diff --git a/frontend/index.html b/frontend/index.html
index f6070997..0b80095c 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -1,6 +1,7 @@
 <!doctype html>
 <html lang="zh">
   <head>
+    <script>document.documentElement.lang = localStorage.getItem('locale') || 'zh'</script>
     <link rel="preconnect" href="https://fonts.googleapis.com">
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@100..800&family=Noto+Sans+SC:wght@300;400;500;700;800;900&family=Space+Grotesk:wght@300..700&display=swap" rel="stylesheet">
