diff --git a/agaric/templates/layout/page.html.twig b/agaric/templates/layout/page.html.twig
index 1703759..968138e 100644
--- a/agaric/templates/layout/page.html.twig
+++ b/agaric/templates/layout/page.html.twig
@@ -74,3 +74,80 @@
   {% endblock tabs %}
 </section>
 {% endblock header %}
+
+
+{% block main %}
+{# Main section #}
+{# Only group the main content into one wrapping element if it needs to be
+   separated from a sidebar or two. #}
+{% if page.sidebar_first or page.sidebar_second %}
+<section class="section">
+  <main role="main" class="container">
+{% endif %}
+  <a id="main-content" tabindex="-1"></a>{# link is in html.html.twig #}
+
+    {{ page.highlighted }}
+    {{ page.help }}
+
+    {% block main_content %}
+    {# Set attributes for content. #}
+    {% if not page.content_attributes %}
+    {%
+      set page = page|merge({
+        'content_attributes': create_attribute().addClass([
+          'main-content',
+          'column',
+        ]),
+      })
+    %}
+    {% endif %}
+    {# Main content #}
+    <div{{page.content_attributes}}>
+      {{ page.content }}
+    </div>
+    {% endblock main_content %}
+    {% block sidebar_first %}
+    {# Sidebar first #}
+    {% if page.sidebar_first %}
+    {# Set attributes for content. #}
+      {% if not page.sidebar_first_attributes %}
+      {%
+        set page = page|merge({
+          'sidebar_first_attributes': create_attribute().addClass([
+            'sidebar-first',
+            'column',
+            'is-2',
+          ]),
+        })
+      %}
+      {% endif %}
+      <aside{{page.sidebar_first_attributes|without('role')}} role="complimentary">
+        {{ page.sidebar_first }}
+      </aside>
+    {% endif %}
+    {% endblock sidebar_first %}
+    {% block sidebar_second %}
+    {# Sidebar second #}
+    {% if page.sidebar_second %}
+      {% if not page.sidebar_second_attributes %}
+      {%
+        set page = page|merge({
+          'sidebar_second_attributes': create_attribute().addClass([
+            'sidebar-second',
+            'column',
+            'is-2',
+          ]),
+        })
+      %}
+      {% endif %}
+      <aside{{page.sidebar_second_attributes|without('role')}} role="complimentary">
+        {{ page.sidebar_second }}
+      </aside>
+    {% endif %}
+      {% endblock sidebar_second %}
+
+{% if page.sidebar_first or page.sidebar_second %}
+  </main>
+</section>
+{% endif %}
+{% endblock main %}