diff --git a/gerbil-manager-web/src/components/AppShell.tsx b/gerbil-manager-web/src/components/AppShell.tsx
index 631bd60..8fedf11 100644
--- a/gerbil-manager-web/src/components/AppShell.tsx
+++ b/gerbil-manager-web/src/components/AppShell.tsx
@@ -1,24 +1,40 @@
+import { useState } from 'react'
 import { NavLink, Outlet } from 'react-router-dom'
 import { de } from '../strings/de'
+import './appShell.css'
 
-const navItems = [
+interface NavItem {
+  to: string
+  label: string
+  icon: string
+  end?: boolean
+}
+
+// Primary items are always visible in the phone bottom bar; secondary items
+// move into the "Mehr" sheet on phones and appear inline in the desktop sidebar.
+const PRIMARY: NavItem[] = [
   { to: '/', label: de.nav.home, icon: '🏠', end: true },
-  { to: '/rennmaeuse', label: de.nav.gerbils, icon: '🐭', end: false },
-  { to: '/wuerfe', label: de.nav.litters, icon: '🍼', end: false },
-  { to: '/becken', label: de.nav.enclosures, icon: '🛁', end: false },
-  { to: '/kontakte', label: de.nav.contacts, icon: '📇', end: false },
-  { to: '/genetik', label: de.nav.genetics, icon: '🧬', end: false },
-  // FEAT-7: vorerst 7. Tab; „Mehr“-Overflow für das Smartphone ist mit Kevin
-  // abgestimmt (FEAT-7-Konversation) und ersetzt diesen Eintrag dann.
-  { to: '/statistik', label: de.nav.statistics, icon: '📊', end: false },
+  { to: '/rennmaeuse', label: de.nav.gerbils, icon: '🐭' },
+  { to: '/wuerfe', label: de.nav.litters, icon: '🍼' },
+  { to: '/genetik', label: de.nav.genetics, icon: '🧬' },
 ]
+const SECONDARY: NavItem[] = [
+  { to: '/becken', label: de.nav.enclosures, icon: '🛁' },
+  { to: '/kontakte', label: de.nav.contacts, icon: '📇' },
+  { to: '/statistik', label: de.nav.statistics, icon: '📊' },
+]
+
+const linkClass = ({ isActive }: { isActive: boolean }) =>
+  isActive ? 'nav-link nav-link--active' : 'nav-link'
 
 /**
  * App-Grundgerüst, mobile-first:
- * - Smartphone: Kopfzeile oben, Tab-Leiste unten
- * - Laptop (ab 768px): Seitenleiste links, Inhalt rechts
+ * - Smartphone: Kopfzeile oben, Tab-Leiste unten (4 Haupt-Tabs + „Mehr“).
+ * - Laptop (ab 768px): Seitenleiste links mit allen Einträgen, kein „Mehr“.
  */
 export default function AppShell() {
+  const [moreOpen, setMoreOpen] = useState(false)
+
   return (
     <div className="app-shell">
       <header className="app-header">
@@ -27,21 +43,37 @@ export default function AppShell() {
       </header>
 
       <nav className="app-nav" aria-label={de.nav.mainNavigation}>
-        {navItems.map((item) => (
-          <NavLink
-            key={item.to}
-            to={item.to}
-            end={item.end}
-            className={({ isActive }) =>
-              isActive ? 'nav-link nav-link--active' : 'nav-link'
-            }
+        <div className="nav-primary">
+          {PRIMARY.map((item) => (
+            <NavLink key={item.to} to={item.to} end={item.end} className={linkClass}>
+              <span className="nav-icon" aria-hidden="true">{item.icon}</span>
+              <span className="nav-label">{item.label}</span>
+            </NavLink>
+          ))}
+          <button
+            type="button"
+            className={moreOpen ? 'nav-link nav-more-btn nav-link--active' : 'nav-link nav-more-btn'}
+            aria-expanded={moreOpen}
+            onClick={() => setMoreOpen((o) => !o)}
           >
-            <span className="nav-icon" aria-hidden="true">
-              {item.icon}
-            </span>
-            <span className="nav-label">{item.label}</span>
-          </NavLink>
-        ))}
+            <span className="nav-icon" aria-hidden="true">☰</span>
+            <span className="nav-label">{de.nav.more}</span>
+          </button>
+        </div>
+
+        <div className={moreOpen ? 'nav-secondary nav-secondary--open' : 'nav-secondary'}>
+          {SECONDARY.map((item) => (
+            <NavLink
+              key={item.to}
+              to={item.to}
+              className={linkClass}
+              onClick={() => setMoreOpen(false)}
+            >
+              <span className="nav-icon" aria-hidden="true">{item.icon}</span>
+              <span className="nav-label">{item.label}</span>
+            </NavLink>
+          ))}
+        </div>
       </nav>
 
       <main className="app-main">
diff --git a/gerbil-manager-web/src/components/appShell.css b/gerbil-manager-web/src/components/appShell.css
new file mode 100644
index 0000000..b229cb5
--- /dev/null
+++ b/gerbil-manager-web/src/components/appShell.css
@@ -0,0 +1,67 @@
+/*
+ * AppShell navigation overflow ("Mehr") — co-located with the component to keep
+ * index.css contention-free (shared-file rule). Overrides the base .app-nav
+ * layout from index.css; loaded after it, so these rules win.
+ *
+ * Phone: bottom bar shows 4 primary tabs + a "Mehr" button; the secondary items
+ * live in a sheet that opens ABOVE the bar. Laptop (>=768px): full sidebar, all
+ * items inline, no "Mehr" button.
+ */
+
+/* --- Phone (base) --- */
+.app-nav {
+  /* column-reverse so .nav-secondary (2nd in DOM) renders ABOVE the bar */
+  flex-direction: column-reverse;
+  justify-content: flex-start;
+  padding: 0;
+}
+
+.nav-primary {
+  display: flex;
+  justify-content: space-around;
+}
+
+.nav-more-btn {
+  background: none;
+  border: none;
+  cursor: pointer;
+  font: inherit;
+}
+
+.nav-secondary {
+  display: none;
+  flex-direction: column;
+  background: var(--color-surface);
+  border-bottom: 1px solid var(--color-border);
+  box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.08);
+}
+
+.nav-secondary--open {
+  display: flex;
+}
+
+/* --- Laptop / Tablet (>=768px): full sidebar, no overflow --- */
+@media (min-width: 768px) {
+  .app-nav {
+    flex-direction: column;
+    padding: 1rem 0.5rem;
+  }
+
+  .nav-primary {
+    flex-direction: column;
+    gap: 0.25rem;
+  }
+
+  .nav-more-btn {
+    display: none;
+  }
+
+  .nav-secondary {
+    display: flex;
+    gap: 0.25rem;
+    background: none;
+    border-bottom: none;
+    box-shadow: none;
+    margin-top: 0.25rem;
+  }
+}
diff --git a/gerbil-manager-web/src/strings/de.ts b/gerbil-manager-web/src/strings/de.ts
index 51365a0..edf9f18 100644
--- a/gerbil-manager-web/src/strings/de.ts
+++ b/gerbil-manager-web/src/strings/de.ts
@@ -19,6 +19,8 @@ export const de = {
     contacts: 'Kontakte',
     // FEAT-7 (Kelly): Statistik
     statistics: 'Statistik',
+    // FEAT-7 (Kevin): „Mehr“-Overflow auf dem Smartphone
+    more: 'Mehr',
     openMenu: 'Menü öffnen',
     closeMenu: 'Menü schließen',
     mainNavigation: 'Hauptnavigation',