Footer and Header Includes added

adventskalender/includes/header.html

@@ -0,0 +1,26 @@
+<header class="main-header">
+  <div class="logo">
+    <a href="/">
+      <img src="/shared/images/logo.svg"
+           alt="Bratonien Logo"
+           onerror="this.onerror=null;this.src='/shared/images/logo.png';">
+    </a>
+  </div>
+
+  <div class="header-title">
+    <h1>Adventskalender 2025</h1>
+  </div>
+
+  <nav class="main-nav" id="mainNav">
+    <ul>
+      <li><a href="/">Übersicht</a></li>
+      <li><a href="/2025/">Kalender 2025</a></li>
+      <!-- <li><a href="/2025/">Kalender 2025</a></li> -->
+      <li><a href="https://bratonien.de" target="_blank" rel="noopener noreferrer">bratonien.de</a></li>
+    </ul>
+  </nav>
+
+  <button class="burger" id="burgerBtn" aria-label="Menü öffnen oder schließen">
+    <span></span><span></span><span></span>
+  </button>
+</header>