Update app.py

app.py

@@ -2336,8 +2336,15 @@ SELECTION_JS = """
         document.body.classList.toggle('dark', dark);
         const container = document.querySelector('.gradio-container');
         if (container) container.classList.toggle('dark', dark);
-        const el = document.getElementById('theme-emoji');
-        if (el) el.textContent = dark ? '☀️' : '🌙';
+        // Sync emoji and checkbox — retry until element is available
+        function syncUI() {
+            const el = document.getElementById('theme-emoji');
+            const cb = document.getElementById('dark-toggle-btn');
+            if (el) el.textContent = dark ? '☀️' : '🌙';
+            if (cb) cb.checked = dark;
+            if (!el || !cb) requestAnimationFrame(syncUI);
+        }
+        syncUI();
     }
     function toggleDark() {
         const url = new URL(window.location);