diff --git a/core/modules/system/templates/page.html.twig b/core/modules/system/templates/page.html.twig
index 88fc563..9cbe89e 100644
--- a/core/modules/system/templates/page.html.twig
+++ b/core/modules/system/templates/page.html.twig
@@ -61,7 +61,7 @@
  * @ingroup themeable
  */
 #}
-<div class="layout-container">
+<div>
 
   <header role="banner">
     {% if logo %}
@@ -71,21 +71,21 @@
     {% endif %}
 
     {% if site_name or site_slogan %}
-      <div class="name-and-slogan">
+      <div>
 
         {# Use h1 when the content title is empty #}
         {% if title %}
-          <strong class="site-name">
+          <strong>
             <a href="{{ front_page }}" title="{{ 'Home'|t }}" rel="home">{{ site_name }}</a>
           </strong>
         {% else %}
-          <h1 class="site-name">
+          <h1>
             <a href="{{ front_page }}" title="{{ 'Home'|t }}" rel="home">{{ site_name }}</a>
           </h1>
         {% endif %}
 
         {% if site_slogan %}
-          <div class="site-slogan">{{ site_slogan }}</div>
+          <div>{{ site_slogan }}</div>
         {% endif %}
       </div>{# ./name-and-slogan #}
     {% endif %}
@@ -105,7 +105,7 @@
   <main role="main">
     <a id="main-content" tabindex="-1"></a>{# link is in html.html.twig #}
 
-    <div class="layout-content">
+    <div>
       {{ page.highlighted }}
 
       {{ title_prefix }}
@@ -117,20 +117,20 @@
       {{ tabs }}
 
       {% if action_links %}
-        <nav class="action-links">{{ action_links }}</nav>
+        <nav>{{ action_links }}</nav>
       {% endif %}
 
       {{ page.content }}
     </div>{# /.layout-content #}
 
     {% if page.sidebar_first %}
-      <aside class="layout-sidebar-first" role="complementary">
+      <aside role="complementary">
         {{ page.sidebar_first }}
       </aside>
     {% endif %}
 
     {% if page.sidebar_second %}
-      <aside class="layout-sidebar-second" role="complementary">
+      <aside role="complementary">
         {{ page.sidebar_second }}
       </aside>
     {% endif %}
diff --git a/core/modules/system/templates/pager.html.twig b/core/modules/system/templates/pager.html.twig
index a7acd5e..8862a92 100644
--- a/core/modules/system/templates/pager.html.twig
+++ b/core/modules/system/templates/pager.html.twig
@@ -32,12 +32,12 @@
  */
 #}
 {% if items %}
-  <nav class="pager" role="navigation" aria-labelledby="pagination-heading">
+  <nav role="navigation" aria-labelledby="pagination-heading">
     <h4 id="pagination-heading" class="visually-hidden">{{ 'Pagination'|t }}</h4>
-    <ul class="pager__items">
+    <ul>
       {# Print first item if we are not on the first page. #}
       {% if items.first %}
-        <li class="pager__item pager__item--first">
+        <li>
           <a href="{{ items.first.href }}" title="{{ 'Go to first page'|t }}"{{ items.first.attributes }}>
             <span class="visually-hidden">{{ 'First page'|t }}</span>
             <span aria-hidden="true">{{ items.first.text|default('« first'|t) }}</span>
@@ -46,7 +46,7 @@
       {% endif %}
       {# Print previous item if we are not on the first page. #}
       {% if items.previous %}
-        <li class="pager__item pager__item--previous">
+        <li>
           <a href="{{ items.previous.href }}" title="{{ 'Go to previous page'|t }}" rel="prev"{{ items.previous.attributes }}>
             <span class="visually-hidden">{{ 'Previous page'|t }}</span>
             <span aria-hidden="true">{{ items.previous.text|default('‹ previous'|t) }}</span>
@@ -55,11 +55,11 @@
       {% endif %}
       {# Add an ellipsis if there are further previous pages. #}
       {% if ellipses.previous %}
-        <li class="pager__item pager__item--ellipsis" role="presentation">&hellip;</li>
+        <li role="presentation">&hellip;</li>
       {% endif %}
       {# Now generate the actual pager piece. #}
       {% for key, item in items.pages %}
-        <li class="pager__item{{ current == key ? ' is-active' : '' }}">
+        <li>
           {% if current == key %}
             {% set title = 'Current page'|t %}
           {% else %}
@@ -75,11 +75,11 @@
       {% endfor %}
       {# Add an ellipsis if there are further next pages. #}
       {% if ellipses.next %}
-        <li class="pager__item pager__item--ellipsis" role="presentation">&hellip;</li>
+        <li role="presentation">&hellip;</li>
       {% endif %}
       {# Print next item if we are not on the last page. #}
       {% if items.next %}
-        <li class="pager__item pager__item--next">
+        <li>
           <a href="{{ items.next.href }}" title="{{ 'Go to next page'|t }}" rel="next"{{ items.next.attributes }}>
             <span class="visually-hidden">{{ 'Next page'|t }}</span>
             <span aria-hidden="true">{{ items.next.text|default('next ›'|t) }}</span>
@@ -88,7 +88,7 @@
       {% endif %}
       {# Print last item if we are not on the last page. #}
       {% if items.last %}
-        <li class="pager__item pager__item--last">
+        <li>
           <a href="{{ items.last.href }}" title="{{ 'Go to last page'|t }}"{{ items.last.attributes }}>
             <span class="visually-hidden">{{ 'Last page'|t }}</span>
             <span aria-hidden="true">{{ items.last.text|default('last »'|t) }}</span>
diff --git a/core/modules/system/templates/progress-bar.html.twig b/core/modules/system/templates/progress-bar.html.twig
index 885a80f..ae5a0ad 100644
--- a/core/modules/system/templates/progress-bar.html.twig
+++ b/core/modules/system/templates/progress-bar.html.twig
@@ -13,11 +13,11 @@
  * @ingroup themeable
  */
 #}
-<div class="progress" data-drupal-progress>
+<div data-drupal-progress>
   {% if label %}
-    <div class="progress__label">{{ label }}</div>
+    <div>{{ label }}</div>
   {% endif %}
-  <div class="progress__track"><div class="progress__bar" style="width: {{ percent }}%"></div></div>
-  <div class="progress__percentage">{{ percent }}%</div>
-  <div class="progress__description">{{ message }}</div>
+  <div><div class="progress__bar" style="width: {{ percent }}%"></div></div>
+  <div>{{ percent }}%</div>
+  <div>{{ message }}</div>
 </div>
diff --git a/core/themes/classy/templates/page.html.twig b/core/themes/classy/templates/page.html.twig
new file mode 100644
index 0000000..88fc563
--- /dev/null
+++ b/core/themes/classy/templates/page.html.twig
@@ -0,0 +1,146 @@
+{#
+/**
+ * @file
+ * Default theme implementation to display a single page.
+ *
+ * The doctype, html, head and body tags are not in this template. Instead they
+ * can be found in the html.html.twig template in this directory.
+ *
+ * Available variables:
+ *
+ * General utility variables:
+ * - base_path: The base URL path of the Drupal installation. Will usually be
+ *   "/" unless you have installed Drupal in a sub-directory.
+ * - is_front: A flag indicating if the current page is the front page.
+ * - logged_in: A flag indicating if the user is registered and signed in.
+ * - is_admin: A flag indicating if the user has permission to access
+ *   administration pages.
+ *
+ * Site identity:
+ * - front_page: The URL of the front page. Use this instead of base_path when
+ *   linking to the front page. This includes the language domain or prefix.
+ * - logo: The url of the logo image, as defined in theme settings.
+ * - site_name: The name of the site. This is empty when displaying the site
+ *   name has been disabled in the theme settings.
+ * - site_slogan: The slogan of the site. This is empty when displaying the site
+ *   slogan has been disabled in theme settings.
+ *
+ * Navigation:
+ * - breadcrumb: The breadcrumb trail for the current page.
+ *
+ * Page content (in order of occurrence in the default page.html.twig):
+ * - title_prefix: Additional output populated by modules, intended to be
+ *   displayed in front of the main title tag that appears in the template.
+ * - title: The page title, for use in the actual content.
+ * - title_suffix: Additional output populated by modules, intended to be
+ *   displayed after the main title tag that appears in the template.
+ * - messages: Status and error messages. Should be displayed prominently.
+ * - tabs: Tabs linking to any sub-pages beneath the current page (e.g., the
+ *   view and edit tabs when displaying a node).
+ * - action_links: Actions local to the page, such as "Add menu" on the menu
+ *   administration interface.
+ * - node: Fully loaded node, if there is an automatically-loaded node
+ *   associated with the page and the node ID is the second argument in the
+ *   page's path (e.g. node/12345 and node/12345/revisions, but not
+ *   comment/reply/12345).
+ *
+ * Regions:
+ * - page.header: Items for the header region.
+ * - page.primary_menu: Items for the primary menu region.
+ * - page.secondary_menu: Items for the secondary menu region.
+ * - page.highlighted: Items for the highlighted content region.
+ * - page.help: Dynamic help text, mostly for admin pages.
+ * - page.content: The main content of the current page.
+ * - page.sidebar_first: Items for the first sidebar.
+ * - page.sidebar_second: Items for the second sidebar.
+ * - page.footer: Items for the footer region.
+ *
+ * @see template_preprocess_page()
+ * @see html.html.twig
+ *
+ * @ingroup themeable
+ */
+#}
+<div class="layout-container">
+
+  <header role="banner">
+    {% if logo %}
+      <a href="{{ front_page }}" title="{{ 'Home'|t }}" rel="home">
+        <img src="{{ logo }}" alt="{{ 'Home'|t }}"/>
+      </a>
+    {% endif %}
+
+    {% if site_name or site_slogan %}
+      <div class="name-and-slogan">
+
+        {# Use h1 when the content title is empty #}
+        {% if title %}
+          <strong class="site-name">
+            <a href="{{ front_page }}" title="{{ 'Home'|t }}" rel="home">{{ site_name }}</a>
+          </strong>
+        {% else %}
+          <h1 class="site-name">
+            <a href="{{ front_page }}" title="{{ 'Home'|t }}" rel="home">{{ site_name }}</a>
+          </h1>
+        {% endif %}
+
+        {% if site_slogan %}
+          <div class="site-slogan">{{ site_slogan }}</div>
+        {% endif %}
+      </div>{# ./name-and-slogan #}
+    {% endif %}
+
+    {{ page.header }}
+  </header>
+
+  {{ page.primary_menu }}
+  {{ page.secondary_menu }}
+
+  {{ breadcrumb }}
+
+  {{ messages }}
+
+  {{ page.help }}
+
+  <main role="main">
+    <a id="main-content" tabindex="-1"></a>{# link is in html.html.twig #}
+
+    <div class="layout-content">
+      {{ page.highlighted }}
+
+      {{ title_prefix }}
+      {% if title %}
+        <h1>{{ title }}</h1>
+      {% endif %}
+      {{ title_suffix }}
+
+      {{ tabs }}
+
+      {% if action_links %}
+        <nav class="action-links">{{ action_links }}</nav>
+      {% endif %}
+
+      {{ page.content }}
+    </div>{# /.layout-content #}
+
+    {% if page.sidebar_first %}
+      <aside class="layout-sidebar-first" role="complementary">
+        {{ page.sidebar_first }}
+      </aside>
+    {% endif %}
+
+    {% if page.sidebar_second %}
+      <aside class="layout-sidebar-second" role="complementary">
+        {{ page.sidebar_second }}
+      </aside>
+    {% endif %}
+
+  </main>
+
+  {% if page.footer %}
+    <footer role="contentinfo">
+      {{ page.footer }}
+    </footer>
+  {% endif %}
+
+</div>{# /.layout-container #}
diff --git a/core/themes/classy/templates/pager.html.twig b/core/themes/classy/templates/pager.html.twig
new file mode 100644
index 0000000..a7acd5e
--- /dev/null
+++ b/core/themes/classy/templates/pager.html.twig
@@ -0,0 +1,100 @@
+{#
+/**
+ * @file
+ * Default theme implementation to display a pager.
+ *
+ * Available variables:
+ * - items: List of pager items.
+ *   The list is keyed by the following elements:
+ *   - first: Item for the first page; not present on the first page of results.
+ *   - previous: Item for the previous page; not present on the first page
+ *     of results.
+ *   - next: Item for the next page; not present on the last page of results.
+ *   - last: Item for the last page; not present on the last page of results.
+ *   - pages: List of pages, keyed by page number.
+ *   Sub-sub elements:
+ *   items.first, items.previous, items.next, items.last, and each item inside
+ *   items.pages contain the following elements:
+ *   - href: URL with appropriate query parameters for the item.
+ *   - attributes: A keyed list of HTML attributes for the item.
+ *   - text: The visible text used for the item link, such as "‹ previous"
+ *     or "next ›".
+ * - current: The page number of the current page.
+ * - ellipses: If there are more pages than the quantity allows, then an
+ *   ellipsis before or after the listed pages may be present.
+ *   - previous: Present if the currently visible list of pages does not start
+ *     at the first page.
+ *   - next: Present if the visible list of pages ends before the last page.
+ *
+ * @see template_preprocess_pager()
+ *
+ * @ingroup themeable
+ */
+#}
+{% if items %}
+  <nav class="pager" role="navigation" aria-labelledby="pagination-heading">
+    <h4 id="pagination-heading" class="visually-hidden">{{ 'Pagination'|t }}</h4>
+    <ul class="pager__items">
+      {# Print first item if we are not on the first page. #}
+      {% if items.first %}
+        <li class="pager__item pager__item--first">
+          <a href="{{ items.first.href }}" title="{{ 'Go to first page'|t }}"{{ items.first.attributes }}>
+            <span class="visually-hidden">{{ 'First page'|t }}</span>
+            <span aria-hidden="true">{{ items.first.text|default('« first'|t) }}</span>
+          </a>
+        </li>
+      {% endif %}
+      {# Print previous item if we are not on the first page. #}
+      {% if items.previous %}
+        <li class="pager__item pager__item--previous">
+          <a href="{{ items.previous.href }}" title="{{ 'Go to previous page'|t }}" rel="prev"{{ items.previous.attributes }}>
+            <span class="visually-hidden">{{ 'Previous page'|t }}</span>
+            <span aria-hidden="true">{{ items.previous.text|default('‹ previous'|t) }}</span>
+          </a>
+        </li>
+      {% endif %}
+      {# Add an ellipsis if there are further previous pages. #}
+      {% if ellipses.previous %}
+        <li class="pager__item pager__item--ellipsis" role="presentation">&hellip;</li>
+      {% endif %}
+      {# Now generate the actual pager piece. #}
+      {% for key, item in items.pages %}
+        <li class="pager__item{{ current == key ? ' is-active' : '' }}">
+          {% if current == key %}
+            {% set title = 'Current page'|t %}
+          {% else %}
+            {% set title = 'Go to page @key'|t({'@key': key}) %}
+          {% endif %}
+          <a href="{{ item.href }}" title="{{ title }}"{{ item.attributes }}>
+            <span class="visually-hidden">
+              {{ current == key ? 'Current page'|t : 'Page'|t }}
+            </span>
+            {{- key -}}
+          </a>
+        </li>
+      {% endfor %}
+      {# Add an ellipsis if there are further next pages. #}
+      {% if ellipses.next %}
+        <li class="pager__item pager__item--ellipsis" role="presentation">&hellip;</li>
+      {% endif %}
+      {# Print next item if we are not on the last page. #}
+      {% if items.next %}
+        <li class="pager__item pager__item--next">
+          <a href="{{ items.next.href }}" title="{{ 'Go to next page'|t }}" rel="next"{{ items.next.attributes }}>
+            <span class="visually-hidden">{{ 'Next page'|t }}</span>
+            <span aria-hidden="true">{{ items.next.text|default('next ›'|t) }}</span>
+          </a>
+        </li>
+      {% endif %}
+      {# Print last item if we are not on the last page. #}
+      {% if items.last %}
+        <li class="pager__item pager__item--last">
+          <a href="{{ items.last.href }}" title="{{ 'Go to last page'|t }}"{{ items.last.attributes }}>
+            <span class="visually-hidden">{{ 'Last page'|t }}</span>
+            <span aria-hidden="true">{{ items.last.text|default('last »'|t) }}</span>
+          </a>
+        </li>
+      {% endif %}
+    </ul>
+  </nav>
+{% endif %}
diff --git a/core/themes/classy/templates/progress-bar.html.twig b/core/themes/classy/templates/progress-bar.html.twig
new file mode 100644
index 0000000..885a80f
--- /dev/null
+++ b/core/themes/classy/templates/progress-bar.html.twig
@@ -0,0 +1,23 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a progress bar.
+ *
+ * Note that the core Batch API uses this only for non-JavaScript batch jobs.
+ *
+ * Available variables:
+ * - label: The label of the working task.
+ * - percent: The percentage of the progress.
+ * - message: A string containing information to be displayed.
+ *
+ * @ingroup themeable
+ */
+#}
+<div class="progress" data-drupal-progress>
+  {% if label %}
+    <div class="progress__label">{{ label }}</div>
+  {% endif %}
+  <div class="progress__track"><div class="progress__bar" style="width: {{ percent }}%"></div></div>
+  <div class="progress__percentage">{{ percent }}%</div>
+  <div class="progress__description">{{ message }}</div>
+</div>