Light- und Darkmode hinzugefügt

bin/main/static/js/nav.js

@@ -1,4 +1,23 @@
 (function () {
+    // ── Theme-Init (synchron, vor allem anderen) ──────────────────────────────
+    window._applyTheme = function (theme) {
+        document.documentElement.setAttribute('data-theme', theme);
+    };
+    (function () {
+        const saved = localStorage.getItem('xxx-theme');
+        if (saved === 'light' || saved === 'dark') {
+            window._applyTheme(saved);
+        } else {
+            const prefersLight = window.matchMedia('(prefers-color-scheme: light)').matches;
+            window._applyTheme(prefersLight ? 'light' : 'dark');
+        }
+    })();
+    window.matchMedia('(prefers-color-scheme: light)').addEventListener('change', function (e) {
+        if (!localStorage.getItem('xxx-theme')) {
+            window._applyTheme(e.matches ? 'light' : 'dark');
+        }
+    });
+
     const path = window.location.pathname;
     const I = window.IC || function () { return ''; };