fix(nav): keep active menu state synced during client-side navigation

src/components/GlassHeader.tsx

@@ -15,12 +15,52 @@ export default function GlassHeader({ lang: propLang }: GlassHeaderProps) {
   const [lang, setLang] = useState<Lang>(propLang || defaultLang);
   const [currentPath, setCurrentPath] = useState("");
 
+  const normalizePath = (path: string) => {
+    const clean = path.split("#")[0].split("?")[0];
+    if (!clean) return "/";
+    if (clean === "/") return "/";
+    return clean.endsWith("/") ? clean.slice(0, -1) : clean;
+  };
+  
   useEffect(() => {
-    setCurrentPath(window.location.pathname);
+    const updatePath = () => setCurrentPath(normalizePath(window.location.pathname));
+    updatePath();
+
+    const syncLang = () => {
       const htmlLang = document.documentElement.lang as Lang;
       if (htmlLang && (!propLang || htmlLang !== lang)) {
         setLang(htmlLang);
       }
+    };
+    syncLang();
+
+    const originalPushState = history.pushState.bind(history);
+    const originalReplaceState = history.replaceState.bind(history);
+
+    history.pushState = function (...args) {
+      originalPushState(...args);
+      window.dispatchEvent(new Event("locationchange"));
+    };
+    history.replaceState = function (...args) {
+      originalReplaceState(...args);
+      window.dispatchEvent(new Event("locationchange"));
+    };
+
+    window.addEventListener("popstate", updatePath);
+    window.addEventListener("locationchange", updatePath);
+    document.addEventListener("astro:after-swap", updatePath as EventListener);
+    document.addEventListener("astro:page-load", updatePath as EventListener);
+    document.addEventListener("astro:page-load", syncLang as EventListener);
+
+    return () => {
+      history.pushState = originalPushState;
+      history.replaceState = originalReplaceState;
+      window.removeEventListener("popstate", updatePath);
+      window.removeEventListener("locationchange", updatePath);
+      document.removeEventListener("astro:after-swap", updatePath as EventListener);
+      document.removeEventListener("astro:page-load", updatePath as EventListener);
+      document.removeEventListener("astro:page-load", syncLang as EventListener);
+    };
   }, [propLang, lang]);
 
   const t = useTranslations(lang);
@@ -48,10 +88,13 @@ export default function GlassHeader({ lang: propLang }: GlassHeaderProps) {
   ];
 
   const isActive = (path: string) => {
-    if (path === '/' || path === '/zh' || path === '/zh/') {
+    const normalizedPath = normalizePath(path);
-      return currentPath === path;
+
+    if (normalizedPath === '/' || normalizedPath === '/zh') {
+      return currentPath === normalizedPath;
     }
-    return currentPath.startsWith(path);
+
+    return currentPath === normalizedPath || currentPath.startsWith(`${normalizedPath}/`);
   };
 
   return (