diff -u b/core/modules/node/lib/Drupal/node/Tests/NodeFieldMultilingualTestCase.php b/core/modules/node/lib/Drupal/node/Tests/NodeFieldMultilingualTestCase.php
--- b/core/modules/node/lib/Drupal/node/Tests/NodeFieldMultilingualTestCase.php
+++ b/core/modules/node/lib/Drupal/node/Tests/NodeFieldMultilingualTestCase.php
@@ -132,7 +132,7 @@
 
     // Check if node body is showed.
     $this->drupalGet('node/' . $node->id());
-     $body = $this->xpath('//article[contains(concat(" ", normalize-space(@class), " "), :node-class)]//div[@class=:content-class]/descendant::p', array(
+     $body = $this->xpath('//article[contains(concat(" ", normalize-space(@class), " "), :node-class)]//div[contains(concat(" ", normalize-space(@class), " "), :content-class)]/descendant::p', array(
       ':node-class' => ' node ',
       ':content-class' => 'node__content',
     ));
diff -u b/core/modules/node/templates/node.html.twig b/core/modules/node/templates/node.html.twig
--- b/core/modules/node/templates/node.html.twig
+++ b/core/modules/node/templates/node.html.twig
@@ -5,14 +5,14 @@
  *
  * Available variables:
  * - node: Full node entity.
- *   - node.id: The node ID.
- *   - node.bundle: The type of the node, for example, "page" or "article".
- *   - node.authorid: The user ID of the node author.
- *   - node.createdtime: Formatted creation date. Preprocess functions can
+ *   - id: The node ID.
+ *   - bundle: The type of the node, for example, "page" or "article".
+ *   - authorid: The user ID of the node author.
+ *   - createdtime: Formatted creation date. Preprocess functions can
  *     reformat it by calling format_date() with the desired parameters on
  *     $variables['node']->getCreatedTime().
- *   - node.promoted: Whether the node is promoted to the front page.
- *   - node.sticky: Whether the node is 'sticky'. Sticky nodes are ordered above
+ *   - promoted: Whether the node is promoted to the front page.
+ *   - sticky: Whether the node is 'sticky'. Sticky nodes are ordered above
  *     other non-sticky nodes in teaser listings
  *   - published: Whether the node is published.
  * - label: The title of the node.
@@ -43,9 +43,9 @@
  *   - node--preview: Whether a node is in preview mode.
  *   The following are controlled through the node publishing options.
  *   - node--promoted: Appears on nodes promoted to the front page.
- *   - node---sticky: Appears on nodes ordered above other non-sticky nodes in
+ *   - node--sticky: Appears on nodes ordered above other non-sticky nodes in
  *     teaser listings.
- *   - node---unpublished: Appears on unpublished nodes visible only to site
+ *   - node--unpublished: Appears on unpublished nodes visible only to site
  *     admins.
  * - title_prefix: Additional output populated by modules, intended to be
  *   displayed in front of the main title tag that appears in the template.
@@ -95,7 +95,7 @@
     </footer>
   {% endif %}
 
-  <div class="node__content{{ content_attributes.class }}"{{ content_attributes|without('class') }}>
+  <div class="node__content {{ content_attributes.class }}"{{ content_attributes|without('class') }}>
     {{ content|without('links') }}
   </div>
 
diff -u b/core/themes/bartik/templates/node.html.twig b/core/themes/bartik/templates/node.html.twig
--- b/core/themes/bartik/templates/node.html.twig
+++ b/core/themes/bartik/templates/node.html.twig
@@ -5,16 +5,16 @@
  *
  * Available variables:
  * - node: Full node entity.
- *   - node.id: The node ID.
- *   - node.bundle: The type of the node, for example, "page" or "article".
- *   - node.authorid: The user ID of the node author.
- *   - node.createdtime: Formatted creation date. Preprocess functions can
+ *   - id: The node ID.
+ *   - bundle: The type of the node, for example, "page" or "article".
+ *   - authorid: The user ID of the node author.
+ *   - createdtime: Formatted creation date. Preprocess functions can
  *     reformat it by calling format_date() with the desired parameters on
  *     $variables['node']->getCreatedTime().
- *   - node.promoted: Whether the node is promoted to the front page.
- *   - node.sticky: Whether the node is 'sticky'. Sticky nodes are ordered above
+ *   - promoted: Whether the node is promoted to the front page.
+ *   - sticky: Whether the node is 'sticky'. Sticky nodes are ordered above
  *     other non-sticky nodes in teaser listings
- *   - node.published: Whether the node is published.
+ *   - published: Whether the node is published.
  * - label: The title of the node.
  * - content: All node items. Use {{ content }} to print them all,
  *   or print a subset such as {{ content.field_example }}. Use