Enhance login and navigation templates with authentication checks

templates/backoffice/nav.html.twig

@@ -10,6 +10,7 @@
                 aria-label="Toggle navigation">
             <span class="navbar-toggler-icon"></span>
         </button>
+        {% if is_granted('IS_AUTHENTICATED') %}
             <div class="collapse navbar-collapse" id="navbarSupportedContent">
                 <ul class="navbar-nav me-auto mb-2 mb-lg-0">
                     <li class="nav-item">
@@ -24,5 +25,6 @@
                     </li>
                 </ul>
             </div>
+        {% endif %}
     </div>
 </nav>

templates/login/login.html.twig

@@ -9,7 +9,7 @@
         </div>
     {% else %}
         <form method="post">
-            <h1 class="h3 mb-3 font-weight-normal">{{ 'Please sign in'|trans }}</h1>
+            <h1 class="py-2 h3 mb-3 font-weight-normal">{{ 'Please sign in'|trans }}</h1>
             <div class="mb-3">
                 <label for="username" class="form-label">{{ 'Email'|trans }}</label>
                 <input type="email" value="{{ last_username }}" name="_username" id="username" class="form-control"