non ai theme

src/components/Topbar.tsx

@@ -9,13 +9,33 @@ type TopbarProps = {
 
 /** App theme is a data attribute on <html>; tokens.css defines both palettes. */
 function useTheme() {
-  const [theme, setTheme] = useState<'dark' | 'light'>(() =>
-    localStorage.getItem('ns-theme') === 'light' ? 'light' : 'dark',
-  )
+  const [theme, setTheme] = useState<'dark' | 'light'>(() => {
+    const saved = typeof window !== 'undefined' ? localStorage.getItem('ns-theme') : null
+    const initial = saved === 'light' ? 'light' : 'dark'
+    if (typeof document !== 'undefined') {
+      document.documentElement.dataset.theme = initial
+      if (initial === 'dark') {
+        document.documentElement.classList.add('dark')
+        document.documentElement.classList.remove('light')
+      } else {
+        document.documentElement.classList.add('light')
+        document.documentElement.classList.remove('dark')
+      }
+    }
+    return initial
+  })
+
   const toggle = () => {
     const next = theme === 'dark' ? 'light' : 'dark'
     setTheme(next)
     document.documentElement.dataset.theme = next
+    if (next === 'dark') {
+      document.documentElement.classList.add('dark')
+      document.documentElement.classList.remove('light')
+    } else {
+      document.documentElement.classList.add('light')
+      document.documentElement.classList.remove('dark')
+    }
     localStorage.setItem('ns-theme', next)
   }
   return { theme, toggle }