FEAT-7: AppShell 'Mehr' overflow nav (phone: 4 tabs + Mehr sheet; desktop: all 7) + de.nav.more

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

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;
+  }
+}