もう一つ…

resources/views/layouts/site.blade.php

@@ -75,7 +75,8 @@
       </ul>
     </div>
   </nav>
-  <div id="app">
+  <main id="app">
+    <section>
       <div class="container">
         <div class="row" style="padding: 32px 0;">
           <div class="col">
@@ -116,7 +117,8 @@
           </div>
         </div>
       </div>
-  </div>
+    </section>
+  </main>
 
   <!-- Scripts -->
   <script src="{{ asset('js/app.js') }}"></script>