diff --git a/src/i18n/index.ts b/src/i18n/index.ts
index eda3632..62a75e5 100644
--- a/src/i18n/index.ts
+++ b/src/i18n/index.ts
@@ -12,12 +12,14 @@ export function getCopy(lang: string | undefined): SiteCopy {
   return copies[DEFAULT_LANG];
 }
 
-/** Astro `getStaticPaths`：为四种语言各生成一页 */
+/** Astro `getStaticPaths`：默认语言生成无前缀路径，其他语言带前缀 */
 export function langStaticPaths() {
-  return LANGS.map((lang) => ({ params: { lang } }));
+  return LANGS.map((lang) => ({
+    params: { lang: lang === DEFAULT_LANG ? undefined : lang },
+  }));
 }
 
 export type { Lang } from './locales';
 export type { SiteCopy } from './types';
-export { LANGS, DEFAULT_LANG, htmlLang, langLabels, hrefFor, isLang } from './locales';
+export { LANGS, DEFAULT_LANG, htmlLang, langLabels, hrefFor, isLang, resolveLang } from './locales';
 export type { RouteKey } from './locales';
diff --git a/src/i18n/locales.ts b/src/i18n/locales.ts
index 079bf36..3316ab1 100644
--- a/src/i18n/locales.ts
+++ b/src/i18n/locales.ts
@@ -26,6 +26,12 @@ export function isLang(value: string | undefined): value is Lang {
 export type RouteKey = '' | 'teaching-philosophy' | 'curriculum' | 'faculty' | 'about';
 
 export function hrefFor(lang: Lang, segment: RouteKey): string {
-  if (!segment) return `/${lang}`;
-  return `/${lang}/${segment}`;
+  const prefix = lang === DEFAULT_LANG ? '' : `/${lang}`;
+  if (!segment) return prefix || '/';
+  return `${prefix}/${segment}`;
+}
+
+/** 从 [...lang] rest 参数解析语言，undefined 时返回默认语言 */
+export function resolveLang(param: string | undefined): Lang {
+  return isLang(param) ? param : DEFAULT_LANG;
 }
diff --git a/src/pages/[lang]/about.astro b/src/pages/[...lang]/about.astro
similarity index 94%
rename from src/pages/[lang]/about.astro
rename to src/pages/[...lang]/about.astro
index 09bf8b0..bd1f46f 100644
--- a/src/pages/[lang]/about.astro
+++ b/src/pages/[...lang]/about.astro
@@ -1,14 +1,13 @@
 ---
 import BaseLayout from '../../layouts/BaseLayout.astro';
-import { getCopy, langStaticPaths, type Lang } from '../../i18n';
+import { getCopy, langStaticPaths, resolveLang } from '../../i18n';
 
 export function getStaticPaths() {
   return langStaticPaths();
 }
 
-const { lang } = Astro.params;
-const L = getCopy(lang);
-const locale = lang as Lang;
+const locale = resolveLang(Astro.params.lang);
+const L = getCopy(locale);
 ---
 
 <BaseLayout
diff --git a/src/pages/[lang]/curriculum.astro b/src/pages/[...lang]/curriculum.astro
similarity index 93%
rename from src/pages/[lang]/curriculum.astro
rename to src/pages/[...lang]/curriculum.astro
index ed6a4e6..8dd037d 100644
--- a/src/pages/[lang]/curriculum.astro
+++ b/src/pages/[...lang]/curriculum.astro
@@ -1,14 +1,13 @@
 ---
 import BaseLayout from '../../layouts/BaseLayout.astro';
-import { getCopy, langStaticPaths, type Lang } from '../../i18n';
+import { getCopy, langStaticPaths, resolveLang } from '../../i18n';
 
 export function getStaticPaths() {
   return langStaticPaths();
 }
 
-const { lang } = Astro.params;
-const L = getCopy(lang);
-const locale = lang as Lang;
+const locale = resolveLang(Astro.params.lang);
+const L = getCopy(locale);
 ---
 
 <BaseLayout
diff --git a/src/pages/[lang]/faculty.astro b/src/pages/[...lang]/faculty.astro
similarity index 96%
rename from src/pages/[lang]/faculty.astro
rename to src/pages/[...lang]/faculty.astro
index 4ab3be5..ed91970 100644
--- a/src/pages/[lang]/faculty.astro
+++ b/src/pages/[...lang]/faculty.astro
@@ -1,15 +1,14 @@
 ---
 import BaseLayout from '../../layouts/BaseLayout.astro';
 import { Icon } from 'astro-icon/components';
-import { getCopy, hrefFor, langStaticPaths, type Lang } from '../../i18n';
+import { getCopy, hrefFor, langStaticPaths, resolveLang } from '../../i18n';
 
 export function getStaticPaths() {
   return langStaticPaths();
 }
 
-const { lang } = Astro.params;
-const L = getCopy(lang);
-const locale = lang as Lang;
+const locale = resolveLang(Astro.params.lang);
+const L = getCopy(locale);
 ---
 
 <BaseLayout
diff --git a/src/pages/[lang]/index.astro b/src/pages/[...lang]/index.astro
similarity index 96%
rename from src/pages/[lang]/index.astro
rename to src/pages/[...lang]/index.astro
index e44b1cb..92372c5 100644
--- a/src/pages/[lang]/index.astro
+++ b/src/pages/[...lang]/index.astro
@@ -1,15 +1,14 @@
 ---
 import BaseLayout from '../../layouts/BaseLayout.astro';
 import { Icon } from 'astro-icon/components';
-import { getCopy, hrefFor, langStaticPaths, type Lang } from '../../i18n';
+import { getCopy, hrefFor, langStaticPaths, resolveLang } from '../../i18n';
 
 export function getStaticPaths() {
   return langStaticPaths();
 }
 
-const { lang } = Astro.params;
-const L = getCopy(lang);
-const locale = lang as Lang;
+const locale = resolveLang(Astro.params.lang);
+const L = getCopy(locale);
 ---
 
 <BaseLayout
diff --git a/src/pages/[lang]/teaching-philosophy.astro b/src/pages/[...lang]/teaching-philosophy.astro
similarity index 96%
rename from src/pages/[lang]/teaching-philosophy.astro
rename to src/pages/[...lang]/teaching-philosophy.astro
index c73b1e4..06c4de1 100644
--- a/src/pages/[lang]/teaching-philosophy.astro
+++ b/src/pages/[...lang]/teaching-philosophy.astro
@@ -1,14 +1,13 @@
 ---
 import BaseLayout from '../../layouts/BaseLayout.astro';
-import { getCopy, langStaticPaths, type Lang } from '../../i18n';
+import { getCopy, langStaticPaths, resolveLang } from '../../i18n';
 
 export function getStaticPaths() {
   return langStaticPaths();
 }
 
-const { lang } = Astro.params;
-const L = getCopy(lang);
-const locale = lang as Lang;
+const locale = resolveLang(Astro.params.lang);
+const L = getCopy(locale);
 ---
 
 <BaseLayout
diff --git a/src/pages/index.astro b/src/pages/index.astro
deleted file mode 100644
index ff8f1bc..0000000
--- a/src/pages/index.astro
+++ /dev/null
@@ -1,30 +0,0 @@
----
-/**
- * 根路径立即跳转默认语言。不用 Astro.redirect，静态构建否则会生成 2 秒 meta refresh。
- */
-import { DEFAULT_LANG } from '../i18n';
-
-const target = `/${DEFAULT_LANG}`;
----
-
-<!DOCTYPE html>
-<html lang="zh-CN">
-  <head>
-    <meta charset="UTF-8" />
-    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta http-equiv="refresh" content={`0;url=${target}`} />
-    <link rel="canonical" href={target} />
-    <meta name="robots" content="noindex" />
-    <title>Redirecting…</title>
-    <script is:inline define:vars={{ target }}>
-      location.replace(target);
-    </script>
-  </head>
-  <body
-    style="margin:0;font-family:system-ui,sans-serif;display:grid;place-items:center;min-height:100vh;background:#fffdfb;color:#444"
-  >
-    <p style="margin:0;font-size:14px">
-      <a href={target} style="color:#4b76eb">继续前往首页 →</a>
-    </p>
-  </body>
-</html>