diff --git a/css/style.css b/css/style.css
index 67cbf33..b2669d7 100644
--- a/css/style.css
+++ b/css/style.css
@@ -16,6 +16,8 @@
 
 html {
   scroll-behavior: smooth;
+  overflow-x: hidden;
+  width: 100%;
 }
 
 * {
@@ -32,6 +34,9 @@ body {
   min-height: 100vh;
   display: flex;
   flex-direction: column;
+  overflow-x: hidden;
+  width: 100%;
+  position: relative;
 }
 
 .container {
@@ -49,6 +54,7 @@ header.site-header {
   position: sticky;
   top: 0;
   z-index: 50;
+  width: 100%;
 }
 
 .nav-wrapper {
@@ -66,6 +72,7 @@ header.site-header {
   display: flex;
   align-items: center;
   gap: 8px;
+  white-space: nowrap;
 }
 
 .logo span {
@@ -91,6 +98,51 @@ nav.main-nav a.active {
   color: var(--text-main);
 }
 
+/* Mobile Hamburger Toggle */
+.mobile-toggle {
+  display: none;
+  background: transparent;
+  border: 1px solid var(--border-color);
+  border-radius: var(--radius-md);
+  cursor: pointer;
+  padding: 8px;
+  width: 44px;
+  height: 44px;
+  flex-direction: column;
+  justify-content: center;
+  align-items: center;
+  gap: 5px;
+  z-index: 100;
+  transition: background 0.2s, border-color 0.2s;
+}
+
+.mobile-toggle:hover, .mobile-toggle:focus-visible {
+  background: rgba(255, 255, 255, 0.08);
+  border-color: var(--accent);
+  outline: none;
+}
+
+.mobile-toggle .bar {
+  width: 22px;
+  height: 2px;
+  background-color: var(--text-main);
+  border-radius: 2px;
+  transition: transform 0.25s ease, opacity 0.25s ease;
+}
+
+.mobile-toggle.open .bar:nth-child(1) {
+  transform: translateY(7px) rotate(45deg);
+}
+
+.mobile-toggle.open .bar:nth-child(2) {
+  opacity: 0;
+  transform: scaleX(0);
+}
+
+.mobile-toggle.open .bar:nth-child(3) {
+  transform: translateY(-7px) rotate(-45deg);
+}
+
 .btn {
   display: inline-flex;
   align-items: center;
@@ -152,6 +204,7 @@ nav.main-nav a.active {
   line-height: 1.15;
   margin-bottom: 20px;
   letter-spacing: -0.02em;
+  overflow-wrap: break-word;
 }
 
 .hero h1 .highlight {
@@ -173,6 +226,7 @@ nav.main-nav a.active {
   padding: 2px 8px;
   border-radius: 4px;
   font-size: 0.95em;
+  word-break: break-all;
 }
 
 .hero-actions {
@@ -208,7 +262,7 @@ section.features, section.steps, section.contact {
 
 .grid-3 {
   display: grid;
-  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
+  grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
   gap: 24px;
 }
 
@@ -376,3 +430,165 @@ footer.site-footer {
 .footer-links a:hover {
   color: var(--text-main);
 }
+
+/* ================= RESPONSIVE MOBILE STYLES ================= */
+@media (max-width: 820px) {
+  .mobile-toggle {
+    display: flex;
+  }
+
+  nav.main-nav {
+    display: none;
+    position: fixed;
+    top: 72px;
+    left: 0;
+    width: 100%;
+    height: calc(100vh - 72px);
+    background: rgba(11, 15, 25, 0.97);
+    backdrop-filter: blur(20px);
+    -webkit-backdrop-filter: blur(20px);
+    border-bottom: 1px solid var(--border-color);
+    flex-direction: column;
+    padding: 24px 20px 40px;
+    gap: 14px;
+    overflow-y: auto;
+    z-index: 90;
+    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.8);
+    align-items: stretch;
+  }
+
+  nav.main-nav.open {
+    display: flex;
+    animation: fadeInNav 0.22s ease forwards;
+  }
+
+  nav.main-nav a {
+    font-size: 1.1rem;
+    padding: 12px 14px;
+    border-radius: var(--radius-md);
+    display: block;
+    text-align: left;
+    border: 1px solid transparent;
+  }
+
+  nav.main-nav a:hover,
+  nav.main-nav a.active {
+    background: rgba(56, 189, 248, 0.12);
+    border-color: rgba(56, 189, 248, 0.3);
+  }
+
+  nav.main-nav .btn {
+    margin-top: 8px;
+    width: 100%;
+    text-align: center;
+    padding: 12px;
+    font-size: 1rem;
+  }
+
+  .container {
+    padding: 0 16px;
+  }
+
+  .hero {
+    padding: 48px 0 32px;
+  }
+
+  .hero-badge {
+    font-size: 0.78rem;
+    padding: 5px 12px;
+  }
+
+  .hero h1 {
+    font-size: 1.95rem;
+  }
+
+  .hero p {
+    font-size: 1rem;
+    margin-bottom: 28px;
+  }
+
+  .hero-actions {
+    flex-direction: column;
+    gap: 12px;
+  }
+
+  .hero-actions .btn {
+    width: 100%;
+  }
+
+  .features {
+    padding: 40px 0 60px;
+  }
+
+  .section-header {
+    margin-bottom: 32px;
+  }
+
+  .section-header h2 {
+    font-size: 1.6rem;
+  }
+
+  .grid-3 {
+    grid-template-columns: 1fr;
+    gap: 16px;
+  }
+
+  .card {
+    padding: 22px 18px;
+  }
+
+  .steps {
+    padding: 40px 0 60px;
+  }
+
+  .contact-cta {
+    padding: 50px 0;
+  }
+
+  .cta-box {
+    padding: 30px 18px;
+  }
+
+  .cta-box h2 {
+    font-size: 1.5rem;
+  }
+
+  .cta-box p {
+    font-size: 0.95rem;
+  }
+
+  .content-section {
+    padding: 36px 0;
+  }
+
+  .content-box {
+    padding: 22px 16px;
+  }
+
+  .content-box h1 {
+    font-size: 1.7rem;
+  }
+
+  .footer-content {
+    flex-direction: column;
+    text-align: center;
+    gap: 16px;
+  }
+
+  .footer-links {
+    justify-content: center;
+    flex-wrap: wrap;
+    gap: 16px;
+  }
+}
+
+@keyframes fadeInNav {
+  from {
+    opacity: 0;
+    transform: translateY(-8px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
diff --git a/datenschutz.html b/datenschutz.html
index 168b298..f082964 100644
--- a/datenschutz.html
+++ b/datenschutz.html
@@ -15,11 +15,19 @@
       <a href="index.html" class="logo">
         🥨 <span>Waiswuaschd</span>.de
       </a>
-      <nav class="main-nav">
+      <button class="mobile-toggle" aria-label="Menü öffnen" id="mobileMenuBtn" aria-expanded="false">
+        <span class="bar"></span>
+        <span class="bar"></span>
+        <span class="bar"></span>
+      </button>
+      <nav class="main-nav" id="mainNav">
         <a href="index.html">Startseite</a>
+        <a href="index.html#features">Funktionen</a>
+        <a href="index.html#schritte">So geht's</a>
+        <a href="index.html#kontakt">Portal anfragen</a>
         <a href="impressum.html">Impressum</a>
         <a href="datenschutz.html" class="active">Datenschutz</a>
-        <a href="https://demo.dev.waiswuaschd.de" class="btn btn-outline">Zum Portal</a>
+        <a href="https://demo.dev.waiswuaschd.de" class="btn btn-outline" target="_blank" rel="noopener">Live-Demo (Schmankerl)</a>
       </nav>
     </div>
   </header>
@@ -84,7 +92,7 @@
   <!-- Footer -->
   <footer class="site-footer">
     <div class="container footer-content">
-      <p>&copy; 2026 Waiswuaschd.de</p>
+      <p>&copy; 2026 Waiswuaschd.de – Die Brotzeit-Plattform für Teams.</p>
       <div class="footer-links">
         <a href="index.html">Startseite</a>
         <a href="impressum.html">Impressum</a>
@@ -93,5 +101,26 @@
     </div>
   </footer>
 
+  <script>
+    const mobileBtn = document.getElementById('mobileMenuBtn');
+    const mainNav = document.getElementById('mainNav');
+    if (mobileBtn && mainNav) {
+      mobileBtn.addEventListener('click', () => {
+        const isOpen = mainNav.classList.toggle('open');
+        mobileBtn.classList.toggle('open', isOpen);
+        mobileBtn.setAttribute('aria-expanded', isOpen);
+        document.body.style.overflow = isOpen ? 'hidden' : '';
+      });
+      mainNav.querySelectorAll('a').forEach(link => {
+        link.addEventListener('click', () => {
+          mainNav.classList.remove('open');
+          mobileBtn.classList.remove('open');
+          mobileBtn.setAttribute('aria-expanded', 'false');
+          document.body.style.overflow = '';
+        });
+      });
+    }
+  </script>
+
 </body>
 </html>
diff --git a/impressum.html b/impressum.html
index be1d44f..af41744 100644
--- a/impressum.html
+++ b/impressum.html
@@ -15,11 +15,19 @@
       <a href="index.html" class="logo">
         🥨 <span>Waiswuaschd</span>.de
       </a>
-      <nav class="main-nav">
+      <button class="mobile-toggle" aria-label="Menü öffnen" id="mobileMenuBtn" aria-expanded="false">
+        <span class="bar"></span>
+        <span class="bar"></span>
+        <span class="bar"></span>
+      </button>
+      <nav class="main-nav" id="mainNav">
         <a href="index.html">Startseite</a>
+        <a href="index.html#features">Funktionen</a>
+        <a href="index.html#schritte">So geht's</a>
+        <a href="index.html#kontakt">Portal anfragen</a>
         <a href="impressum.html" class="active">Impressum</a>
         <a href="datenschutz.html">Datenschutz</a>
-        <a href="https://demo.dev.waiswuaschd.de" class="btn btn-outline">Zum Portal</a>
+        <a href="https://demo.dev.waiswuaschd.de" class="btn btn-outline" target="_blank" rel="noopener">Live-Demo (Schmankerl)</a>
       </nav>
     </div>
   </header>
@@ -66,7 +74,7 @@
   <!-- Footer -->
   <footer class="site-footer">
     <div class="container footer-content">
-      <p>&copy; 2026 Waiswuaschd.de</p>
+      <p>&copy; 2026 Waiswuaschd.de – Die Brotzeit-Plattform für Teams.</p>
       <div class="footer-links">
         <a href="index.html">Startseite</a>
         <a href="impressum.html">Impressum</a>
@@ -75,5 +83,26 @@
     </div>
   </footer>
 
+  <script>
+    const mobileBtn = document.getElementById('mobileMenuBtn');
+    const mainNav = document.getElementById('mainNav');
+    if (mobileBtn && mainNav) {
+      mobileBtn.addEventListener('click', () => {
+        const isOpen = mainNav.classList.toggle('open');
+        mobileBtn.classList.toggle('open', isOpen);
+        mobileBtn.setAttribute('aria-expanded', isOpen);
+        document.body.style.overflow = isOpen ? 'hidden' : '';
+      });
+      mainNav.querySelectorAll('a').forEach(link => {
+        link.addEventListener('click', () => {
+          mainNav.classList.remove('open');
+          mobileBtn.classList.remove('open');
+          mobileBtn.setAttribute('aria-expanded', 'false');
+          document.body.style.overflow = '';
+        });
+      });
+    }
+  </script>
+
 </body>
 </html>
diff --git a/index.html b/index.html
index 9a0db4e..88aa6fd 100644
--- a/index.html
+++ b/index.html
@@ -16,7 +16,12 @@
       <a href="index.html" class="logo">
         🥨 <span>Waiswuaschd</span>.de
       </a>
-      <nav class="main-nav">
+      <button class="mobile-toggle" aria-label="Menü öffnen" id="mobileMenuBtn" aria-expanded="false">
+        <span class="bar"></span>
+        <span class="bar"></span>
+        <span class="bar"></span>
+      </button>
+      <nav class="main-nav" id="mainNav">
         <a href="index.html" class="active">Startseite</a>
         <a href="#features">Funktionen</a>
         <a href="#schritte">So geht's</a>
@@ -155,5 +160,26 @@
     </div>
   </footer>
 
+  <script>
+    const mobileBtn = document.getElementById('mobileMenuBtn');
+    const mainNav = document.getElementById('mainNav');
+    if (mobileBtn && mainNav) {
+      mobileBtn.addEventListener('click', () => {
+        const isOpen = mainNav.classList.toggle('open');
+        mobileBtn.classList.toggle('open', isOpen);
+        mobileBtn.setAttribute('aria-expanded', isOpen);
+        document.body.style.overflow = isOpen ? 'hidden' : '';
+      });
+      mainNav.querySelectorAll('a').forEach(link => {
+        link.addEventListener('click', () => {
+          mainNav.classList.remove('open');
+          mobileBtn.classList.remove('open');
+          mobileBtn.setAttribute('aria-expanded', 'false');
+          document.body.style.overflow = '';
+        });
+      });
+    }
+  </script>
+
 </body>
 </html>