补充主题静态资源与归档模板

assets/css/frontend/nav/nav-fixed-mobile-fallback.css

@@ -0,0 +1,10 @@
+/* ===== nav_fixed mobile fallback ===== */
+/* On mobile, static nav should remain sticky so the hamburger toggle stays accessible */
+@media (max-width: 767px) {
+  .has-static-nav .site-nav--static {
+    position: sticky;
+    top: 0;
+    z-index: 1000;
+  }
+}
+