diff --git a/source/layouts/layout.erb b/source/layouts/layout.erb
index bcceb15..3d05788 100644
--- a/source/layouts/layout.erb
+++ b/source/layouts/layout.erb
@@ -81,6 +81,7 @@ under the License.
       <% end %>
     </div>
     <div class="page-wrapper">
+      <div class="dark-box"></div>
       <div class="content">
         <%= yield %>
         <% if current_page.data.includes %>