee63dcd7ba6d57cea5370190249..f5e4b41d0a590d077f49b0964e0b38bf907f7c20 100644
--- a/core/modules/layout_builder/src/Access/LayoutPreviewAccessAllowed.php
+++ b/core/modules/layout_builder/src/Access/LayoutPreviewAccessAllowed.php
@@ -10,6 +10,7 @@
  * Accessible class to allow access for inline blocks in the Layout Builder.
  *
  * @internal
+ *   Tagged services are internal.
  */
 class LayoutPreviewAccessAllowed implements AccessibleInterface {
 
diff --git a/core/modules/layout_builder/src/Access/LayoutSectionAccessCheck.php b/core/modules/layout_builder/src/Access/LayoutSectionAccessCheck.php
index 6abff2a4bf694ea5086073c79fffa2df7529f66d..e57218c9d94944176155ac5db63f02dfc355c248 100644
--- a/core/modules/layout_builder/src/Access/LayoutSectionAccessCheck.php
+++ b/core/modules/layout_builder/src/Access/LayoutSectionAccessCheck.php
@@ -12,6 +12,7 @@
  * Provides an access check for the Layout Builder UI.
  *
  * @internal
+ *   Tagged services are internal.
  *
  * @todo Deprecated in Drupal 8.7.0 and will be removed before Drupal 9.0.0. Use
  *   \Drupal\layout_builder\Access\LayoutBuilderAccessCheck instead. See
diff --git a/core/modules/layout_builder/src/Cache/LayoutBuilderIsActiveCacheContext.php b/core/modules/layout_builder/src/Cache/LayoutBuilderIsActiveCacheContext.php
index 3c3bc25c400585e5ee2d09365fdb7dae69c7dd6e..5edec7f0e5dc24dcdf52fc50425eb6825322189d 100644
--- a/core/modules/layout_builder/src/Cache/LayoutBuilderIsActiveCacheContext.php
+++ b/core/modules/layout_builder/src/Cache/LayoutBuilderIsActiveCacheContext.php
@@ -13,6 +13,9 @@
  * Cache context ID: 'layout_builder_is_active:%entity_type_id', e.g.
  * 'layout_builder_is_active:node' (to vary by whether the Node entity type has
  * Layout Builder enabled).
+ *
+ * @internal
+ *   Tagged services are internal.
  */
 class LayoutBuilderIsActiveCacheContext implements CalculatedCacheContextInterface {
 
diff --git a/core/modules/layout_builder/src/Cache/LayoutBuilderUiCacheContext.php b/core/modules/layout_builder/src/Cache/LayoutBuilderUiCacheContext.php
index 53b589452dcb8f924189c988a9913d4b3828a76c..4626d1cd86df4ca411c2e0628997bf7cdca8a8e3 100644
--- a/core/modules/layout_builder/src/Cache/LayoutBuilderUiCacheContext.php
+++ b/core/modules/layout_builder/src/Cache/LayoutBuilderUiCacheContext.php
@@ -8,6 +8,9 @@
  * Determines if an entity is being viewed in the Layout Builder UI.
  *
  * Cache context ID: 'route.name.is_layout_builder_ui'.
+ *
+ * @internal
+ *   Tagged services are internal.
  */
 class LayoutBuilderUiCacheContext extends RouteNameCacheContext {
 
diff --git a/core/modules/layout_builder/src/Controller/AddSectionController.php b/core/modules/layout_builder/src/Controller/AddSectionController.php
index abe7df3876e921ff2d39cc184dc0c28d2886bf51..a32bcb1e429cffa64297494f25a4e9a84d155a77 100644
--- a/core/modules/layout_builder/src/Controller/AddSectionController.php
+++ b/core/modules/layout_builder/src/Controller/AddSectionController.php
@@ -14,6 +14,7 @@
  * Defines a controller to add a new section.
  *
  * @internal
+ *   Controller classes are internal.
  */
 class AddSectionController implements ContainerInjectionInterface {
 
diff --git a/core/modules/layout_builder/src/Controller/ChooseBlockController.php b/core/modules/layout_builder/src/Controller/ChooseBlockController.php
index 99397d1b5921d7ca77bbc4ab3e82df1fb9e11056..a20a351d56e42b87c76a04badcff9f8f72a7b914 100644
--- a/core/modules/layout_builder/src/Controller/ChooseBlockController.php
+++ b/core/modules/layout_builder/src/Controller/ChooseBlockController.php
@@ -18,6 +18,7 @@
  * Defines a controller to choose a new block.
  *
  * @internal
+ *   Controller classes are internal.
  */
 class ChooseBlockController implements ContainerInjectionInterface {
 
diff --git a/core/modules/layout_builder/src/Controller/ChooseSectionController.php b/core/modules/layout_builder/src/Controller/ChooseSectionController.php
index 714c4770f82870f62d8c9afb027207f8a2fcdf36..ec27e92626f36f89177a32b6f34fa2b8ab9de847 100644
--- a/core/modules/layout_builder/src/Controller/ChooseSectionController.php
+++ b/core/modules/layout_builder/src/Controller/ChooseSectionController.php
@@ -16,6 +16,7 @@
  * Defines a controller to choose a new section.
  *
  * @internal
+ *   Controller classes are internal.
  */
 class ChooseSectionController implements ContainerInjectionInterface {
 
diff --git a/core/modules/layout_builder/src/Controller/LayoutBuilderController.php b/core/modules/layout_builder/src/Controller/LayoutBuilderController.php
index 3c1920a3758126f86beddfe6eac9a1fbe4b07b11..9307f8062e9718b52df9b3ca925bf10911e04a1a 100644
--- a/core/modules/layout_builder/src/Controller/LayoutBuilderController.php
+++ b/core/modules/layout_builder/src/Controller/LayoutBuilderController.php
@@ -9,6 +9,7 @@
  * Defines a controller to provide the Layout Builder admin UI.
  *
  * @internal
+ *   Controller classes are internal.
  */
 class LayoutBuilderController {
 
diff --git a/core/modules/layout_builder/src/Controller/LayoutRebuildTrait.php b/core/modules/layout_builder/src/Controller/LayoutRebuildTrait.php
index 2cda6ee31cd6a8458fe498848e5c6a947bc18f5e..b8664edc51ac3a30d6ebbacd1b1f28c1734c461c 100644
--- a/core/modules/layout_builder/src/Controller/LayoutRebuildTrait.php
+++ b/core/modules/layout_builder/src/Controller/LayoutRebuildTrait.php
@@ -9,8 +9,6 @@
 
 /**
  * Provides AJAX responses to rebuild the Layout Builder.
- *
- * @internal
  */
 trait LayoutRebuildTrait {
 
diff --git a/core/modules/layout_builder/src/Controller/MoveBlockController.php b/core/modules/layout_builder/src/Controller/MoveBlockController.php
index 20f5c37cc9be10bb3c6d67a579d9b1f1678eb83e..2f6f6b2349164aeb7bab9851daec9e4e00c3c189 100644
--- a/core/modules/layout_builder/src/Controller/MoveBlockController.php
+++ b/core/modules/layout_builder/src/Controller/MoveBlockController.php
@@ -11,6 +11,7 @@
  * Defines a controller to move a block.
  *
  * @internal
+ *   Controller classes are internal.
  */
 class MoveBlockController implements ContainerInjectionInterface {
 
diff --git a/core/modules/layout_builder/src/DefaultsSectionStorageInterface.php b/core/modules/layout_builder/src/DefaultsSectionStorageInterface.php
index 0bcaa387e0263c3d24b81d24d1b0d44b7e96a26a..a21005a02e214f4ffbcf2c422518cce895c633e4 100644
--- a/core/modules/layout_builder/src/DefaultsSectionStorageInterface.php
+++ b/core/modules/layout_builder/src/DefaultsSectionStorageInterface.php
@@ -7,11 +7,6 @@
 /**
  * Defines an interface for an object that stores layout sections for defaults.
  *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
- *
  * @todo Refactor this interface in https://www.drupal.org/node/2985362.
  */
 interface DefaultsSectionStorageInterface extends SectionStorageInterface, ThirdPartySettingsInterface, LayoutBuilderEnabledInterface {
diff --git a/core/modules/layout_builder/src/Element/LayoutBuilder.php b/core/modules/layout_builder/src/Element/LayoutBuilder.php
index d767899de9b5b9fbc48e1277f9967162e51b1359..ec75e16bac90e991b92149ee0b143577d2acf089 100644
--- a/core/modules/layout_builder/src/Element/LayoutBuilder.php
+++ b/core/modules/layout_builder/src/Element/LayoutBuilder.php
@@ -20,6 +20,9 @@
  * Defines a render element for building the Layout Builder UI.
  *
  * @RenderElement("layout_builder")
+ *
+ * @internal
+ *   Plugin classes are internal.
  */
 class LayoutBuilder extends RenderElement implements ContainerFactoryPluginInterface {
 
diff --git a/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php b/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php
index abb65ca7c1c3f6613b754ddff92393197a4d7f5e..82c8210c2318a637dbe4e0e96a9568f0e7e93581 100644
--- a/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php
+++ b/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php
@@ -25,11 +25,6 @@
 
 /**
  * Provides an entity view display entity that has a layout.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 class LayoutBuilderEntityViewDisplay extends BaseEntityViewDisplay implements LayoutEntityDisplayInterface {
 
diff --git a/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplayStorage.php b/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplayStorage.php
index e00a2b46306692c487d611cf297c971511f020a7..d701213f9eecee0e56e139fb13b3caf41ceca47f 100644
--- a/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplayStorage.php
+++ b/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplayStorage.php
@@ -10,9 +10,7 @@
  * Provides storage for entity view display entities that have layouts.
  *
  * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
+ *   Entity handlers are internal.
  */
 class LayoutBuilderEntityViewDisplayStorage extends ConfigEntityStorage {
 
diff --git a/core/modules/layout_builder/src/Entity/LayoutEntityDisplayInterface.php b/core/modules/layout_builder/src/Entity/LayoutEntityDisplayInterface.php
index 51151bd81c10944ba8327ad13bcb7b32106de47c..0122c39955b44f7506052779ebd146e3a144df91 100644
--- a/core/modules/layout_builder/src/Entity/LayoutEntityDisplayInterface.php
+++ b/core/modules/layout_builder/src/Entity/LayoutEntityDisplayInterface.php
@@ -9,11 +9,6 @@
 /**
  * Provides an interface for entity displays that have layout.
  *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
- *
  * @todo Refactor this interface in https://www.drupal.org/node/2985362.
  */
 interface LayoutEntityDisplayInterface extends EntityDisplayInterface, SectionListInterface, LayoutBuilderEnabledInterface {
diff --git a/core/modules/layout_builder/src/Event/SectionComponentBuildRenderArrayEvent.php b/core/modules/layout_builder/src/Event/SectionComponentBuildRenderArrayEvent.php
index 9047e6e9dc52efc51f06ef8d03f92e9cb3d09ee2..b971adcc7e5f6e9287c16ab3ff1f2629a1349fe1 100644
--- a/core/modules/layout_builder/src/Event/SectionComponentBuildRenderArrayEvent.php
+++ b/core/modules/layout_builder/src/Event/SectionComponentBuildRenderArrayEvent.php
@@ -13,11 +13,6 @@
  * build array in this event.
  *
  * @see \Drupal\layout_builder\LayoutBuilderEvents::SECTION_COMPONENT_BUILD_RENDER_ARRAY
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 class SectionComponentBuildRenderArrayEvent extends Event {
 
diff --git a/core/modules/layout_builder/src/EventSubscriber/BlockComponentRenderArray.php b/core/modules/layout_builder/src/EventSubscriber/BlockComponentRenderArray.php
index e352764cce3210005a16d0f04259b05dba5a0184..cbb09c4f4f2982175e120fc796927a061b732303 100644
--- a/core/modules/layout_builder/src/EventSubscriber/BlockComponentRenderArray.php
+++ b/core/modules/layout_builder/src/EventSubscriber/BlockComponentRenderArray.php
@@ -19,9 +19,7 @@
  * Builds render arrays and handles access for all block components.
  *
  * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
+ *   Tagged services are internal.
  */
 class BlockComponentRenderArray implements EventSubscriberInterface {
 
diff --git a/core/modules/layout_builder/src/EventSubscriber/SetInlineBlockDependency.php b/core/modules/layout_builder/src/EventSubscriber/SetInlineBlockDependency.php
index 23e965be8654944b557a5f16a969f3905bde30b1..d1ff4ad3dcb06858bcdb90e7ddde2d0f21e018d7 100644
--- a/core/modules/layout_builder/src/EventSubscriber/SetInlineBlockDependency.php
+++ b/core/modules/layout_builder/src/EventSubscriber/SetInlineBlockDependency.php
@@ -27,6 +27,7 @@
  * the dependency.
  *
  * @internal
+ *   Tagged services are internal.
  *
  * @see \Drupal\file\FileAccessControlHandler::checkAccess()
  * @see \Drupal\block_content\BlockContentAccessControlHandler::checkAccess()
diff --git a/core/modules/layout_builder/src/Field/LayoutSectionItemList.php b/core/modules/layout_builder/src/Field/LayoutSectionItemList.php
index 657ae19cfdc3bc494e59ba1fb1c11df2afd08f97..58e78f2562631839c57a352edf149e7d3a3ed173 100644
--- a/core/modules/layout_builder/src/Field/LayoutSectionItemList.php
+++ b/core/modules/layout_builder/src/Field/LayoutSectionItemList.php
@@ -14,6 +14,7 @@
  * Defines a item list class for layout section fields.
  *
  * @internal
+ *   Plugin classes are internal.
  *
  * @see \Drupal\layout_builder\Plugin\Field\FieldType\LayoutSectionItem
  */
diff --git a/core/modules/layout_builder/src/Form/AddBlockForm.php b/core/modules/layout_builder/src/Form/AddBlockForm.php
index ccfea97e2fcd742b1e8bb1dece9d7a95114d0577..6f73133de718a6dd2f44c6072dffe073e47b43f4 100644
--- a/core/modules/layout_builder/src/Form/AddBlockForm.php
+++ b/core/modules/layout_builder/src/Form/AddBlockForm.php
@@ -11,6 +11,7 @@
  * Provides a form to add a block.
  *
  * @internal
+ *   Form classes are internal.
  */
 class AddBlockForm extends ConfigureBlockFormBase {
 
diff --git a/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php b/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php
index c2802a4a3d0ba911e9e5c6e2644423725f600e35..ced632a7e0107ac53247e476a805453265c69cb7 100644
--- a/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php
+++ b/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php
@@ -27,6 +27,7 @@
  * Provides a base form for configuring a block.
  *
  * @internal
+ *   Form classes are internal.
  */
 abstract class ConfigureBlockFormBase extends FormBase implements BaseFormIdInterface {
 
diff --git a/core/modules/layout_builder/src/Form/ConfigureSectionForm.php b/core/modules/layout_builder/src/Form/ConfigureSectionForm.php
index 82fce6156b2f09e454af29c8c505c253edc72700..a6d4ec87141bad21d9d8daede16a854634c00e22 100644
--- a/core/modules/layout_builder/src/Form/ConfigureSectionForm.php
+++ b/core/modules/layout_builder/src/Form/ConfigureSectionForm.php
@@ -21,6 +21,7 @@
  * Provides a form for configuring a layout section.
  *
  * @internal
+ *   Form classes are internal.
  */
 class ConfigureSectionForm extends FormBase {
 
diff --git a/core/modules/layout_builder/src/Form/DefaultsEntityForm.php b/core/modules/layout_builder/src/Form/DefaultsEntityForm.php
index 538cd1e98c1ccabed91ef1308ca4a68f03fcc9f4..b95ddd3bad37ef49980b81c1fc8d1353b0c9f104 100644
--- a/core/modules/layout_builder/src/Form/DefaultsEntityForm.php
+++ b/core/modules/layout_builder/src/Form/DefaultsEntityForm.php
@@ -15,6 +15,7 @@
  * Provides a form containing the Layout Builder UI for defaults.
  *
  * @internal
+ *   Form classes are internal.
  */
 class DefaultsEntityForm extends EntityForm {
 
diff --git a/core/modules/layout_builder/src/Form/DiscardLayoutChangesForm.php b/core/modules/layout_builder/src/Form/DiscardLayoutChangesForm.php
index 311bc7df3ae326fafe0b66335f85e78d11c4bdcc..7e44a03675a90420abf41a42f31dd4fa8362af1d 100644
--- a/core/modules/layout_builder/src/Form/DiscardLayoutChangesForm.php
+++ b/core/modules/layout_builder/src/Form/DiscardLayoutChangesForm.php
@@ -11,6 +11,9 @@
 
 /**
  * Discards any pending changes to the layout.
+ *
+ * @internal
+ *   Form classes are internal.
  */
 class DiscardLayoutChangesForm extends ConfirmFormBase {
 
diff --git a/core/modules/layout_builder/src/Form/LayoutBuilderDisableForm.php b/core/modules/layout_builder/src/Form/LayoutBuilderDisableForm.php
index 48b42b740daac7c703025b543e57909f6ec99ecd..0a1eb58f73cd6db05bd1be4fb7aeeaa8bc648357 100644
--- a/core/modules/layout_builder/src/Form/LayoutBuilderDisableForm.php
+++ b/core/modules/layout_builder/src/Form/LayoutBuilderDisableForm.php
@@ -12,6 +12,9 @@
 
 /**
  * Disables Layout Builder for a given default.
+ *
+ * @internal
+ *   Form classes are internal.
  */
 class LayoutBuilderDisableForm extends ConfirmFormBase {
 
diff --git a/core/modules/layout_builder/src/Form/LayoutBuilderEntityViewDisplayForm.php b/core/modules/layout_builder/src/Form/LayoutBuilderEntityViewDisplayForm.php
index 72edc2f5b78901ca6c9409c4b29785d52ff13fb2..12049f55c623ba3c336c5aa587db7fb1048dcca1 100644
--- a/core/modules/layout_builder/src/Form/LayoutBuilderEntityViewDisplayForm.php
+++ b/core/modules/layout_builder/src/Form/LayoutBuilderEntityViewDisplayForm.php
@@ -14,9 +14,7 @@
  * Edit form for the LayoutBuilderEntityViewDisplay entity type.
  *
  * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
+ *   Form classes are internal.
  */
 class LayoutBuilderEntityViewDisplayForm extends EntityViewDisplayEditForm {
 
diff --git a/core/modules/layout_builder/src/Form/LayoutRebuildConfirmFormBase.php b/core/modules/layout_builder/src/Form/LayoutRebuildConfirmFormBase.php
index 06f09ae9b703736bbaf6107c9d6701534b0cea34..5cf9a3ea8db2331a85fd23360444766c18702905 100644
--- a/core/modules/layout_builder/src/Form/LayoutRebuildConfirmFormBase.php
+++ b/core/modules/layout_builder/src/Form/LayoutRebuildConfirmFormBase.php
@@ -15,6 +15,7 @@
  * Provides a base class for confirmation forms that rebuild the Layout Builder.
  *
  * @internal
+ *   Form classes are internal.
  */
 abstract class LayoutRebuildConfirmFormBase extends ConfirmFormBase {
 
diff --git a/core/modules/layout_builder/src/Form/MoveBlockForm.php b/core/modules/layout_builder/src/Form/MoveBlockForm.php
index d8205f95255c7c1e92532fcdca1e9dcebbcb9cc9..49e97afa72ab828f2641ed509bf7751ec556411c 100644
--- a/core/modules/layout_builder/src/Form/MoveBlockForm.php
+++ b/core/modules/layout_builder/src/Form/MoveBlockForm.php
@@ -13,6 +13,9 @@
 
 /**
  * Provides a form for moving a block.
+ *
+ * @internal
+ *   Form classes are internal.
  */
 class MoveBlockForm extends FormBase {
 
diff --git a/core/modules/layout_builder/src/Form/OverridesEntityForm.php b/core/modules/layout_builder/src/Form/OverridesEntityForm.php
index 2c523a3197ce81f922c98628dfcbf134a3c5fceb..8b7ba87fbbd563c49860c2118188afef3d351a3a 100644
--- a/core/modules/layout_builder/src/Form/OverridesEntityForm.php
+++ b/core/modules/layout_builder/src/Form/OverridesEntityForm.php
@@ -19,6 +19,7 @@
  * Provides a form containing the Layout Builder UI for overrides.
  *
  * @internal
+ *   Form classes are internal.
  */
 class OverridesEntityForm extends ContentEntityForm {
 
diff --git a/core/modules/layout_builder/src/Form/RemoveBlockForm.php b/core/modules/layout_builder/src/Form/RemoveBlockForm.php
index 001464b216e14c2fcc919c9776873b09d9f8cf8f..128a5147031761865289edeb09d651e5f3c4edbb 100644
--- a/core/modules/layout_builder/src/Form/RemoveBlockForm.php
+++ b/core/modules/layout_builder/src/Form/RemoveBlockForm.php
@@ -9,6 +9,7 @@
  * Provides a form to confirm the removal of a block.
  *
  * @internal
+ *   Form classes are internal.
  */
 class RemoveBlockForm extends LayoutRebuildConfirmFormBase {
 
diff --git a/core/modules/layout_builder/src/Form/RemoveSectionForm.php b/core/modules/layout_builder/src/Form/RemoveSectionForm.php
index 13204ea2afafa6ccabc2f5c4012f52758523e438..7a0cb0fd4a1ed31d2fe8e3a0584f9af56169e099 100644
--- a/core/modules/layout_builder/src/Form/RemoveSectionForm.php
+++ b/core/modules/layout_builder/src/Form/RemoveSectionForm.php
@@ -9,6 +9,7 @@
  * Provides a form to confirm the removal of a section.
  *
  * @internal
+ *   Form classes are internal.
  */
 class RemoveSectionForm extends LayoutRebuildConfirmFormBase {
 
diff --git a/core/modules/layout_builder/src/Form/RevertOverridesForm.php b/core/modules/layout_builder/src/Form/RevertOverridesForm.php
index 7d1b3c9fb9fedc3e5b82ef77e3c6eac3af2ed36b..e352c768f8c2915700c68d205ba02b3a98aecb58 100644
--- a/core/modules/layout_builder/src/Form/RevertOverridesForm.php
+++ b/core/modules/layout_builder/src/Form/RevertOverridesForm.php
@@ -12,6 +12,9 @@
 
 /**
  * Reverts the overridden layout to the defaults.
+ *
+ * @internal
+ *   Form classes are internal.
  */
 class RevertOverridesForm extends ConfirmFormBase {
 
diff --git a/core/modules/layout_builder/src/Form/UpdateBlockForm.php b/core/modules/layout_builder/src/Form/UpdateBlockForm.php
index 59cf91fd56a284ca4d61cf68952b8ef20f63ef4e..5b6f5281048c05eb8ba5dbb2d1634323cb2e343c 100644
--- a/core/modules/layout_builder/src/Form/UpdateBlockForm.php
+++ b/core/modules/layout_builder/src/Form/UpdateBlockForm.php
@@ -10,6 +10,7 @@
  * Provides a form to update a block.
  *
  * @internal
+ *   Form classes are internal.
  */
 class UpdateBlockForm extends ConfigureBlockFormBase {
 
diff --git a/core/modules/layout_builder/src/InlineBlockEntityOperations.php b/core/modules/layout_builder/src/InlineBlockEntityOperations.php
index 27c350b62751da7a1791cadec39a1a14db6d1868..37a14c1f58241ee089cfb62777fa4923040b9838 100644
--- a/core/modules/layout_builder/src/InlineBlockEntityOperations.php
+++ b/core/modules/layout_builder/src/InlineBlockEntityOperations.php
@@ -15,6 +15,7 @@
  * Defines a class for reacting to entity events related to Inline Blocks.
  *
  * @internal
+ *   This is an internal utility class wrapping hook implementations.
  */
 class InlineBlockEntityOperations implements ContainerInjectionInterface {
 
diff --git a/core/modules/layout_builder/src/LayoutBuilderEvents.php b/core/modules/layout_builder/src/LayoutBuilderEvents.php
index b680f98d341b45e9d73edcc82d2d2619dea3fdd4..5b19e1c1982ccb65cc7a17d699ba3c000ce28427 100644
--- a/core/modules/layout_builder/src/LayoutBuilderEvents.php
+++ b/core/modules/layout_builder/src/LayoutBuilderEvents.php
@@ -6,11 +6,6 @@
  * Defines events for the layout_builder module.
  *
  * @see \Drupal\layout_builder\Event\SectionComponentBuildRenderArrayEvent
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 final class LayoutBuilderEvents {
 
diff --git a/core/modules/layout_builder/src/LayoutBuilderOverridesPermissions.php b/core/modules/layout_builder/src/LayoutBuilderOverridesPermissions.php
index f166e388bb72d7d9fc429bf268be5cb0f07ae91e..20c6a5e22e58d6562b2b48ffefdce65ef032aec6 100644
--- a/core/modules/layout_builder/src/LayoutBuilderOverridesPermissions.php
+++ b/core/modules/layout_builder/src/LayoutBuilderOverridesPermissions.php
@@ -12,6 +12,9 @@
  * Provides dynamic permissions for Layout Builder overrides.
  *
  * @see \Drupal\layout_builder\Plugin\SectionStorage\OverridesSectionStorage::access()
+ *
+ * @internal
+ *   Dynamic permission callbacks are internal.
  */
 class LayoutBuilderOverridesPermissions implements ContainerInjectionInterface {
 
diff --git a/core/modules/layout_builder/src/LayoutBuilderServiceProvider.php b/core/modules/layout_builder/src/LayoutBuilderServiceProvider.php
index c730b20b2d170b29aaa933ec8cb99d5afa0c1557..71005ee48cce5aef064e8a9a0ffeb744db6f0a2c 100644
--- a/core/modules/layout_builder/src/LayoutBuilderServiceProvider.php
+++ b/core/modules/layout_builder/src/LayoutBuilderServiceProvider.php
@@ -17,6 +17,7 @@
  * dynamically.
  *
  * @internal
+ *   Service providers are internal.
  *
  * @see \Drupal\layout_builder\EventSubscriber\SetInlineBlockDependency
  */
diff --git a/core/modules/layout_builder/src/LayoutEntityHelperTrait.php b/core/modules/layout_builder/src/LayoutEntityHelperTrait.php
index c85c16073bc77fd657cc76399bfbe8ba41ba8ba7..e1c4216ce7ecbf444d96f07360148ab8c1d6c344 100644
--- a/core/modules/layout_builder/src/LayoutEntityHelperTrait.php
+++ b/core/modules/layout_builder/src/LayoutEntityHelperTrait.php
@@ -15,8 +15,6 @@
 
 /**
  * Methods to help with entities using the layout builder.
- *
- * @internal
  */
 trait LayoutEntityHelperTrait {
 
diff --git a/core/modules/layout_builder/src/LayoutTempstoreRepository.php b/core/modules/layout_builder/src/LayoutTempstoreRepository.php
index d8fbb47f292382bf298831590883710124586559..36b78948b361ed6abb443a8419425623f71c476e 100644
--- a/core/modules/layout_builder/src/LayoutTempstoreRepository.php
+++ b/core/modules/layout_builder/src/LayoutTempstoreRepository.php
@@ -6,8 +6,6 @@
 
 /**
  * Provides a mechanism for loading layouts from tempstore.
- *
- * @internal
  */
 class LayoutTempstoreRepository implements LayoutTempstoreRepositoryInterface {
 
diff --git a/core/modules/layout_builder/src/LayoutTempstoreRepositoryInterface.php b/core/modules/layout_builder/src/LayoutTempstoreRepositoryInterface.php
index 67dc59ca99d807d34b60a44778a138f5df88dca4..a4220b00f16c6fbe0259aaf2ccd98b9a2d00a4c0 100644
--- a/core/modules/layout_builder/src/LayoutTempstoreRepositoryInterface.php
+++ b/core/modules/layout_builder/src/LayoutTempstoreRepositoryInterface.php
@@ -4,11 +4,6 @@
 
 /**
  * Provides an interface for loading layouts from tempstore.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 interface LayoutTempstoreRepositoryInterface {
 
diff --git a/core/modules/layout_builder/src/Normalizer/LayoutEntityDisplayNormalizer.php b/core/modules/layout_builder/src/Normalizer/LayoutEntityDisplayNormalizer.php
index c4c7640471a5a95f5ba66d1da6fe38e24b0596ef..886304fa29e50758ea4a6191b37387e1208ec3ab 100644
--- a/core/modules/layout_builder/src/Normalizer/LayoutEntityDisplayNormalizer.php
+++ b/core/modules/layout_builder/src/Normalizer/LayoutEntityDisplayNormalizer.php
@@ -9,7 +9,7 @@
  * Normalizes/denormalizes LayoutEntityDisplay objects into an array structure.
  *
  * @internal
- *   All tagged services are internal.
+ *   Tagged services are internal.
  */
 class LayoutEntityDisplayNormalizer extends ConfigEntityNormalizer {
 
diff --git a/core/modules/layout_builder/src/OverridesSectionStorageInterface.php b/core/modules/layout_builder/src/OverridesSectionStorageInterface.php
index b00d04d488ca4fac0751bc9caac445916908e564..94ff3bea664ce0d97dd3ee68a655fa6cd4fae813 100644
--- a/core/modules/layout_builder/src/OverridesSectionStorageInterface.php
+++ b/core/modules/layout_builder/src/OverridesSectionStorageInterface.php
@@ -4,11 +4,6 @@
 
 /**
  * Defines an interface for an object that stores layout sections for overrides.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 interface OverridesSectionStorageInterface extends SectionStorageInterface {
 
@@ -19,7 +14,7 @@ interface OverridesSectionStorageInterface extends SectionStorageInterface {
    *   The defaults section storage.
    *
    * @todo Determine if this method needs a parameter in
-   *   https://www.drupal.org/project/drupal/issues/2936507.
+   *   https://www.drupal.org/project/drupal/issues/2907413.
    */
   public function getDefaultSectionStorage();
 
diff --git a/core/modules/layout_builder/src/Plugin/Block/FieldBlock.php b/core/modules/layout_builder/src/Plugin/Block/FieldBlock.php
index 645a09488ef284d391364b4e462d6e560afe9b44..b89f4630837c4d07e41c2fef37835ec5f8c9f373 100644
--- a/core/modules/layout_builder/src/Plugin/Block/FieldBlock.php
+++ b/core/modules/layout_builder/src/Plugin/Block/FieldBlock.php
@@ -30,6 +30,9 @@
  *   id = "field_block",
  *   deriver = "\Drupal\layout_builder\Plugin\Derivative\FieldBlockDeriver",
  * )
+ *
+ * @internal
+ *   Plugin classes are internal.
  */
 class FieldBlock extends BlockBase implements ContextAwarePluginInterface, ContainerFactoryPluginInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/DataType/SectionData.php b/core/modules/layout_builder/src/Plugin/DataType/SectionData.php
index 353c53fe7cca8ad323c3ecc57c220fee253854ce..8783904d492e55907868440bf7cbea0436fd695d 100644
--- a/core/modules/layout_builder/src/Plugin/DataType/SectionData.php
+++ b/core/modules/layout_builder/src/Plugin/DataType/SectionData.php
@@ -13,6 +13,9 @@
  *   label = @Translation("Layout Section"),
  *   description = @Translation("A layout section"),
  * )
+ *
+ * @internal
+ *   Plugin classes are internal.
  */
 class SectionData extends TypedData {
 
diff --git a/core/modules/layout_builder/src/Plugin/Derivative/ExtraFieldBlockDeriver.php b/core/modules/layout_builder/src/Plugin/Derivative/ExtraFieldBlockDeriver.php
index 1a6bb6699bcb097f79fdd8caff57031aac9e2d13..bb61ccc15663f45cab8d234b66f77aee6ed516d4 100644
--- a/core/modules/layout_builder/src/Plugin/Derivative/ExtraFieldBlockDeriver.php
+++ b/core/modules/layout_builder/src/Plugin/Derivative/ExtraFieldBlockDeriver.php
@@ -17,9 +17,7 @@
  * Provides entity field block definitions for every field.
  *
  * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
+ *   Plugin derivers are internal.
  */
 class ExtraFieldBlockDeriver extends DeriverBase implements ContainerDeriverInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/Derivative/FieldBlockDeriver.php b/core/modules/layout_builder/src/Plugin/Derivative/FieldBlockDeriver.php
index ae6771b118f7e69ed7d15aa54a3ac0b6394947b1..97ac8114096e913f20b892b5a2d674e7895ee15a 100644
--- a/core/modules/layout_builder/src/Plugin/Derivative/FieldBlockDeriver.php
+++ b/core/modules/layout_builder/src/Plugin/Derivative/FieldBlockDeriver.php
@@ -18,6 +18,7 @@
  * Provides entity field block definitions for every field.
  *
  * @internal
+ *   Plugin derivers are internal.
  */
 class FieldBlockDeriver extends DeriverBase implements ContainerDeriverInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/Derivative/InlineBlockDeriver.php b/core/modules/layout_builder/src/Plugin/Derivative/InlineBlockDeriver.php
index 1faeef1862b47d6eb51f480f2ce84648a34dc81b..2a9704bf1dc43998e39b6cc03afb833302e262e7 100644
--- a/core/modules/layout_builder/src/Plugin/Derivative/InlineBlockDeriver.php
+++ b/core/modules/layout_builder/src/Plugin/Derivative/InlineBlockDeriver.php
@@ -11,6 +11,7 @@
  * Provides inline block plugin definitions for all custom block types.
  *
  * @internal
+ *   Plugin derivers are internal.
  */
 class InlineBlockDeriver extends DeriverBase implements ContainerDeriverInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/Derivative/LayoutBuilderLocalTaskDeriver.php b/core/modules/layout_builder/src/Plugin/Derivative/LayoutBuilderLocalTaskDeriver.php
index 9e4a2ce42c4fd5bb41ce4ec084d3054d11467372..9ff31404ce0bdc3bbb4b46e9bb3815db2cd1e96e 100644
--- a/core/modules/layout_builder/src/Plugin/Derivative/LayoutBuilderLocalTaskDeriver.php
+++ b/core/modules/layout_builder/src/Plugin/Derivative/LayoutBuilderLocalTaskDeriver.php
@@ -16,6 +16,7 @@
  * @todo Remove this in https://www.drupal.org/project/drupal/issues/2936655.
  *
  * @internal
+ *   Plugin derivers are internal.
  */
 class LayoutBuilderLocalTaskDeriver extends DeriverBase implements ContainerDeriverInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php b/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
index 0865f0c7c54a25b9dba31061bb7135396d618ddd..e876583ce41dd5e4ee30bf4533312da9bf271467 100644
--- a/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
+++ b/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
@@ -13,6 +13,7 @@
  * Plugin implementation of the 'layout_section' field type.
  *
  * @internal
+ *   Plugin classes are internal.
  *
  * @FieldType(
  *   id = "layout_section",
diff --git a/core/modules/layout_builder/src/Plugin/Field/FieldWidget/LayoutBuilderWidget.php b/core/modules/layout_builder/src/Plugin/Field/FieldWidget/LayoutBuilderWidget.php
index 6bd40f7809624621d9a7293edc339c810efd27ad..38ffb792509e00bfeacf82313a3e931c4baa4dee 100644
--- a/core/modules/layout_builder/src/Plugin/Field/FieldWidget/LayoutBuilderWidget.php
+++ b/core/modules/layout_builder/src/Plugin/Field/FieldWidget/LayoutBuilderWidget.php
@@ -20,9 +20,7 @@
  * )
  *
  * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
+ *   Plugin classes are internal.
  */
 class LayoutBuilderWidget extends WidgetBase {
 
diff --git a/core/modules/layout_builder/src/Plugin/Layout/MultiWidthLayoutBase.php b/core/modules/layout_builder/src/Plugin/Layout/MultiWidthLayoutBase.php
index 56f2d646b9bee040195a7315b18e8097081977d1..71ab112dfc7760b18f40faea6daaba21bc738067 100644
--- a/core/modules/layout_builder/src/Plugin/Layout/MultiWidthLayoutBase.php
+++ b/core/modules/layout_builder/src/Plugin/Layout/MultiWidthLayoutBase.php
@@ -10,9 +10,7 @@
  * Base class of layouts with configurable widths.
  *
  * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
+ *   Plugin classes are internal.
  */
 abstract class MultiWidthLayoutBase extends LayoutDefault implements PluginFormInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/SectionStorage/DefaultsSectionStorage.php b/core/modules/layout_builder/src/Plugin/SectionStorage/DefaultsSectionStorage.php
index 98e6e34df2c04c6d3d401804f7e1c4a8ef9eabfd..8c6e8afb28f2b28eaa1cdc2495f84cfd6cfd99a9 100644
--- a/core/modules/layout_builder/src/Plugin/SectionStorage/DefaultsSectionStorage.php
+++ b/core/modules/layout_builder/src/Plugin/SectionStorage/DefaultsSectionStorage.php
@@ -37,9 +37,7 @@
  * )
  *
  * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
+ *   Plugin classes are internal.
  */
 class DefaultsSectionStorage extends SectionStorageBase implements ContainerFactoryPluginInterface, DefaultsSectionStorageInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/SectionStorage/OverridesSectionStorage.php b/core/modules/layout_builder/src/Plugin/SectionStorage/OverridesSectionStorage.php
index b35a9070e42278ba4ba28e4534ece2b8695a5b6d..cde6f497c56be3f2197b4f96a6d181c8c97f6c2b 100644
--- a/core/modules/layout_builder/src/Plugin/SectionStorage/OverridesSectionStorage.php
+++ b/core/modules/layout_builder/src/Plugin/SectionStorage/OverridesSectionStorage.php
@@ -44,9 +44,7 @@
  * )
  *
  * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
+ *   Plugin classes are internal.
  */
 class OverridesSectionStorage extends SectionStorageBase implements ContainerFactoryPluginInterface, OverridesSectionStorageInterface, SectionStorageLocalTaskProviderInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/SectionStorage/SectionStorageBase.php b/core/modules/layout_builder/src/Plugin/SectionStorage/SectionStorageBase.php
index 90c9a4250bd01de2e273b67720c09686f4a3f24c..8c6d506c1db9accfbca061547a789736adb896d6 100644
--- a/core/modules/layout_builder/src/Plugin/SectionStorage/SectionStorageBase.php
+++ b/core/modules/layout_builder/src/Plugin/SectionStorage/SectionStorageBase.php
@@ -11,11 +11,6 @@
 
 /**
  * Provides a base class for Section Storage types.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 abstract class SectionStorageBase extends ContextAwarePluginBase implements SectionStorageInterface, TempStoreIdentifierInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/SectionStorage/SectionStorageLocalTaskProviderInterface.php b/core/modules/layout_builder/src/Plugin/SectionStorage/SectionStorageLocalTaskProviderInterface.php
index a275d6340dd6504163d2547fa0eec557c2144d58..b7a662ea98e18838495c63ec05b79b028f7580e8 100644
--- a/core/modules/layout_builder/src/Plugin/SectionStorage/SectionStorageLocalTaskProviderInterface.php
+++ b/core/modules/layout_builder/src/Plugin/SectionStorage/SectionStorageLocalTaskProviderInterface.php
@@ -7,11 +7,6 @@
  *
  * @see \Drupal\layout_builder\Plugin\Derivative\LayoutBuilderLocalTaskDeriver
  * @see \Drupal\layout_builder\SectionStorageInterface
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 interface SectionStorageLocalTaskProviderInterface {
 
diff --git a/core/modules/layout_builder/src/QuickEditIntegration.php b/core/modules/layout_builder/src/QuickEditIntegration.php
index b2b9a62210f7e7f5519f84b5875c38d7720e5e0b..5492b4f3359aafd3834022b81884620e74ce64a4 100644
--- a/core/modules/layout_builder/src/QuickEditIntegration.php
+++ b/core/modules/layout_builder/src/QuickEditIntegration.php
@@ -22,6 +22,7 @@
  * Helper methods for Quick Edit module integration.
  *
  * @internal
+ *   This is an internal utility class wrapping hook implementations.
  */
 class QuickEditIntegration implements ContainerInjectionInterface {
 
@@ -92,8 +93,6 @@ public static function create(ContainerInterface $container) {
    *
    * @see hook_quickedit_render_field()
    * @see layout_builder_quickedit_render_field()
-   *
-   * @internal
    */
   public function entityViewAlter(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display) {
     if (!$entity instanceof FieldableEntityInterface || !isset($build['_layout_builder'])) {
@@ -243,8 +242,6 @@ public static function deconstructViewModeId($quick_edit_view_mode_id) {
    *
    * @return array
    *   The re-rendered field.
-   *
-   * @internal
    */
   public function quickEditRenderField(FieldableEntityInterface $entity, $field_name, $quick_edit_view_mode_id, $langcode) {
     list($entity_view_mode, $delta, $component_uuid) = static::deconstructViewModeId($quick_edit_view_mode_id);
diff --git a/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php b/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php
index 1046579458e0ff14bf10b552d6bb9e4feeded769..60d09379685c352718fa96e435014bbc1a8f5eb8 100644
--- a/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php
+++ b/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php
@@ -11,6 +11,7 @@
  * Provides routes for the Layout Builder UI.
  *
  * @internal
+ *   Tagged services are internal.
  */
 class LayoutBuilderRoutes implements EventSubscriberInterface {
 
diff --git a/core/modules/layout_builder/src/Routing/LayoutBuilderRoutesTrait.php b/core/modules/layout_builder/src/Routing/LayoutBuilderRoutesTrait.php
index 9b210355db2454ea633776b9c7cecb0656277d0c..aebc9755655b8f9f375e1825f0fe6eb6366d6321 100644
--- a/core/modules/layout_builder/src/Routing/LayoutBuilderRoutesTrait.php
+++ b/core/modules/layout_builder/src/Routing/LayoutBuilderRoutesTrait.php
@@ -11,11 +11,6 @@
 
 /**
  * Provides a trait for building routes for a Layout Builder UI.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 trait LayoutBuilderRoutesTrait {
 
diff --git a/core/modules/layout_builder/src/Routing/LayoutTempstoreParamConverter.php b/core/modules/layout_builder/src/Routing/LayoutTempstoreParamConverter.php
index 712f9ff850266d159df9440d66213928d7fd04a3..986c7527306354182a85f9da66c8068aa9a67896 100644
--- a/core/modules/layout_builder/src/Routing/LayoutTempstoreParamConverter.php
+++ b/core/modules/layout_builder/src/Routing/LayoutTempstoreParamConverter.php
@@ -11,6 +11,7 @@
  * Loads the section storage from the layout tempstore.
  *
  * @internal
+ *   Tagged services are internal.
  */
 class LayoutTempstoreParamConverter implements ParamConverterInterface {
 
diff --git a/core/modules/layout_builder/src/Section.php b/core/modules/layout_builder/src/Section.php
index c78692f42c8f30e5e64a2317dfe69b7cb6fb56ea..73225d8fb55e3b8d379089c4d090fbac62870c5a 100644
--- a/core/modules/layout_builder/src/Section.php
+++ b/core/modules/layout_builder/src/Section.php
@@ -13,16 +13,8 @@
  * - An array of settings for the layout plugin.
  * - An array of components that can be rendered in the section.
  *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
- *
  * @see \Drupal\Core\Layout\LayoutDefinition
  * @see \Drupal\layout_builder\SectionComponent
- *
- * @todo Determine whether an interface will be provided for this in
- *   https://www.drupal.org/project/drupal/issues/2930334.
  */
 class Section implements ThirdPartySettingsInterface {
 
diff --git a/core/modules/layout_builder/src/SectionComponent.php b/core/modules/layout_builder/src/SectionComponent.php
index 4937f7fbcde669fe61c644c043b2f787877bbdfd..4003f7e7e7de876e940b47a0c9c64afd8db4b4b0 100644
--- a/core/modules/layout_builder/src/SectionComponent.php
+++ b/core/modules/layout_builder/src/SectionComponent.php
@@ -14,19 +14,9 @@
  * \Drupal\Core\Block\BlockPluginInterface, and contain the layout region
  * within the section layout where the component will be rendered.
  *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
- *
  * @see \Drupal\Core\Layout\LayoutDefinition
  * @see \Drupal\layout_builder\Section
  * @see \Drupal\layout_builder\SectionStorageInterface
- *
- * @todo Determine whether to retain the name 'component' in
- *   https://www.drupal.org/project/drupal/issues/2929783.
- * @todo Determine whether an interface will be provided for this in
- *   https://www.drupal.org/project/drupal/issues/2930334.
  */
 class SectionComponent {
 
diff --git a/core/modules/layout_builder/src/SectionListInterface.php b/core/modules/layout_builder/src/SectionListInterface.php
index 767a27ae75929d916fd2e65f1cd2d9b15d5cd40d..9bf2009321b19291ac16202f1c5572e46e77e6a5 100644
--- a/core/modules/layout_builder/src/SectionListInterface.php
+++ b/core/modules/layout_builder/src/SectionListInterface.php
@@ -5,11 +5,6 @@
 /**
  * Defines the interface for an object that stores layout sections.
  *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
- *
  * @see \Drupal\layout_builder\Section
  */
 interface SectionListInterface extends \Countable {
diff --git a/core/modules/layout_builder/src/SectionStorage/SectionStorageDefinition.php b/core/modules/layout_builder/src/SectionStorage/SectionStorageDefinition.php
index bccd7d14846b9004a4c66dccebddbbe590121b93..eb9e5afc4f065e1820526590d356667b4d37188f 100644
--- a/core/modules/layout_builder/src/SectionStorage/SectionStorageDefinition.php
+++ b/core/modules/layout_builder/src/SectionStorage/SectionStorageDefinition.php
@@ -8,11 +8,6 @@
 
 /**
  * Provides section storage type plugin definition.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 class SectionStorageDefinition extends PluginDefinition implements ContextAwarePluginDefinitionInterface {
 
diff --git a/core/modules/layout_builder/src/SectionStorage/SectionStorageManager.php b/core/modules/layout_builder/src/SectionStorage/SectionStorageManager.php
index fd14bac830bdee37fca91ca189b9630f586804cc..0257b9a2c8dea1d47629a52f56be666a0f0df090 100644
--- a/core/modules/layout_builder/src/SectionStorage/SectionStorageManager.php
+++ b/core/modules/layout_builder/src/SectionStorage/SectionStorageManager.php
@@ -19,11 +19,6 @@
  * via \Drupal\layout_builder\SectionStorage\SectionStorageManagerInterface.
  * While internally depending on the parent class is necessary, external code
  * should only use the methods available on that interface.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 class SectionStorageManager extends DefaultPluginManager implements SectionStorageManagerInterface {
 
diff --git a/core/modules/layout_builder/src/SectionStorage/SectionStorageManagerInterface.php b/core/modules/layout_builder/src/SectionStorage/SectionStorageManagerInterface.php
index 82e7dafbe81d2619de317ade8d46e949e98445ac..d2083066ea5402dc64ac6292a95ff2f71c8dc5cd 100644
--- a/core/modules/layout_builder/src/SectionStorage/SectionStorageManagerInterface.php
+++ b/core/modules/layout_builder/src/SectionStorage/SectionStorageManagerInterface.php
@@ -7,11 +7,6 @@
 
 /**
  * Provides the interface for a plugin manager of section storage types.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 interface SectionStorageManagerInterface extends DiscoveryInterface {
 
diff --git a/core/modules/layout_builder/src/SectionStorage/SectionStorageTrait.php b/core/modules/layout_builder/src/SectionStorage/SectionStorageTrait.php
index 4cb2b07c308a54217f56ff5e493f9622a9baee39..410e406c50ced45faf7a4ab71e2ff8642e2904eb 100644
--- a/core/modules/layout_builder/src/SectionStorage/SectionStorageTrait.php
+++ b/core/modules/layout_builder/src/SectionStorage/SectionStorageTrait.php
@@ -6,11 +6,6 @@
 
 /**
  * Provides a trait for storing sections on an object.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 trait SectionStorageTrait {
 
diff --git a/core/modules/layout_builder/src/SectionStorageInterface.php b/core/modules/layout_builder/src/SectionStorageInterface.php
index d9063f06c4ef409813dd79e8407bfa549d636c34..41891bb7f0bbf81d3b26f19d682dae4c206d7a05 100644
--- a/core/modules/layout_builder/src/SectionStorageInterface.php
+++ b/core/modules/layout_builder/src/SectionStorageInterface.php
@@ -11,11 +11,6 @@
 
 /**
  * Defines an interface for Section Storage type plugins.
- *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 interface SectionStorageInterface extends SectionListInterface, PluginInspectionInterface, ContextAwarePluginInterface, AccessibleInterface {
 
diff --git a/core/modules/layout_builder/src/TempStoreIdentifierInterface.php b/core/modules/layout_builder/src/TempStoreIdentifierInterface.php
index a96e8606eb47723483e61119fcbb156b8e2091ba..037d778ffb9b0260aa3bd734a10375571645da25 100644
--- a/core/modules/layout_builder/src/TempStoreIdentifierInterface.php
+++ b/core/modules/layout_builder/src/TempStoreIdentifierInterface.php
@@ -5,11 +5,6 @@
 /**
  * Provides an interface that allows an object to provide its own tempstore key.
  *
- * @internal
- *   Layout Builder is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
- *
  * @todo Move to \Drupal\Core\TempStore in https://www.drupal.org/node/3026957.
  */
 interface TempStoreIdentifierInterface {
diff --git a/core/themes/seven/css/components/layout-builder-content-translation.css b/core/themes/seven/css/components/layout-builder-content-translation.css
new file mode 100644
index 0000000000000000000000000000000000000000..59ff37c19d84457d735ec31a6e18535efbad7783
--- /dev/null
+++ b/core/themes/seven/css/components/layout-builder-content-translation.css
@@ -0,0 +1,4 @@
+.layout-builder-translation-warning {
+  background: left 2px url(../../../../misc/icons/e29700/warning.svg) no-repeat;
+  padding-left: 20px;
+}
diff --git a/core/themes/seven/seven.libraries.yml b/core/themes/seven/seven.libraries.yml
index 6ae159416eb55b1e7f008388895cb1a11cf1ac35..645f4d3439d8a37b74e431a85c2d1efff95cc63f 100644
--- a/core/themes/seven/seven.libraries.yml
+++ b/core/themes/seven/seven.libraries.yml
@@ -131,3 +131,9 @@ media-form:
       css/components/media.css: {}
   dependencies:
     - media/form
+
+layout_builder_content_translation_admin:
+  version: VERSION
+  css:
+    component:
+      css/components/layout-builder-content-translation.css: {}
diff --git a/core/themes/seven/seven.theme b/core/themes/seven/seven.theme
index 479a4e310a28d9ba83a24d5379c5cbb11b591a1f..76cb9bf7729931dcb5cab8acf5b6c34d6c3b8292 100644
--- a/core/themes/seven/seven.theme
+++ b/core/themes/seven/seven.theme
@@ -178,3 +178,10 @@ function seven_form_media_form_alter(&$form, FormStateInterface $form_state) {
     $form['#attached']['library'][] = 'seven/media-form';
   }
 }
+
+/**
+ * Implements hook_form_FORM_ID_alter() for language_content_settings_form().
+ */
+function seven_form_language_content_settings_form_alter(array &$form, FormStateInterface $form_state) {
+  $form['#attached']['library'][] = 'seven/layout_builder_content_translation_admin';
+}
diff --git a/core/themes/stable/css/layout_builder/layout-builder.css b/core/themes/stable/css/layout_builder/layout-builder.css
new file mode 100644
index 0000000000000000000000000000000000000000..a4d38e60880d7e627e8f900dfbf06add3497f296
--- /dev/null
+++ b/core/themes/stable/css/layout_builder/layout-builder.css
@@ -0,0 +1,217 @@
+.layout-builder {
+  background-color: #fff;
+  border: 3px solid #2f91da;
+  padding: 1.5em 1.5em 0.5em;
+}
+
+.layout-builder__add-section {
+  background-color: #f7f7f7;
+  width: 100%;
+  outline: 2px dashed #979797;
+  padding: 1.5em 0;
+  text-align: center;
+  margin-bottom: 1.5em;
+}
+
+.layout-builder__link--add {
+  color: #686868;
+  border-bottom: none;
+  padding-left: 24px;
+  background: url(../../../../misc/icons/686868/plus.svg) transparent top left / 16px 16px no-repeat;
+}
+
+.layout-builder__link--add:hover,
+.layout-builder__link--add:active,
+.layout-builder__link--add:focus {
+  border-bottom-style: none;
+  color: #000;
+}
+
+.layout-builder__section {
+  margin-bottom: 1.5em;
+}
+
+.layout-builder__section .ui-sortable-helper {
+  background-color: #fff;
+  outline: 2px solid #f7f7f7;
+}
+
+.layout-builder__section .ui-state-drop {
+  background-color: #ffd;
+  outline: 2px dashed #fedb60;
+  margin: 20px;
+  padding: 30px;
+}
+
+.layout-builder__region {
+  outline: 2px dashed #2f91da;
+}
+
+.layout-builder__add-block {
+  background-color: #eff6fc;
+  padding: 1.5em 0;
+  text-align: center;
+}
+
+.layout-builder__link--remove {
+  position: relative;
+  background: url(../../../../misc/icons/bebebe/ex.svg) #fff center center / 16px 16px no-repeat;
+  border: 1px solid #ccc;
+  box-sizing: border-box;
+  font-size: 1rem;
+  padding: 0;
+  height: 26px;
+  width: 26px;
+  white-space: nowrap;
+  text-indent: -9999px;
+  display: inline-block;
+  border-radius: 26px;
+  margin-left: -10px;
+  margin-right: 6px;
+  z-index: 2;
+}
+
+.layout-builder__link--remove:hover {
+  background-image: url(../../../../misc/icons/787878/ex.svg);
+}
+
+.layout-builder-block {
+  padding: 1.5em;
+  cursor: move;
+}
+
+.layout-builder-block [tabindex="-1"] {
+  pointer-events: none;
+}
+
+.layout-builder__message .messages {
+  background-repeat: no-repeat;
+}
+.layout-builder__message--defaults .messages {
+  background-image: url("../images/globe.svg");
+}
+.layout-builder__message--overrides .messages {
+  background-image: url("../images/location.svg");
+}
+
+/**
+ * @todo Remove Umami specific styling in https://www.drupal.org/node/3043228.
+ */
+.layout-builder__message .messages .messages__content {
+  background: none;
+}
+
+.layout-builder-block__content-preview-placeholder-label {
+  margin: 0;
+  line-height: 1.4;
+  font-size: 1.429em;
+  text-align: center;
+}
+
+.layout-builder--content-preview-disabled .layout-builder-block {
+  border-bottom: 2px dashed #979797;
+  margin: 0;
+}
+
+#drupal-off-canvas .layout-selection li {
+  display: block;
+  padding-bottom: 1em;
+}
+
+#drupal-off-canvas .layout-selection li a {
+  display: block;
+  padding-top: 0.55em;
+}
+
+#drupal-off-canvas .inline-block-create-button {
+  display: block;
+  padding: 24px;
+  padding-left: 44px;
+  font-size: 16px;
+  color: #eee;
+  border-bottom: 1px solid #333;
+  background: url(../../../../misc/icons/bebebe/plus.svg) transparent 16px no-repeat;
+}
+
+#drupal-off-canvas .inline-block-create-button,
+#drupal-off-canvas .inline-block-list__item {
+  margin: 0 -20px;
+  background-color: #444;
+}
+
+#drupal-off-canvas .inline-block-create-button:hover,
+#drupal-off-canvas .inline-block-list__item:hover {
+  background-color: #333;
+}
+
+#drupal-off-canvas .inline-block-list {
+  margin-bottom: 15px;
+}
+
+#drupal-off-canvas .inline-block-list__item {
+  display: block;
+  padding: 15px 0 15px 25px;
+}
+
+.layout-builder__add-section.is-layout-builder-highlighted {
+  margin-bottom: calc(1.5em - 8px);
+  outline: none;
+}
+.layout-builder__layout.is-layout-builder-highlighted,
+.layout-builder-block.is-layout-builder-highlighted,
+.layout-builder__add-block.is-layout-builder-highlighted {
+  margin: -4px -2px;
+  position: relative;
+  z-index: 1;
+}
+.layout-builder__add-block.is-layout-builder-highlighted,
+.layout-builder__add-section.is-layout-builder-highlighted,
+.layout-builder__layout.is-layout-builder-highlighted:before,
+.layout-builder__layout.is-layout-builder-highlighted,
+.layout-builder-block.is-layout-builder-highlighted {
+  border: 4px solid #000;
+}
+
+/* Highlight the active block in the Move Block dialog. */
+#drupal-off-canvas .layout-builder-components-table__block-label--current {
+  border-left: solid 5px;
+  padding-left: 17px;
+}
+
+/**
+ * @todo remove in https://www.drupal.org/project/drupal/issues/3042127
+ *   This rule ensures the row weight dropdowns in the Move Block dialog
+ *   maintain the background color of their container when they are hovered
+ *   over or are inside the active row.
+ */
+#drupal-off-canvas .layout-builder-components-table__row .form-item {
+  background-color: transparent;
+}
+
+.layout-builder__region-label,
+.layout-builder__section-label {
+  display: none;
+}
+
+.layout-builder--move-blocks-active .layout-builder__region-label {
+  display: block;
+}
+
+.layout-builder--move-blocks-active .layout-builder__section-label {
+  display: inline;
+}
+
+.layout__region-info {
+  padding: 0.5em;
+  text-align: center;
+  border-bottom: 2px dashed #979797;
+}
+
+/**
+ * Remove "You have unsaved changes" warning because Layout Builder always has
+ * unsaved changes until "Save layout" is submitted.
+ * @todo create issue for todo.
+ */
+.layout-builder-components-table .tabledrag-changed-warning {
+  display: none !important;
+}
diff --git a/core/themes/stable/layouts/fourcol_section/fourcol_section.css b/core/themes/stable/layouts/fourcol_section/fourcol_section.css
new file mode 100644
index 0000000000000000000000000000000000000000..de1f3f87f39625074f3af7435faa07680d966a9d
--- /dev/null
+++ b/core/themes/stable/layouts/fourcol_section/fourcol_section.css
@@ -0,0 +1,19 @@
+/*
+ * @file
+ * Provides the layout styles for four-column layout section.
+ */
+
+.layout--fourcol-section {
+  display: flex;
+  flex-wrap: wrap;
+}
+
+.layout--fourcol-section > .layout__region {
+  flex: 0 1 100%;
+}
+
+@media screen and (min-width: 40em) {
+  .layout--fourcol-section > .layout__region {
+    flex: 0 1 25%;
+  }
+}
diff --git a/core/themes/stable/layouts/fourcol_section/layout--fourcol-section.html.twig b/core/themes/stable/layouts/fourcol_section/layout--fourcol-section.html.twig
new file mode 100644
index 0000000000000000000000000000000000000000..9a380f76e01dc3d54252c76ed86e4a50fd5b378f
--- /dev/null
+++ b/core/themes/stable/layouts/fourcol_section/layout--fourcol-section.html.twig
@@ -0,0 +1,47 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a four-column 25%-25%-25%-25% layout.
+ *
+ * Available variables:
+ * - content: The content for this layout.
+ * - attributes: HTML attributes for the layout <div>.
+ *
+ * @ingroup themeable
+ */
+#}
+{%
+  set classes = [
+    'layout',
+    'layout--fourcol-section',
+  ]
+%}
+{% if content %}
+  <div{{ attributes.addClass(classes) }}>
+
+    {% if content.first %}
+      <div {{ region_attributes.first.addClass('layout__region', 'layout__region--first') }}>
+        {{ content.first }}
+      </div>
+    {% endif %}
+
+    {% if content.second %}
+      <div {{ region_attributes.second.addClass('layout__region', 'layout__region--second') }}>
+        {{ content.second }}
+      </div>
+    {% endif %}
+
+    {% if content.third %}
+      <div {{ region_attributes.third.addClass('layout__region', 'layout__region--third') }}>
+        {{ content.third }}
+      </div>
+    {% endif %}
+
+    {% if content.fourth %}
+      <div {{ region_attributes.fourth.addClass('layout__region', 'layout__region--fourth') }}>
+        {{ content.fourth }}
+      </div>
+    {% endif %}
+
+  </div>
+{% endif %}
diff --git a/core/themes/stable/layouts/threecol_section/layout--threecol-section.html.twig b/core/themes/stable/layouts/threecol_section/layout--threecol-section.html.twig
new file mode 100644
index 0000000000000000000000000000000000000000..1311f28ab2a18bb98e873177804ba5a5dbbb0d42
--- /dev/null
+++ b/core/themes/stable/layouts/threecol_section/layout--threecol-section.html.twig
@@ -0,0 +1,35 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a three-column layout.
+ *
+ * Available variables:
+ * - content: The content for this layout.
+ * - attributes: HTML attributes for the layout <div>.
+ *
+ * @ingroup themeable
+ */
+#}
+{% if content %}
+  <div{{ attributes.addClass(classes) }}>
+
+    {% if content.first %}
+      <div {{ region_attributes.first.addClass('layout__region', 'layout__region--first') }}>
+        {{ content.first }}
+      </div>
+    {% endif %}
+
+    {% if content.second %}
+      <div {{ region_attributes.second.addClass('layout__region', 'layout__region--second') }}>
+        {{ content.second }}
+      </div>
+    {% endif %}
+
+    {% if content.third %}
+      <div {{ region_attributes.third.addClass('layout__region', 'layout__region--third') }}>
+        {{ content.third }}
+      </div>
+    {% endif %}
+
+  </div>
+{% endif %}
diff --git a/core/themes/stable/layouts/threecol_section/threecol_section.css b/core/themes/stable/layouts/threecol_section/threecol_section.css
new file mode 100644
index 0000000000000000000000000000000000000000..49b5578bfc3cab7492a084d98599b394d14b4a11
--- /dev/null
+++ b/core/themes/stable/layouts/threecol_section/threecol_section.css
@@ -0,0 +1,36 @@
+/*
+ * @file
+ * Provides the layout styles for three-column layout section.
+ */
+
+.layout--threecol-section {
+  display: flex;
+  flex-wrap: wrap;
+}
+
+.layout--threecol-section > .layout__region {
+  flex: 0 1 100%;
+}
+
+@media screen and (min-width: 40em) {
+  .layout--threecol-section--25-50-25 > .layout__region--first,
+  .layout--threecol-section--25-50-25 > .layout__region--third,
+  .layout--threecol-section--25-25-50 > .layout__region--first,
+  .layout--threecol-section--25-25-50 > .layout__region--second,
+  .layout--threecol-section--50-25-25 > .layout__region--second,
+  .layout--threecol-section--50-25-25 > .layout__region--third {
+    flex: 0 1 25%;
+  }
+  .layout--threecol-section--25-50-25 > .layout__region--second,
+  .layout--threecol-section--25-25-50 > .layout__region--third,
+  .layout--threecol-section--50-25-25 > .layout__region--first {
+    flex: 0 1 50%;
+  }
+  .layout--threecol-section--33-34-33 > .layout__region--first,
+  .layout--threecol-section--33-34-33 > .layout__region--third {
+    flex: 0 1 33%;
+  }
+  .layout--threecol-section--33-34-33 > .layout__region--second {
+    flex: 0 1 34%;
+  }
+}
diff --git a/core/themes/stable/layouts/twocol_section/layout--twocol-section.html.twig b/core/themes/stable/layouts/twocol_section/layout--twocol-section.html.twig
new file mode 100644
index 0000000000000000000000000000000000000000..a5d1d36376b75a26b074f5739fde80971c220603
--- /dev/null
+++ b/core/themes/stable/layouts/twocol_section/layout--twocol-section.html.twig
@@ -0,0 +1,29 @@
+{#
+/**
+ * @file
+ * Default theme implementation to display a two-column layout.
+ *
+ * Available variables:
+ * - content: The content for this layout.
+ * - attributes: HTML attributes for the layout <div>.
+ *
+ * @ingroup themeable
+ */
+#}
+{% if content %}
+  <div{{ attributes }}>
+
+    {% if content.first %}
+      <div {{ region_attributes.first.addClass('layout__region', 'layout__region--first') }}>
+        {{ content.first }}
+      </div>
+    {% endif %}
+
+    {% if content.second %}
+      <div {{ region_attributes.second.addClass('layout__region', 'layout__region--second') }}>
+        {{ content.second }}
+      </div>
+    {% endif %}
+
+  </div>
+{% endif %}
diff --git a/core/themes/stable/layouts/twocol_section/twocol_section.css b/core/themes/stable/layouts/twocol_section/twocol_section.css
new file mode 100644
index 0000000000000000000000000000000000000000..0d212233508e58adab640bf0531e68ed1a8f811c
--- /dev/null
+++ b/core/themes/stable/layouts/twocol_section/twocol_section.css
@@ -0,0 +1,40 @@
+/*
+ * @file
+ * Provides the layout styles for two-column layout section.
+ */
+
+.layout--twocol-section {
+  display: flex;
+  flex-wrap: wrap;
+}
+
+.layout--twocol-section > .layout__region {
+  flex: 0 1 100%;
+}
+
+@media screen and (min-width: 40em) {
+  .layout--twocol-section.layout--twocol-section--50-50 > .layout__region--first,
+  .layout--twocol-section.layout--twocol-section--50-50 > .layout__region--second {
+    flex: 0 1 50%;
+  }
+
+  .layout--twocol-section.layout--twocol-section--33-67 > .layout__region--first,
+  .layout--twocol-section.layout--twocol-section--67-33 > .layout__region--second {
+    flex: 0 1 33%;
+  }
+
+  .layout--twocol-section.layout--twocol-section--33-67 > .layout__region--second,
+  .layout--twocol-section.layout--twocol-section--67-33 > .layout__region--first {
+    flex: 0 1 67%;
+  }
+
+  .layout--twocol-section.layout--twocol-section--25-75 > .layout__region--first,
+  .layout--twocol-section.layout--twocol-section--75-25 > .layout__region--second {
+    flex: 0 1 25%;
+  }
+
+  .layout--twocol-section.layout--twocol-section--25-75 > .layout__region--second,
+  .layout--twocol-section.layout--twocol-section--75-25 > .layout__region--first {
+    flex: 0 1 75%;
+  }
+}
diff --git a/core/themes/stable/stable.info.yml b/core/themes/stable/stable.info.yml
index 8d774ce2351ad4441db51c67b032b388704e3709..ea26e952277ee68b91ffaa0ea2bbe5386fd34e76 100644
--- a/core/themes/stable/stable.info.yml
+++ b/core/themes/stable/stable.info.yml
@@ -134,6 +134,11 @@ libraries-override:
       theme:
         css/language.admin.css: css/language/language.admin.css
 
+  layout_builder/drupal.layout_builder:
+    css:
+      theme:
+        css/layout-builder.css: css/layout_builder/layout-builder.css
+
   locale/drupal.locale.admin:
     css:
       component: