fixed w3 validator errors and warnings

theme/templates/base.html

@@ -32,13 +32,13 @@
 	</nav>-->
 	<header>
 		{% block site_header %}
-		<h1><a href="{{ siteurl }}/{{ l }}/" title="{{ t[l].banner.title|e }}" ><img alt="{{ t[l].banner.alt|e }}" src="{{ siteurl }}/{{ theme.static_dir }}/images/banner-logo.png"><span>{{ t[l].banner.prefix|e }}{{ t[l].sitename|e }}{{ t[l].banner.suffix|e }}</span></a></h1>
+		<a href="{{ siteurl }}/{{ l }}/" title="{{ t[l].banner.title|e }}" ><img alt="{{ t[l].banner.alt|e }}" src="{{ siteurl }}/{{ theme.static_dir }}/images/banner-logo.png"><span>{{ t[l].banner.prefix|e }}{{ t[l].sitename|e }}{{ t[l].banner.suffix|e }}</span></a>
 		{% block extra_header %}{% endblock extra_header %}
 		{% endblock site_header %}
 	</header>
 	<div id="sitemenu-container">
 		<label for="show-header-menu" class="show-header-menu">&#9776;</label>
-		<input type="checkbox" id="show-header-menu" role="button">
+		<input type="checkbox" id="show-header-menu" role="button" aria-pressed="true">
 		<label for="show-header-menu" class="show-header-menu-bg"> </label>
 		{{ nav.render_menu(config.menuitems, l) }}
 	</div>
@@ -55,7 +55,7 @@
 		<div>
 			<a href="https://asta.uni-goettingen.de/impressum/datenschutz/">Datenschutz</a>
 			<a href="/fg-website/Impressum.md">Impressum</a>
-		<div>
+		</div>
 		<div>Fachgruppe Informatik Göttingen, 2022.</div>
 		<!-- blablabla datenschutz,impressum etc... -->
 	</footer>