fix layout issues

data/web/templates/base.twig

@@ -117,7 +117,7 @@
 <form action="/" method="post" id="logout"><input type="hidden" name="logout"></form>
 
 {% if ui_texts.ui_announcement_text and ui_texts.ui_announcement_active and not is_root_uri %}
-<div class="container">
+<div class="container mt-4">
   <div class="alert alert-{{ ui_texts.ui_announcement_type }}">{{ ui_texts.ui_announcement_text }}</div>
 </div>
 {% endif %}