diff --git a/app/generation-preview/page.tsx b/app/generation-preview/page.tsx
index b63b4eb69..936cfe5c6 100644
--- a/app/generation-preview/page.tsx
+++ b/app/generation-preview/page.tsx
@@ -278,15 +278,11 @@ function GenerationPreviewContent() {
         // Truncation warnings
         const warnings: string[] = [];
         if ((parseResult.data.text as string).length > MAX_PDF_CONTENT_CHARS) {
-          warnings.push(
-            t('generation.textTruncated').replace('{n}', String(MAX_PDF_CONTENT_CHARS)),
-          );
+          warnings.push(t('generation.textTruncated', { n: MAX_PDF_CONTENT_CHARS }));
         }
         if (images.length > MAX_VISION_IMAGES) {
           warnings.push(
-            t('generation.imageTruncated')
-              .replace('{total}', String(images.length))
-              .replace('{max}', String(MAX_VISION_IMAGES)),
+            t('generation.imageTruncated', { total: images.length, max: MAX_VISION_IMAGES }),
           );
         }
         if (warnings.length > 0) {
diff --git a/app/page.tsx b/app/page.tsx
index c0da47614..1799ea97e 100644
--- a/app/page.tsx
+++ b/app/page.tsx
@@ -20,6 +20,7 @@ import {
   ChevronUp,
 } from 'lucide-react';
 import { useI18n } from '@/lib/hooks/use-i18n';
+import { LanguageSwitcher } from '@/components/language-switcher';
 import { createLogger } from '@/lib/logger';
 import { Button } from '@/components/ui/button';
 import { Textarea as UITextarea } from '@/components/ui/textarea';
@@ -69,7 +70,7 @@ const initialFormState: FormState = {
 };
 
 function HomePage() {
-  const { t, locale, setLocale } = useI18n();
+  const { t } = useI18n();
   const { theme, setTheme } = useTheme();
   const router = useRouter();
   const [form, setForm] = useState<FormState>(initialFormState);
@@ -124,7 +125,6 @@ function HomePage() {
     }
   }
 
-  const [languageOpen, setLanguageOpen] = useState(false);
   const [themeOpen, setThemeOpen] = useState(false);
   const [error, setError] = useState<string | null>(null);
   const [classrooms, setClassrooms] = useState<StageListItem[]>([]);
@@ -135,16 +135,15 @@ function HomePage() {
 
   // Close dropdowns when clicking outside
   useEffect(() => {
-    if (!languageOpen && !themeOpen) return;
+    if (!themeOpen) return;
     const handleClickOutside = (e: MouseEvent) => {
       if (toolbarRef.current && !toolbarRef.current.contains(e.target as Node)) {
-        setLanguageOpen(false);
         setThemeOpen(false);
       }
     };
     document.addEventListener('mousedown', handleClickOutside);
     return () => document.removeEventListener('mousedown', handleClickOutside);
-  }, [languageOpen, themeOpen]);
+  }, [themeOpen]);
 
   const loadClassrooms = async () => {
     try {
@@ -338,47 +337,7 @@ function HomePage() {
         className="fixed top-4 right-4 z-50 flex items-center gap-1 bg-white/60 dark:bg-gray-800/60 backdrop-blur-md px-2 py-1.5 rounded-full border border-gray-100/50 dark:border-gray-700/50 shadow-sm"
       >
         {/* Language Selector */}
-        <div className="relative">
-          <button
-            onClick={() => {
-              setLanguageOpen(!languageOpen);
-              setThemeOpen(false);
-            }}
-            className="flex items-center gap-1 px-3 py-1.5 rounded-full text-xs font-bold text-gray-500 dark:text-gray-400 hover:bg-white dark:hover:bg-gray-700 hover:text-gray-800 dark:hover:text-gray-200 hover:shadow-sm transition-all"
-          >
-            {locale === 'zh-CN' ? 'CN' : 'EN'}
-          </button>
-          {languageOpen && (
-            <div className="absolute top-full mt-2 right-0 bg-white dark:bg-gray-800 border border-gray-200 dark:border-gray-700 rounded-lg shadow-lg overflow-hidden z-50 min-w-[120px]">
-              <button
-                onClick={() => {
-                  setLocale('zh-CN');
-                  setLanguageOpen(false);
-                }}
-                className={cn(
-                  'w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors',
-                  locale === 'zh-CN' &&
-                    'bg-purple-50 dark:bg-purple-900/20 text-purple-600 dark:text-purple-400',
-                )}
-              >
-                简体中文
-              </button>
-              <button
-                onClick={() => {
-                  setLocale('en-US');
-                  setLanguageOpen(false);
-                }}
-                className={cn(
-                  'w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors',
-                  locale === 'en-US' &&
-                    'bg-purple-50 dark:bg-purple-900/20 text-purple-600 dark:text-purple-400',
-                )}
-              >
-                English
-              </button>
-            </div>
-          )}
-        </div>
+        <LanguageSwitcher onOpen={() => setThemeOpen(false)} />
 
         <div className="w-[1px] h-4 bg-gray-200 dark:bg-gray-700" />
 
@@ -387,7 +346,6 @@ function HomePage() {
           <button
             onClick={() => {
               setThemeOpen(!themeOpen);
-              setLanguageOpen(false);
             }}
             className="p-2 rounded-full text-gray-400 dark:text-gray-500 hover:bg-white dark:hover:bg-gray-700 hover:text-gray-800 dark:hover:text-gray-200 hover:shadow-sm transition-all"
           >
@@ -797,13 +755,8 @@ function GreetingBar() {
             <Tooltip>
               <TooltipTrigger asChild>
                 <span className="leading-none select-none flex items-center gap-1">
-                  <span>
-                    <span className="text-xs text-muted-foreground/60 group-hover:text-muted-foreground transition-colors">
-                      {t('home.greeting')}
-                    </span>
-                    <span className="text-[13px] font-semibold text-foreground/85 group-hover:text-foreground transition-colors">
-                      {displayName}
-                    </span>
+                  <span className="text-[13px] font-semibold text-foreground/85 group-hover:text-foreground transition-colors">
+                    {t('home.greetingWithName', { name: displayName })}
                   </span>
                   <ChevronDown className="size-3 text-muted-foreground/30 group-hover:text-muted-foreground/60 transition-colors shrink-0" />
                 </span>
diff --git a/components/chat/lecture-notes-view.tsx b/components/chat/lecture-notes-view.tsx
index 2669a1afb..309283af8 100644
--- a/components/chat/lecture-notes-view.tsx
+++ b/components/chat/lecture-notes-view.tsx
@@ -67,7 +67,7 @@ export function LectureNotesView({ notes, currentSceneId }: LectureNotesViewProp
       {notes.map((note, index) => {
         const isCurrent = note.sceneId === currentSceneId;
         const pageNum = index + 1;
-        const pageLabel = t('chat.lectureNotes.pageLabel').replace('{n}', String(pageNum));
+        const pageLabel = t('chat.lectureNotes.pageLabel', { n: pageNum });
 
         return (
           <div
diff --git a/components/header.tsx b/components/header.tsx
index 5a61ec96f..84c0c3e99 100644
--- a/components/header.tsx
+++ b/components/header.tsx
@@ -13,6 +13,7 @@ import {
 } from 'lucide-react';
 import { useI18n } from '@/lib/hooks/use-i18n';
 import { useTheme } from '@/lib/hooks/use-theme';
+import { LanguageSwitcher } from './language-switcher';
 import { useState, useEffect, useRef, useCallback } from 'react';
 import { useRouter } from 'next/navigation';
 import { SettingsDialog } from './settings';
@@ -26,11 +27,10 @@ interface HeaderProps {
 }
 
 export function Header({ currentSceneTitle }: HeaderProps) {
-  const { t, locale, setLocale } = useI18n();
+  const { t } = useI18n();
   const { theme, setTheme } = useTheme();
   const router = useRouter();
   const [settingsOpen, setSettingsOpen] = useState(false);
-  const [languageOpen, setLanguageOpen] = useState(false);
   const [themeOpen, setThemeOpen] = useState(false);
 
   // Export
@@ -48,15 +48,11 @@ export function Header({ currentSceneTitle }: HeaderProps) {
     failedOutlines.length === 0 &&
     Object.values(mediaTasks).every((task) => task.status === 'done' || task.status === 'failed');
 
-  const languageRef = useRef<HTMLDivElement>(null);
   const themeRef = useRef<HTMLDivElement>(null);
 
   // Close dropdown when clicking outside
   const handleClickOutside = useCallback(
     (e: MouseEvent) => {
-      if (languageOpen && languageRef.current && !languageRef.current.contains(e.target as Node)) {
-        setLanguageOpen(false);
-      }
       if (themeOpen && themeRef.current && !themeRef.current.contains(e.target as Node)) {
         setThemeOpen(false);
       }
@@ -64,15 +60,15 @@ export function Header({ currentSceneTitle }: HeaderProps) {
         setExportMenuOpen(false);
       }
     },
-    [languageOpen, themeOpen, exportMenuOpen],
+    [themeOpen, exportMenuOpen],
   );
 
   useEffect(() => {
-    if (languageOpen || themeOpen || exportMenuOpen) {
+    if (themeOpen || exportMenuOpen) {
       document.addEventListener('mousedown', handleClickOutside);
       return () => document.removeEventListener('mousedown', handleClickOutside);
     }
-  }, [languageOpen, themeOpen, exportMenuOpen, handleClickOutside]);
+  }, [themeOpen, exportMenuOpen, handleClickOutside]);
 
   return (
     <>
@@ -100,47 +96,7 @@ export function Header({ currentSceneTitle }: HeaderProps) {
 
         <div className="flex items-center gap-4 bg-white/60 dark:bg-gray-800/60 backdrop-blur-md px-2 py-1.5 rounded-full border border-gray-100/50 dark:border-gray-700/50 shadow-sm shrink-0">
           {/* Language Selector */}
-          <div className="relative" ref={languageRef}>
-            <button
-              onClick={() => {
-                setLanguageOpen(!languageOpen);
-                setThemeOpen(false);
-              }}
-              className="flex items-center gap-1 px-3 py-1.5 rounded-full text-xs font-bold text-gray-500 dark:text-gray-400 hover:bg-white dark:hover:bg-gray-700 hover:text-gray-800 dark:hover:text-gray-200 hover:shadow-sm transition-all"
-            >
-              {locale === 'zh-CN' ? 'CN' : 'EN'}
-            </button>
-            {languageOpen && (
-              <div className="absolute top-full mt-2 right-0 bg-white dark:bg-gray-800 border border-gray-200 dark:border-gray-700 rounded-lg shadow-lg overflow-hidden z-50 min-w-[120px]">
-                <button
-                  onClick={() => {
-                    setLocale('zh-CN');
-                    setLanguageOpen(false);
-                  }}
-                  className={cn(
-                    'w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors',
-                    locale === 'zh-CN' &&
-                      'bg-purple-50 dark:bg-purple-900/20 text-purple-600 dark:text-purple-400',
-                  )}
-                >
-                  简体中文
-                </button>
-                <button
-                  onClick={() => {
-                    setLocale('en-US');
-                    setLanguageOpen(false);
-                  }}
-                  className={cn(
-                    'w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors',
-                    locale === 'en-US' &&
-                      'bg-purple-50 dark:bg-purple-900/20 text-purple-600 dark:text-purple-400',
-                  )}
-                >
-                  English
-                </button>
-              </div>
-            )}
-          </div>
+          <LanguageSwitcher onOpen={() => setThemeOpen(false)} />
 
           <div className="w-[1px] h-4 bg-gray-200 dark:bg-gray-700" />
 
@@ -149,7 +105,6 @@ export function Header({ currentSceneTitle }: HeaderProps) {
             <button
               onClick={() => {
                 setThemeOpen(!themeOpen);
-                setLanguageOpen(false);
               }}
               className="p-2 rounded-full text-gray-400 dark:text-gray-500 hover:bg-white dark:hover:bg-gray-700 hover:text-gray-800 dark:hover:text-gray-200 hover:shadow-sm transition-all group"
             >
diff --git a/components/language-switcher.tsx b/components/language-switcher.tsx
new file mode 100644
index 000000000..684397ad0
--- /dev/null
+++ b/components/language-switcher.tsx
@@ -0,0 +1,64 @@
+'use client';
+
+import { useState, useRef, useEffect } from 'react';
+import { useI18n } from '@/lib/hooks/use-i18n';
+import { supportedLocales } from '@/lib/i18n';
+import { cn } from '@/lib/utils';
+
+interface LanguageSwitcherProps {
+  /** Called when the dropdown opens, so parent can close sibling dropdowns */
+  onOpen?: () => void;
+}
+
+export function LanguageSwitcher({ onOpen }: LanguageSwitcherProps) {
+  const { locale, setLocale } = useI18n();
+  const [open, setOpen] = useState(false);
+  const ref = useRef<HTMLDivElement>(null);
+
+  // Close on click outside
+  useEffect(() => {
+    if (!open) return;
+    const handler = (e: MouseEvent) => {
+      if (ref.current && !ref.current.contains(e.target as Node)) {
+        setOpen(false);
+      }
+    };
+    document.addEventListener('mousedown', handler);
+    return () => document.removeEventListener('mousedown', handler);
+  }, [open]);
+
+  return (
+    <div className="relative" ref={ref}>
+      <button
+        onClick={() => {
+          const next = !open;
+          setOpen(next);
+          if (next) onOpen?.();
+        }}
+        className="flex items-center gap-1 px-3 py-1.5 rounded-full text-xs font-bold text-gray-500 dark:text-gray-400 hover:bg-white dark:hover:bg-gray-700 hover:text-gray-800 dark:hover:text-gray-200 hover:shadow-sm transition-all"
+      >
+        {supportedLocales.find((l) => l.code === locale)?.shortLabel ?? locale}
+      </button>
+      {open && (
+        <div className="absolute top-full mt-2 right-0 bg-white dark:bg-gray-800 border border-gray-200 dark:border-gray-700 rounded-lg shadow-lg overflow-hidden z-50 min-w-[120px]">
+          {supportedLocales.map((l) => (
+            <button
+              key={l.code}
+              onClick={() => {
+                setLocale(l.code);
+                setOpen(false);
+              }}
+              className={cn(
+                'w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors',
+                locale === l.code &&
+                  'bg-purple-50 dark:bg-purple-900/20 text-purple-600 dark:text-purple-400',
+              )}
+            >
+              {l.label}
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}
diff --git a/components/scene-renderers/pbl-renderer.tsx b/components/scene-renderers/pbl-renderer.tsx
index 550b71da3..6a2792c3a 100644
--- a/components/scene-renderers/pbl-renderer.tsx
+++ b/components/scene-renderers/pbl-renderer.tsx
@@ -44,9 +44,10 @@ export function PBLRenderer({ content, mode: _mode, sceneId }: PBLRendererProps)
       // Add Question Agent welcome message if chat is empty and active issue has questions
       const activeIssue = newConfig.issueboard.issues.find((i) => i.is_active);
       if (activeIssue?.generated_questions && newConfig.chat.messages.length === 0) {
-        const welcomeMsg = t('pbl.chat.welcomeMessage')
-          .replace('{title}', activeIssue.title)
-          .replace('{questions}', activeIssue.generated_questions);
+        const welcomeMsg = t('pbl.chat.welcomeMessage', {
+          title: activeIssue.title,
+          questions: activeIssue.generated_questions,
+        });
         newConfig.chat = {
           messages: [
             {
diff --git a/components/scene-renderers/pbl/use-pbl-chat.ts b/components/scene-renderers/pbl/use-pbl-chat.ts
index 8c41ff85b..2708e6fc7 100644
--- a/components/scene-renderers/pbl/use-pbl-chat.ts
+++ b/components/scene-renderers/pbl/use-pbl-chat.ts
@@ -165,7 +165,7 @@ async function handleIssueComplete(
   config: PBLProjectConfig,
   completedIssue: PBLIssue,
   headers: Record<string, string>,
-  t: (key: string) => string,
+  t: (key: string, options?: Record<string, unknown>) => string,
 ) {
   // Mark current issue as done
   const issue = config.issueboard.issues.find((i) => i.id === completedIssue.id);
@@ -226,9 +226,10 @@ async function handleIssueComplete(
           config.chat.messages.push({
             id: `msg_${Date.now()}_welcome`,
             agent_name: nextIssue.question_agent_name,
-            message: t('pbl.chat.welcomeMessage')
-              .replace('{title}', nextIssue.title)
-              .replace('{questions}', data.message),
+            message: t('pbl.chat.welcomeMessage', {
+              title: nextIssue.title,
+              questions: data.message,
+            }),
             timestamp: Date.now(),
             read_by: [],
           });
@@ -241,9 +242,10 @@ async function handleIssueComplete(
       config.chat.messages.push({
         id: `msg_${Date.now()}_welcome`,
         agent_name: nextIssue.question_agent_name,
-        message: t('pbl.chat.welcomeMessage')
-          .replace('{title}', nextIssue.title)
-          .replace('{questions}', nextIssue.generated_questions),
+        message: t('pbl.chat.welcomeMessage', {
+          title: nextIssue.title,
+          questions: nextIssue.generated_questions,
+        }),
         timestamp: Date.now(),
         read_by: [],
       });
@@ -253,9 +255,10 @@ async function handleIssueComplete(
     config.chat.messages.push({
       id: `msg_${Date.now()}_system`,
       agent_name: 'System',
-      message: t('pbl.chat.issueCompleteMessage')
-        .replace('{completed}', completedIssue.title)
-        .replace('{next}', nextIssue.title),
+      message: t('pbl.chat.issueCompleteMessage', {
+        completed: completedIssue.title,
+        next: nextIssue.title,
+      }),
       timestamp: Date.now(),
       read_by: [],
     });
diff --git a/components/settings/agent-settings.tsx b/components/settings/agent-settings.tsx
index 6978bff73..ad0c9aa8a 100644
--- a/components/settings/agent-settings.tsx
+++ b/components/settings/agent-settings.tsx
@@ -159,10 +159,9 @@ export function AgentSettings({
                 <span className="flex items-center gap-1.5">
                   <Users className="h-4 w-4" />
                   <strong>{t('settings.multiAgentMode')}</strong> -{' '}
-                  {t('settings.agentsCollaboratingCount').replace(
-                    '{count}',
-                    String(selectedAgentIds.length),
-                  )}
+                  {t('settings.agentsCollaboratingCount', {
+                    count: selectedAgentIds.length,
+                  })}
                 </span>
               )}
             </div>
diff --git a/components/whiteboard/whiteboard-history.tsx b/components/whiteboard/whiteboard-history.tsx
index 853292f43..e89274214 100644
--- a/components/whiteboard/whiteboard-history.tsx
+++ b/components/whiteboard/whiteboard-history.tsx
@@ -142,10 +142,7 @@ export function WhiteboardHistory({ isOpen, onClose }: WhiteboardHistoryProps) {
                         </div>
                         <div className="text-xs text-gray-400 dark:text-gray-500 mt-0.5">
                           {formatTime(snap.timestamp)} ·{' '}
-                          {t('whiteboard.elementCount').replace(
-                            '{count}',
-                            String(snap.elements.length),
-                          )}
+                          {t('whiteboard.elementCount', { count: snap.elements.length })}
                         </div>
                       </div>
                       <button
diff --git a/lib/hooks/use-i18n.tsx b/lib/hooks/use-i18n.tsx
index 4e642f4c2..18936cc1c 100644
--- a/lib/hooks/use-i18n.tsx
+++ b/lib/hooks/use-i18n.tsx
@@ -1,47 +1,59 @@
 'use client';
 
-import { createContext, useContext, useState, useEffect, ReactNode } from 'react';
-import { Locale, translate, defaultLocale } from '@/lib/i18n';
+import { createContext, useContext, useEffect, ReactNode } from 'react';
+import { useTranslation } from 'react-i18next';
+import { type Locale, defaultLocale, supportedLocales } from '@/lib/i18n';
+import '@/lib/i18n/config';
+
+const LOCALE_STORAGE_KEY = 'locale';
+
+/** Match a browser language code (e.g. 'en', 'zh-TW') to a supported locale */
+function resolveLocale(lang: string): Locale {
+  // Exact match
+  const exact = supportedLocales.find((l) => l.code === lang);
+  if (exact) return exact.code;
+  // Prefix match: 'en' → 'en-US', 'zh' → 'zh-CN'
+  const prefix = lang.split('-')[0].toLowerCase();
+  const match = supportedLocales.find((l) => l.code.toLowerCase().startsWith(prefix));
+  return match?.code ?? defaultLocale;
+}
 
 type I18nContextType = {
   locale: Locale;
   setLocale: (locale: Locale) => void;
-  t: (key: string) => string;
+  t: (key: string, options?: Record<string, unknown>) => string;
 };
 
-const LOCALE_STORAGE_KEY = 'locale';
-const VALID_LOCALES: Locale[] = ['zh-CN', 'en-US'];
-
 const I18nContext = createContext<I18nContextType | undefined>(undefined);
 
 export function I18nProvider({ children }: { children: ReactNode }) {
-  const [locale, setLocaleState] = useState<Locale>(defaultLocale);
+  const { t, i18n } = useTranslation();
 
-  // Hydrate from localStorage after mount (avoids SSR mismatch)
-  /* eslint-disable react-hooks/set-state-in-effect -- Hydration from localStorage must happen in effect */
+  const locale = (i18n.language || defaultLocale) as Locale;
+
+  // Detect language after hydration to avoid SSR mismatch.
+  // i18next handles fallback automatically: if the detected language
+  // has no matching JSON file, it falls back to fallbackLng.
   useEffect(() => {
     try {
       const stored = localStorage.getItem(LOCALE_STORAGE_KEY);
-      if (stored && VALID_LOCALES.includes(stored as Locale)) {
-        setLocaleState(stored as Locale);
-        return;
-      }
-      const detected = navigator.language?.startsWith('zh') ? 'zh-CN' : 'en-US';
-      localStorage.setItem(LOCALE_STORAGE_KEY, detected);
-      setLocaleState(detected);
+      const raw = stored || navigator.language || defaultLocale;
+      const target = resolveLocale(raw);
+      if (target !== i18n.language) i18n.changeLanguage(target);
     } catch {
       // localStorage unavailable, keep default
     }
-  }, []);
-  /* eslint-enable react-hooks/set-state-in-effect */
+  }, []); // eslint-disable-line react-hooks/exhaustive-deps
 
   const setLocale = (newLocale: Locale) => {
-    setLocaleState(newLocale);
-    localStorage.setItem(LOCALE_STORAGE_KEY, newLocale);
+    i18n.changeLanguage(newLocale);
+    try {
+      localStorage.setItem(LOCALE_STORAGE_KEY, newLocale);
+    } catch {
+      // localStorage unavailable
+    }
   };
 
-  const t = (key: string): string => translate(locale, key);
-
   return <I18nContext.Provider value={{ locale, setLocale, t }}>{children}</I18nContext.Provider>;
 }
 
diff --git a/lib/i18n/TRANSLATION_GUIDE.md b/lib/i18n/TRANSLATION_GUIDE.md
new file mode 100644
index 000000000..d2f0863f2
--- /dev/null
+++ b/lib/i18n/TRANSLATION_GUIDE.md
@@ -0,0 +1,33 @@
+# Translation Guide
+
+## Adding a new language
+
+1. Copy `locales/en-US.json` to `locales/<code>.json` (e.g. `ja-JP.json`)
+2. Append an entry to the end of the `supportedLocales` array in `locales.ts` — do not reorder existing entries, as the first locale for each language prefix (e.g. `zh-CN` for `zh`) is used as the default when the browser sends a bare language code:
+   ```ts
+   { code: 'ja-JP', label: '日本語', shortLabel: 'JA' },
+   ```
+3. Translate all values in the new JSON file. Keys must remain identical.
+
+## Interpolation
+
+This project uses i18next with the default double-brace syntax: `{{variable}}`.
+
+Example: `"Hi, {{name}}"` will render as `"Hi, Alice"` when called with `t('key', { name: 'Alice' })`.
+
+Do NOT remove or rename interpolation variables — they are referenced in code.
+
+## Keys with design intent
+
+Not every key needs explanation, but the following have non-obvious UX context that affects how they should be translated.
+
+| Key | Where it appears | Translation notes |
+|-----|-----------------|-------------------|
+| `home.greetingWithName` | Top-left of homepage, clickable pill that opens nickname editor | This is a **call-to-action** — the greeting doubles as an entry point for users to set their nickname. The translation must include `{{name}}` and read naturally with the default nickname (see `profile.defaultNickname`). Avoid generic greetings that hide the name (e.g. don't translate as just "Welcome"). |
+| `profile.defaultNickname` | Pre-filled in the greeting and the nickname input field | Shown before the user sets a real name. Pick a warm, gender-neutral word that: (1) feels natural in the greeting, (2) clearly signals "this is a placeholder you should replace". Avoid cold terms like "User" or formal terms like "Student". Examples: EN "Learner", ZH "同学". |
+| `profile.bioPlaceholder` | Textarea placeholder in the profile editor | The bio is fed to the AI teacher to personalize lessons. The placeholder should hint at this — tell users *why* filling it in helps. |
+| `pbl.chat.welcomeMessage` | First message from the Question Agent in PBL mode | Contains `{{title}}` (issue title) and `{{questions}}` (multi-line generated text). The `{{questions}}` block can be long — make sure surrounding text doesn't make the message feel cluttered. Keep the framing concise. |
+| `pbl.chat.issueCompleteMessage` | System message when a PBL issue is completed | Contains `{{completed}}` and `{{next}}`. Should feel like a natural progression, not a mechanical status update. |
+| `generation.textTruncated` / `generation.imageTruncated` | Toast warnings during PDF-based course generation | These are technical warnings shown briefly. Keep them short and factual. `textTruncated` has `{{n}}` (character count), `imageTruncated` has `{{total}}` and `{{max}}`. |
+| `agentBar.readyToLearn` | Classroom page, above the agent role list | Conversational prompt to set the mood before class starts. Should feel inviting, not instructional. |
+| `settings.agentsCollaboratingCount` | Settings panel, multi-agent mode description | Contains `{{count}}`. This is a status label, not a button — keep it descriptive. |
diff --git a/lib/i18n/chat.ts b/lib/i18n/chat.ts
deleted file mode 100644
index 1bb535d3e..000000000
--- a/lib/i18n/chat.ts
+++ /dev/null
@@ -1,147 +0,0 @@
-export const chatZhCN = {
-  chat: {
-    lecture: '授课',
-    noConversations: '暂无对话',
-    startConversation: '输入消息开始对话',
-    noMessages: '暂无消息',
-    ended: '已结束',
-    unknown: '未知',
-    stopDiscussion: '结束讨论',
-    endQA: '结束问答',
-    tabs: {
-      lecture: '笔记',
-      chat: '对话',
-    },
-    lectureNotes: {
-      empty: '播放课程后，笔记将在此显示',
-      emptyHint: '点击播放按钮开始授课',
-      pageLabel: '第 {n} 页',
-      currentPage: '当前页',
-    },
-    badge: {
-      qa: 'Q&A',
-      discussion: '讨论',
-      lecture: '授课',
-    },
-  },
-  actions: {
-    names: {
-      spotlight: '聚光灯',
-      laser: '激光笔',
-      wb_open: '打开白板',
-      wb_draw_text: '白板文本',
-      wb_draw_shape: '白板形状',
-      wb_draw_chart: '白板图表',
-      wb_draw_latex: '白板公式',
-      wb_draw_table: '白板表格',
-      wb_draw_line: '白板线条',
-      wb_clear: '清空白板',
-      wb_delete: '删除元素',
-      wb_close: '关闭白板',
-      discussion: '课堂讨论',
-    },
-    status: {
-      inputStreaming: '等待中',
-      inputAvailable: '执行中',
-      outputAvailable: '已完成',
-      outputError: '错误',
-      outputDenied: '已拒绝',
-      running: '执行中',
-      result: '已完成',
-      error: '错误',
-    },
-  },
-  agentBar: {
-    readyToLearn: '准备好一起学习了吗？',
-    expandedTitle: '课堂角色配置',
-    configTooltip: '点击配置课堂角色',
-    voiceLabel: '音色',
-    voiceLoading: '加载中...',
-    voiceAutoAssign: '音色将自动分配',
-  },
-  proactiveCard: {
-    discussion: '讨论',
-    join: '加入讨论',
-    skip: '跳过',
-    pause: '暂停',
-    resume: '继续',
-  },
-  voice: {
-    startListening: '语音输入',
-    stopListening: '停止录音',
-  },
-} as const;
-
-export const chatEnUS = {
-  chat: {
-    lecture: 'Lecture',
-    noConversations: 'No conversations',
-    startConversation: 'Type a message below to begin chatting',
-    noMessages: 'No messages yet',
-    ended: 'ended',
-    unknown: 'Unknown',
-    stopDiscussion: 'Stop Discussion',
-    endQA: 'End Q&A',
-    tabs: {
-      lecture: 'Notes',
-      chat: 'Chat',
-    },
-    lectureNotes: {
-      empty: 'Notes will appear here after lecture playback',
-      emptyHint: 'Press play to start the lecture',
-      pageLabel: 'Page {n}',
-      currentPage: 'Current',
-    },
-    badge: {
-      qa: 'Q&A',
-      discussion: 'DISC',
-      lecture: 'LEC',
-    },
-  },
-  actions: {
-    names: {
-      spotlight: 'Spotlight',
-      laser: 'Laser',
-      wb_open: 'Open Whiteboard',
-      wb_draw_text: 'Whiteboard Text',
-      wb_draw_shape: 'Whiteboard Shape',
-      wb_draw_chart: 'Whiteboard Chart',
-      wb_draw_latex: 'Whiteboard Formula',
-      wb_draw_table: 'Whiteboard Table',
-      wb_draw_line: 'Whiteboard Line',
-      wb_clear: 'Clear Whiteboard',
-      wb_delete: 'Delete Element',
-      wb_close: 'Close Whiteboard',
-      discussion: 'Discussion',
-    },
-    status: {
-      inputStreaming: 'Waiting',
-      inputAvailable: 'Executing',
-      outputAvailable: 'Completed',
-      outputError: 'Error',
-      outputDenied: 'Denied',
-      running: 'Executing',
-      result: 'Completed',
-      error: 'Error',
-    },
-  },
-  agentBar: {
-    readyToLearn: 'Ready to learn together?',
-    expandedTitle: 'Classroom Role Config',
-    configTooltip: 'Click to configure classroom roles',
-    voiceLabel: 'Voice',
-    voiceLoading: 'Loading...',
-    voiceAutoAssign: 'Voices will be auto-assigned',
-  },
-  proactiveCard: {
-    discussion: 'Discussion',
-    join: 'Join',
-    skip: 'Skip',
-    pause: 'Pause',
-    resume: 'Resume',
-  },
-  voice: {
-    startListening: 'Voice input',
-    stopListening: 'Stop recording',
-  },
-} as const;
diff --git a/lib/i18n/common.ts b/lib/i18n/common.ts
deleted file mode 100644
index 1bceb5d61..000000000
--- a/lib/i18n/common.ts
+++ /dev/null
@@ -1,81 +0,0 @@
-export const commonZhCN = {
-  common: {
-    you: '你',
-    confirm: '确定',
-    cancel: '取消',
-    loading: '加载中...',
-  },
-  home: {
-    slogan: 'Generative Learning in Multi-Agent Interactive Classroom',
-    greeting: '嗨，',
-  },
-  toolbar: {
-    languageHint: '课程将以此语言生成',
-    pdfParser: '解析器',
-    pdfUpload: '上传 PDF',
-    removePdf: '移除文件',
-    webSearchOn: '已开启',
-    webSearchOff: '点击开启',
-    webSearchDesc: '生成前搜索网络获取最新资料，让内容更丰富准确',
-    webSearchProvider: '搜索引擎',
-    webSearchNoProvider: '请在设置中配置搜索引擎 API Key',
-    selectProvider: '选择模型服务商',
-    configureProvider: '配置模型',
-    configureProviderHint: '请先配置至少一个模型服务商才能生成课程',
-    enterClassroom: '进入课堂',
-    advancedSettings: '高级设置',
-    ttsTitle: '语音合成',
-    ttsHint: '选择 AI 教师的朗读音色',
-    ttsPreview: '试听',
-    ttsPreviewing: '播放中...',
-  },
-  export: {
-    pptx: '导出 PPTX',
-    resourcePack: '导出教学资源包',
-    resourcePackDesc: 'PPTX + 交互式页面',
-    exporting: '正在导出...',
-    exportSuccess: '导出成功',
-    exportFailed: '导出失败',
-  },
-} as const;
-
-export const commonEnUS = {
-  common: {
-    you: 'You',
-    confirm: 'Confirm',
-    cancel: 'Cancel',
-    loading: 'Loading...',
-  },
-  home: {
-    slogan: 'Generative Learning in Multi-Agent Interactive Classroom',
-    greeting: 'Hi, ',
-  },
-  toolbar: {
-    languageHint: 'Course will be generated in this language',
-    pdfParser: 'Parser',
-    pdfUpload: 'Upload PDF',
-    removePdf: 'Remove file',
-    webSearchOn: 'Enabled',
-    webSearchOff: 'Click to enable',
-    webSearchDesc: 'Search the web for up-to-date information before generation',
-    webSearchProvider: 'Search engine',
-    webSearchNoProvider: 'Configure search API key in Settings',
-    selectProvider: 'Select provider',
-    configureProvider: 'Set up model',
-    configureProviderHint: 'Configure at least one model provider to generate courses',
-    enterClassroom: 'Enter Classroom',
-    advancedSettings: 'Advanced Settings',
-    ttsTitle: 'Text-to-Speech',
-    ttsHint: 'Choose a voice for the AI teacher',
-    ttsPreview: 'Preview',
-    ttsPreviewing: 'Playing...',
-  },
-  export: {
-    pptx: 'Export PPTX',
-    resourcePack: 'Export Resource Pack',
-    resourcePackDesc: 'PPTX + interactive pages',
-    exporting: 'Exporting...',
-    exportSuccess: 'Export successful',
-    exportFailed: 'Export failed',
-  },
-} as const;
diff --git a/lib/i18n/config.ts b/lib/i18n/config.ts
new file mode 100644
index 000000000..f0a427800
--- /dev/null
+++ b/lib/i18n/config.ts
@@ -0,0 +1,19 @@
+import i18n from 'i18next';
+import { initReactI18next } from 'react-i18next';
+import resourcesToBackend from 'i18next-resources-to-backend';
+import { supportedLocales } from './locales';
+import { defaultLocale } from './types';
+
+i18n
+  .use(initReactI18next)
+  .use(resourcesToBackend((language: string) => import(`./locales/${language}.json`)))
+  .init({
+    lng: defaultLocale,
+    fallbackLng: defaultLocale,
+    supportedLngs: supportedLocales.map((l) => l.code),
+    interpolation: {
+      escapeValue: false,
+    },
+  });
+
+export default i18n;
diff --git a/lib/i18n/generation.ts b/lib/i18n/generation.ts
deleted file mode 100644
index e5707445f..000000000
--- a/lib/i18n/generation.ts
+++ /dev/null
@@ -1,141 +0,0 @@
-export const generationZhCN = {
-  classroom: {
-    recentClassrooms: '最近学习',
-    today: '今天',
-    yesterday: '昨天',
-    daysAgo: '天前',
-    slides: '页',
-    nameCopied: '课堂名称已复制',
-    deleteConfirmTitle: '删除课堂',
-    delete: '删除',
-    rename: '重命名',
-    renamePlaceholder: '输入课堂名称',
-    renameFailed: '重命名失败',
-  },
-  upload: {
-    pdfSizeLimit: '支持最大50MB的PDF文件',
-    generateFailed: '生成课堂失败，请重试',
-    requirementPlaceholder:
-      '输入你想学的任何内容，例如：\n「从零学 Python，30 分钟写出第一个程序」\n「用白板给我讲解傅里叶变换」\n「阿瓦隆桌游怎么玩」',
-    requirementRequired: '请输入课程需求',
-    fileTooLarge: '文件过大，请选择小于50MB的PDF文件',
-  },
-  generation: {
-    // Progress steps (used dynamically via activeStep)
-    analyzingPdf: '解析 PDF 文档',
-    analyzingPdfDesc: '正在提取文档结构和内容...',
-    pdfLoadFailed: '无法加载 PDF 文件，请重试',
-    pdfParseFailed: 'PDF 解析失败',
-    streamNotReadable: '无法读取生成数据流',
-    generatingOutlines: '生成课程大纲',
-    generatingOutlinesDesc: '正在构建学习路径...',
-    generatingSlideContent: '生成页面内容',
-    generatingSlideContentDesc: '正在创建幻灯片、测验和互动内容...',
-    generatingActions: '生成教学动作',
-    generatingActionsDesc: '正在编排讲解、聚焦和互动流程...',
-    generationComplete: '生成完成！',
-    generationFailed: '生成失败',
-    generatingCourse: '正在生成课程',
-    openingClassroom: '即将打开课堂...',
-    outlineReady: '课程大纲已生成',
-    generatingFirstPage: '首页内容生成中...',
-    firstPageReady: '首页已就绪！正在打开课堂...',
-    speechFailed: '语音合成失败',
-    retryScene: '重试生成',
-    retryingScene: '正在重新生成...',
-    backToHome: '返回首页',
-    sessionNotFound: '未找到生成会话',
-    sessionNotFoundDesc: '请先填写课程需求开始生成流程。',
-    goBackAndRetry: '返回重试',
-    classroomReady: '你的个性化AI学习环境已成功生成。',
-    aiWorking: 'AI智能体工作中...',
-    textTruncated: '文档文本较长，已截取前 {n} 字符用于生成',
-    imageTruncated: '文档含 {total} 张图片，超出上限 {max} 张，多余图片将仅以文字描述传递',
-    // Agent generation
-    agentGeneration: '生成课堂角色',
-    agentGenerationDesc: '正在根据课程内容生成角色...',
-    agentRevealTitle: '你的课堂角色',
-    viewAgents: '查看角色',
-    continue: '继续',
-    // Outline errors
-    outlineRetrying: '大纲生成异常，正在重试...',
-    outlineEmptyResponse: '模型未返回有效的大纲内容，请检查模型配置后重试',
-    outlineGenerateFailed: '大纲生成失败，请稍后重试',
-    // Web Search
-    webSearching: '网络搜索',
-    webSearchingDesc: '正在搜索网络获取最新资料',
-    webSearchFailed: '网络搜索失败',
-  },
-} as const;
-
-export const generationEnUS = {
-  classroom: {
-    recentClassrooms: 'Recent',
-    today: 'Today',
-    yesterday: 'Yesterday',
-    daysAgo: 'days ago',
-    slides: 'slides',
-    nameCopied: 'Name copied',
-    deleteConfirmTitle: 'Delete',
-    delete: 'Delete',
-    rename: 'Rename',
-    renamePlaceholder: 'Enter classroom name',
-    renameFailed: 'Failed to rename classroom',
-  },
-  upload: {
-    pdfSizeLimit: 'Supports PDF files up to 50MB',
-    generateFailed: 'Failed to generate classroom, please try again',
-    requirementPlaceholder:
-      'Tell me anything you want to learn, e.g.\n"Teach me Python from scratch in 30 minutes"\n"Explain Fourier Transform on the whiteboard"\n"How to play the board game Avalon"',
-    requirementRequired: 'Please enter course requirements',
-    fileTooLarge: 'File too large. Please select a PDF file smaller than 50MB',
-  },
-  generation: {
-    // Progress steps (used dynamically via activeStep)
-    analyzingPdf: 'Analyzing PDF Document',
-    analyzingPdfDesc: 'Extracting document structure and content...',
-    pdfLoadFailed: 'Failed to load PDF file, please try again',
-    pdfParseFailed: 'PDF parsing failed',
-    streamNotReadable: 'Unable to read generation stream',
-    generatingOutlines: 'Drafting Course Outline',
-    generatingOutlinesDesc: 'Structuring the learning path...',
-    generatingSlideContent: 'Generating Page Content',
-    generatingSlideContentDesc: 'Creating slides, quizzes, and interactive content...',
-    generatingActions: 'Generating Teaching Actions',
-    generatingActionsDesc: 'Orchestrating narration, spotlights, and interactions...',
-    generationComplete: 'Generation complete!',
-    generationFailed: 'Generation failed',
-    generatingCourse: 'Generating course',
-    openingClassroom: 'Opening classroom...',
-    outlineReady: 'Course outline generated',
-    generatingFirstPage: 'Generating first page...',
-    firstPageReady: 'First page ready! Opening classroom...',
-    speechFailed: 'Speech generation failed',
-    retryScene: 'Retry',
-    retryingScene: 'Regenerating...',
-    backToHome: 'Back to Home',
-    sessionNotFound: 'Session Not Found',
-    sessionNotFoundDesc: 'Please fill in course requirements to start the generation process.',
-    goBackAndRetry: 'Go Back and Retry',
-    classroomReady: 'Your personalized AI learning environment has been generated successfully.',
-    aiWorking: 'AI Agents Working...',
-    textTruncated: 'Document text is long, using first {n} characters for generation',
-    imageTruncated:
-      '{total} images found, exceeding the {max} image limit. Extra images will use text descriptions only',
-    // Agent generation
-    agentGeneration: 'Generating Classroom Roles',
-    agentGenerationDesc: 'Generating roles based on course content...',
-    agentRevealTitle: 'Your Classroom Roles',
-    viewAgents: 'View Roles',
-    continue: 'Continue',
-    // Outline errors
-    outlineRetrying: 'Outline generation issue, retrying...',
-    outlineEmptyResponse:
-      'Model returned no valid outlines. Please check model configuration and try again',
-    outlineGenerateFailed: 'Outline generation failed, please try again later',
-    // Web Search
-    webSearching: 'Web Search',
-    webSearchingDesc: 'Searching the web for up-to-date information',
-    webSearchFailed: 'Web search failed',
-  },
-} as const;
diff --git a/lib/i18n/index.ts b/lib/i18n/index.ts
index 5fd70da52..e845b2794 100644
--- a/lib/i18n/index.ts
+++ b/lib/i18n/index.ts
@@ -1,52 +1,13 @@
-import { defaultLocale, type Locale } from './types';
-export { type Locale, defaultLocale } from './types';
-import { commonZhCN, commonEnUS } from './common';
-import { stageZhCN, stageEnUS } from './stage';
-import { chatZhCN, chatEnUS } from './chat';
-import { generationZhCN, generationEnUS } from './generation';
-import { settingsZhCN, settingsEnUS } from './settings';
-
-export const translations = {
-  'zh-CN': {
-    ...commonZhCN,
-    ...stageZhCN,
-    ...chatZhCN,
-    ...generationZhCN,
-    ...settingsZhCN,
-  },
-  'en-US': {
-    ...commonEnUS,
-    ...stageEnUS,
-    ...chatEnUS,
-    ...generationEnUS,
-    ...settingsEnUS,
-  },
-} as const;
+import i18n from './config';
 
-export type TranslationKey = keyof (typeof translations)[typeof defaultLocale];
+export { type Locale, defaultLocale } from './types';
+export { type LocaleEntry, supportedLocales } from './locales';
+export type TranslationKey = string;
 
-export function translate(locale: Locale, key: string): string {
-  const keys = key.split('.');
-  let value: unknown = translations[locale];
-  for (const k of keys) {
-    value = (value as Record<string, unknown>)?.[k];
-  }
-  return (typeof value === 'string' ? value : undefined) ?? key;
+export function translate(locale: string, key: string): string {
+  return i18n.t(key, { lng: locale });
 }
 
 export function getClientTranslation(key: string): string {
-  let locale: Locale = defaultLocale;
-
-  if (typeof window !== 'undefined') {
-    try {
-      const storedLocale = localStorage.getItem('locale');
-      if (storedLocale === 'zh-CN' || storedLocale === 'en-US') {
-        locale = storedLocale;
-      }
-    } catch {
-      // localStorage unavailable, keep default locale
-    }
-  }
-
-  return translate(locale, key);
+  return i18n.t(key);
 }
diff --git a/lib/i18n/locales.ts b/lib/i18n/locales.ts
new file mode 100644
index 000000000..b155914f5
--- /dev/null
+++ b/lib/i18n/locales.ts
@@ -0,0 +1,19 @@
+export type LocaleEntry = {
+  code: string;
+  /** Native name shown in dropdown, e.g. '简体中文' */
+  label: string;
+  /** Short label shown on the toggle button, e.g. 'CN' */
+  shortLabel: string;
+};
+
+/**
+ * Supported locales registry.
+ *
+ * To add a new language:
+ *   1. Create `lib/i18n/locales/<code>.json` (copy an existing file as template)
+ *   2. Add an entry here
+ */
+export const supportedLocales = [
+  { code: 'zh-CN', label: '简体中文', shortLabel: 'CN' },
+  { code: 'en-US', label: 'English', shortLabel: 'EN' },
+] as const satisfies readonly LocaleEntry[];
diff --git a/lib/i18n/locales/en-US.json b/lib/i18n/locales/en-US.json
new file mode 100644
index 000000000..b154b4144
--- /dev/null
+++ b/lib/i18n/locales/en-US.json
@@ -0,0 +1,877 @@
+{
+  "common": {
+    "you": "You",
+    "confirm": "Confirm",
+    "cancel": "Cancel",
+    "loading": "Loading..."
+  },
+  "home": {
+    "slogan": "Generative Learning in Multi-Agent Interactive Classroom",
+    "greetingWithName": "Hi, {{name}}"
+  },
+  "toolbar": {
+    "languageHint": "Course will be generated in this language",
+    "pdfParser": "Parser",
+    "pdfUpload": "Upload PDF",
+    "removePdf": "Remove file",
+    "webSearchOn": "Enabled",
+    "webSearchOff": "Click to enable",
+    "webSearchDesc": "Search the web for up-to-date information before generation",
+    "webSearchProvider": "Search engine",
+    "webSearchNoProvider": "Configure search API key in Settings",
+    "selectProvider": "Select provider",
+    "configureProvider": "Set up model",
+    "configureProviderHint": "Configure at least one model provider to generate courses",
+    "enterClassroom": "Enter Classroom",
+    "advancedSettings": "Advanced Settings",
+    "ttsTitle": "Text-to-Speech",
+    "ttsHint": "Choose a voice for the AI teacher",
+    "ttsPreview": "Preview",
+    "ttsPreviewing": "Playing..."
+  },
+  "export": {
+    "pptx": "Export PPTX",
+    "resourcePack": "Export Resource Pack",
+    "resourcePackDesc": "PPTX + interactive pages",
+    "exporting": "Exporting...",
+    "exportSuccess": "Export successful",
+    "exportFailed": "Export failed"
+  },
+  "chat": {
+    "lecture": "Lecture",
+    "noConversations": "No conversations",
+    "startConversation": "Type a message below to begin chatting",
+    "noMessages": "No messages yet",
+    "ended": "ended",
+    "unknown": "Unknown",
+    "stopDiscussion": "Stop Discussion",
+    "endQA": "End Q&A",
+    "tabs": {
+      "lecture": "Notes",
+      "chat": "Chat"
+    },
+    "lectureNotes": {
+      "empty": "Notes will appear here after lecture playback",
+      "emptyHint": "Press play to start the lecture",
+      "pageLabel": "Page {{n}}",
+      "currentPage": "Current"
+    },
+    "badge": {
+      "qa": "Q&A",
+      "discussion": "DISC",
+      "lecture": "LEC"
+    }
+  },
+  "actions": {
+    "names": {
+      "spotlight": "Spotlight",
+      "laser": "Laser",
+      "wb_open": "Open Whiteboard",
+      "wb_draw_text": "Whiteboard Text",
+      "wb_draw_shape": "Whiteboard Shape",
+      "wb_draw_chart": "Whiteboard Chart",
+      "wb_draw_latex": "Whiteboard Formula",
+      "wb_draw_table": "Whiteboard Table",
+      "wb_draw_line": "Whiteboard Line",
+      "wb_clear": "Clear Whiteboard",
+      "wb_delete": "Delete Element",
+      "wb_close": "Close Whiteboard",
+      "discussion": "Discussion"
+    },
+    "status": {
+      "inputStreaming": "Waiting",
+      "inputAvailable": "Executing",
+      "outputAvailable": "Completed",
+      "outputError": "Error",
+      "outputDenied": "Denied",
+      "running": "Executing",
+      "result": "Completed",
+      "error": "Error"
+    }
+  },
+  "agentBar": {
+    "readyToLearn": "Ready to learn together?",
+    "expandedTitle": "Classroom Role Config",
+    "configTooltip": "Click to configure classroom roles",
+    "voiceLabel": "Voice",
+    "voiceLoading": "Loading...",
+    "voiceAutoAssign": "Voices will be auto-assigned"
+  },
+  "proactiveCard": {
+    "discussion": "Discussion",
+    "join": "Join",
+    "skip": "Skip",
+    "pause": "Pause",
+    "resume": "Resume"
+  },
+  "voice": {
+    "startListening": "Voice input",
+    "stopListening": "Stop recording"
+  },
+  "stage": {
+    "currentScene": "Current Scene",
+    "generating": "Generating...",
+    "paused": "Paused",
+    "generationFailed": "Generation failed",
+    "confirmSwitchTitle": "Switch Scene",
+    "confirmSwitchMessage": "A topic is currently in progress. Switching scenes will end the current topic. Are you sure?",
+    "generatingNextPage": "Scene is being generated, please wait...",
+    "fullscreen": "Fullscreen",
+    "exitFullscreen": "Exit Fullscreen"
+  },
+  "whiteboard": {
+    "title": "Interactive Whiteboard",
+    "open": "Open Whiteboard",
+    "clear": "Clear Whiteboard",
+    "minimize": "Minimize Whiteboard",
+    "ready": "Whiteboard is ready",
+    "readyHint": "Elements will appear here when added by AI",
+    "clearSuccess": "Whiteboard cleared successfully",
+    "clearError": "Failed to clear whiteboard: ",
+    "resetView": "Reset View",
+    "restoreError": "Failed to restore whiteboard: ",
+    "history": "History",
+    "restore": "Restore",
+    "noHistory": "No history yet",
+    "restored": "Whiteboard restored",
+    "elementCount": "{{count}} elements"
+  },
+  "quiz": {
+    "title": "Quiz",
+    "subtitle": "Test your knowledge",
+    "questionsCount": "questions",
+    "totalPrefix": "",
+    "pointsSuffix": "pts",
+    "startQuiz": "Start Quiz",
+    "multipleChoiceHint": "(Multiple choice — select all correct answers)",
+    "inputPlaceholder": "Type your answer here...",
+    "charCount": "chars",
+    "yourAnswer": "Your answer:",
+    "notAnswered": "Not answered",
+    "aiComment": "AI Feedback",
+    "singleChoice": "Single",
+    "multipleChoice": "Multiple",
+    "shortAnswer": "Short answer",
+    "analysis": "Analysis: ",
+    "excellent": "Excellent!",
+    "keepGoing": "Keep going!",
+    "needsReview": "Needs review",
+    "correct": "correct",
+    "incorrect": "incorrect",
+    "answering": "In Progress",
+    "submitAnswers": "Submit Answers",
+    "aiGrading": "AI is grading...",
+    "aiGradingWait": "Please wait, analyzing your answers",
+    "quizReport": "Quiz Report",
+    "retry": "Retry"
+  },
+  "roundtable": {
+    "teacher": "TEACHER",
+    "you": "YOU",
+    "inputPlaceholder": "Type your message...",
+    "listening": "Listening...",
+    "processing": "Processing...",
+    "noSpeechDetected": "No speech detected, please try again",
+    "discussionEnded": "Discussion ended",
+    "qaEnded": "Q&A ended",
+    "thinking": "Thinking",
+    "yourTurn": "Your turn",
+    "stopDiscussion": "Stop Discussion",
+    "autoPlay": "Auto-play",
+    "autoPlayOff": "Stop auto-play",
+    "speed": "Speed",
+    "voiceInput": "Voice input",
+    "voiceInputDisabled": "Voice input disabled",
+    "textInput": "Text input",
+    "stopRecording": "Stop recording",
+    "startRecording": "Start recording"
+  },
+  "pbl": {
+    "legacyFormat": "This PBL scene uses a legacy format. Please regenerate the course.",
+    "emptyProject": "PBL project has not been generated yet. Please create via course generation.",
+    "roleSelection": {
+      "title": "Choose Your Role",
+      "description": "Select a role to start collaborating on the project"
+    },
+    "workspace": {
+      "restart": "Restart",
+      "confirmRestart": "Reset all progress?",
+      "confirm": "Confirm",
+      "cancel": "Cancel"
+    },
+    "issueboard": {
+      "title": "Issue Board",
+      "noIssues": "No issues yet",
+      "statusDone": "Done",
+      "statusActive": "Active",
+      "statusPending": "Pending"
+    },
+    "chat": {
+      "title": "Project Discussion",
+      "currentIssue": "Current Issue",
+      "mentionHint": "Use @question to ask, @judge to submit for review",
+      "placeholder": "Type a message...",
+      "send": "Send",
+      "welcomeMessage": "Hello! I'm your Question Agent for this issue: \"{{title}}\"\n\nTo help guide your work, I've prepared some questions for you:\n\n{{questions}}\n\nFeel free to @question me anytime if you need help or clarification!",
+      "issueCompleteMessage": "Issue \"{{completed}}\" completed! Moving to next issue: \"{{next}}\"",
+      "allCompleteMessage": "🎉 All issues completed! Great work on the project!"
+    },
+    "guide": {
+      "howItWorks": "How it works",
+      "help": "Help",
+      "title": "Help",
+      "step1": {
+        "title": "Step 1: Choose a Role",
+        "desc": "After the project is generated, select a role from the list (non-system roles marked with 🟢)"
+      },
+      "step2": {
+        "title": "Step 2: Complete Issues",
+        "desc": "Each issue represents a learning task:",
+        "s1": {
+          "title": "View current Issue",
+          "desc": "Check the issue's title, description, and assignee"
+        },
+        "s2": {
+          "title": "Get guidance",
+          "example": "@question Where should I start?\n@question How do I implement this feature?",
+          "desc": "The Question Agent provides guiding questions and hints (no direct answers)"
+        },
+        "s3": {
+          "title": "Submit your work",
+          "example": "@judge I'm done, please check my Notes",
+          "desc": "The Judge Agent evaluates your work and gives feedback:",
+          "complete": "Automatically moves to the next issue",
+          "revision": "Improve based on feedback"
+        }
+      },
+      "step3": {
+        "title": "Step 3: Complete the Project",
+        "desc": "When all issues are done, the system displays \"🎉 Project Complete!\""
+      }
+    }
+  },
+  "share": {
+    "notReady": "Available after generation completes"
+  },
+  "classroom": {
+    "recentClassrooms": "Recent",
+    "today": "Today",
+    "yesterday": "Yesterday",
+    "daysAgo": "days ago",
+    "slides": "slides",
+    "nameCopied": "Name copied",
+    "deleteConfirmTitle": "Delete",
+    "delete": "Delete",
+    "rename": "Rename",
+    "renamePlaceholder": "Enter classroom name",
+    "renameFailed": "Failed to rename classroom"
+  },
+  "upload": {
+    "pdfSizeLimit": "Supports PDF files up to 50MB",
+    "generateFailed": "Failed to generate classroom, please try again",
+    "requirementPlaceholder": "Tell me anything you want to learn, e.g.\n\"Teach me Python from scratch in 30 minutes\"\n\"Explain Fourier Transform on the whiteboard\"\n\"How to play the board game Avalon\"",
+    "requirementRequired": "Please enter course requirements",
+    "fileTooLarge": "File too large. Please select a PDF file smaller than 50MB"
+  },
+  "generation": {
+    "analyzingPdf": "Analyzing PDF Document",
+    "analyzingPdfDesc": "Extracting document structure and content...",
+    "pdfLoadFailed": "Failed to load PDF file, please try again",
+    "pdfParseFailed": "PDF parsing failed",
+    "streamNotReadable": "Unable to read generation stream",
+    "generatingOutlines": "Drafting Course Outline",
+    "generatingOutlinesDesc": "Structuring the learning path...",
+    "generatingSlideContent": "Generating Page Content",
+    "generatingSlideContentDesc": "Creating slides, quizzes, and interactive content...",
+    "generatingActions": "Generating Teaching Actions",
+    "generatingActionsDesc": "Orchestrating narration, spotlights, and interactions...",
+    "generationComplete": "Generation complete!",
+    "generationFailed": "Generation failed",
+    "generatingCourse": "Generating course",
+    "openingClassroom": "Opening classroom...",
+    "outlineReady": "Course outline generated",
+    "generatingFirstPage": "Generating first page...",
+    "firstPageReady": "First page ready! Opening classroom...",
+    "speechFailed": "Speech generation failed",
+    "retryScene": "Retry",
+    "retryingScene": "Regenerating...",
+    "backToHome": "Back to Home",
+    "sessionNotFound": "Session Not Found",
+    "sessionNotFoundDesc": "Please fill in course requirements to start the generation process.",
+    "goBackAndRetry": "Go Back and Retry",
+    "classroomReady": "Your personalized AI learning environment has been generated successfully.",
+    "aiWorking": "AI Agents Working...",
+    "textTruncated": "Document text is long, using first {{n}} characters for generation",
+    "imageTruncated": "{{total}} images found, exceeding the {{max}} image limit. Extra images will use text descriptions only",
+    "agentGeneration": "Generating Classroom Roles",
+    "agentGenerationDesc": "Generating roles based on course content...",
+    "agentRevealTitle": "Your Classroom Roles",
+    "viewAgents": "View Roles",
+    "continue": "Continue",
+    "outlineRetrying": "Outline generation issue, retrying...",
+    "outlineEmptyResponse": "Model returned no valid outlines. Please check model configuration and try again",
+    "outlineGenerateFailed": "Outline generation failed, please try again later",
+    "webSearching": "Web Search",
+    "webSearchingDesc": "Searching the web for up-to-date information",
+    "webSearchFailed": "Web search failed"
+  },
+  "settings": {
+    "title": "Settings",
+    "description": "Configure application settings",
+    "language": "Language",
+    "languageDesc": "Select interface language",
+    "theme": "Theme",
+    "themeDesc": "Select theme mode (Light/Dark/System)",
+    "themeOptions": {
+      "light": "Light",
+      "dark": "Dark",
+      "system": "System"
+    },
+    "apiKey": "API Key",
+    "apiKeyDesc": "Configure your API key",
+    "apiBaseUrl": "API Endpoint URL",
+    "apiBaseUrlDesc": "Configure your API endpoint URL",
+    "apiKeyRequired": "API key cannot be empty",
+    "model": "Model Configuration",
+    "modelDesc": "Configure AI models",
+    "modelPlaceholder": "Enter or select model name",
+    "ttsModel": "TTS Model",
+    "ttsModelDesc": "Configure TTS models",
+    "ttsModelPlaceholder": "Enter or select TTS model name",
+    "ttsModelOptions": {
+      "openaiTts": "OpenAI TTS",
+      "azureTts": "Azure TTS"
+    },
+    "availableModels": "Available Models",
+    "modelSelectedViaVoice": "Model is determined by voice selection",
+    "testConnection": "Test Connection",
+    "testConnectionDesc": "Test current API configuration is available",
+    "testing": "Testing...",
+    "agentSettings": "Agent Settings",
+    "agentSettingsDesc": "Select the agents to participate in the conversation. Select 1 for single agent mode, select multiple for multi-agent collaborative mode.",
+    "agentMode": "Agent Mode",
+    "agentModePreset": "Preset",
+    "agentModeAuto": "Auto-generate",
+    "agentModeAutoDesc": "AI will automatically generate appropriate roles",
+    "autoAgentCount": "Agent Count",
+    "autoAgentCountDesc": "Number of agents to auto-generate (including teacher)",
+    "atLeastOneAgent": "Please select at least 1 agent",
+    "singleAgentMode": "Single Agent Mode",
+    "directAnswer": "Direct Answer",
+    "multiAgentMode": "Multi-Agent Mode",
+    "agentsCollaborating": "Collaborative Discussion",
+    "agentsCollaboratingCount": "{{count}} agents selected for collaborative discussion",
+    "maxTurns": "Max Discussion Turns",
+    "maxTurnsDesc": "The maximum number of discussion turns between agents (each agent completes actions and reply counts as one turn)",
+    "priority": "Priority",
+    "actions": "Actions",
+    "actionCount": "{{count}} actions",
+    "selectedAgent": "Selected Agent",
+    "selectedAgents": "Selected Agents",
+    "required": "Required",
+    "agentNames": {
+      "default-1": "AI Teacher",
+      "default-2": "AI Assistant",
+      "default-3": "Class Clown",
+      "default-4": "Curious Mind",
+      "default-5": "Note Taker",
+      "default-6": "Deep Thinker"
+    },
+    "agentRoles": {
+      "teacher": "Teacher",
+      "assistant": "Assistant",
+      "student": "Student"
+    },
+    "agentDescriptions": {
+      "default-1": "Lead teacher with clear and structured explanations",
+      "default-2": "Supports learning and helps clarify key points",
+      "default-3": "Brings humor and energy to the classroom",
+      "default-4": "Always curious, loves asking why and how",
+      "default-5": "Diligently records and organizes class notes",
+      "default-6": "Thinks deeply and explores the essence of topics"
+    },
+    "close": "Close",
+    "save": "Save",
+    "providers": "LLM",
+    "addProviderDescription": "Add custom model providers to extend available AI models",
+    "providerNames": {
+      "openai": "OpenAI",
+      "anthropic": "Claude",
+      "google": "Gemini",
+      "deepseek": "DeepSeek",
+      "qwen": "Qwen",
+      "kimi": "Kimi",
+      "minimax": "MiniMax",
+      "glm": "GLM",
+      "siliconflow": "SiliconFlow"
+    },
+    "providerTypes": {
+      "openai": "OpenAI Protocol",
+      "anthropic": "Claude Protocol",
+      "google": "Gemini Protocol"
+    },
+    "modelCount": "models",
+    "modelSingular": "model",
+    "defaultModel": "Default Model",
+    "webSearch": "Web Search",
+    "mcp": "MCP",
+    "knowledgeBase": "Knowledge Base",
+    "documentParser": "Document Parser",
+    "conversationSettings": "Conversation",
+    "keyboardShortcuts": "Shortcuts",
+    "generalSettings": "General",
+    "systemSettings": "System",
+    "addProvider": "Add",
+    "importFromClipboard": "Import from Clipboard",
+    "apiSecret": "API Key",
+    "apiHost": "Base URL",
+    "requestUrl": "Request URL",
+    "models": "Models",
+    "addModel": "New",
+    "reset": "Reset",
+    "fetch": "Fetch",
+    "connectionSuccess": "Connection successful",
+    "connectionFailed": "Connection failed",
+    "capabilities": {
+      "vision": "Vision",
+      "tools": "Tools",
+      "streaming": "Streaming"
+    },
+    "contextWindow": "Context",
+    "contextShort": "ctx",
+    "outputWindow": "Output",
+    "addProviderButton": "Add",
+    "addProviderDialog": "Add Model Provider",
+    "providerName": "Name",
+    "providerNamePlaceholder": "e.g., My OpenAI Proxy",
+    "providerNameRequired": "Please enter provider name",
+    "providerApiMode": "API Mode",
+    "apiModeOpenAI": "OpenAI Protocol",
+    "apiModeAnthropic": "Claude Protocol",
+    "apiModeGoogle": "Gemini Protocol",
+    "defaultBaseUrl": "Default Base URL",
+    "providerIcon": "Provider Icon URL",
+    "requiresApiKey": "Requires API Key",
+    "deleteProvider": "Delete Provider",
+    "deleteProviderConfirm": "Are you sure you want to delete this provider?",
+    "cannotDeleteBuiltIn": "Cannot delete built-in provider",
+    "resetToDefault": "Reset to Default",
+    "resetToDefaultDescription": "Restore model list to default configuration (API key and Base URL will be preserved)",
+    "resetConfirmDescription": "This will remove all custom models and restore the built-in default model list. API key and Base URL will be preserved.",
+    "confirmReset": "Confirm Reset",
+    "resetSuccess": "Successfully reset to default configuration",
+    "saveSuccess": "Settings saved",
+    "saveFailed": "Failed to save settings, please try again",
+    "cannotDeleteBuiltInModel": "Cannot delete built-in model",
+    "cannotEditBuiltInModel": "Cannot edit built-in model",
+    "modelIdRequired": "Please enter model ID",
+    "noModelsAvailable": "No models available for testing",
+    "providerMetadata": "Provider Metadata",
+    "editModel": "Edit Model",
+    "editModelDescription": "Edit model configuration and capabilities",
+    "addNewModel": "New Model",
+    "addNewModelDescription": "Add a new model configuration",
+    "modelId": "Model ID",
+    "modelIdPlaceholder": "e.g., gpt-4o",
+    "modelName": "Display Name",
+    "modelNamePlaceholder": "Optional",
+    "modelCapabilities": "Capabilities",
+    "advancedSettings": "Advanced Settings",
+    "contextWindowLabel": "Context Window",
+    "contextWindowPlaceholder": "e.g., 128000",
+    "outputWindowLabel": "Max Output Tokens",
+    "outputWindowPlaceholder": "e.g., 4096",
+    "testModel": "Test Model",
+    "deleteModel": "Delete",
+    "cancelEdit": "Cancel",
+    "saveModel": "Save",
+    "modelsManagementDescription": "Manage models for this provider. To select the active model, go to \"General\".",
+    "howToUse": "How to Use",
+    "step1ConfigureProvider": "Go to \"Model Providers\", select or add a provider, and configure connection settings (API key, Base URL, etc.)",
+    "step2SelectModel": "Select the model you want to use in \"Active Model\" below",
+    "step3StartUsing": "After saving, the system will use your selected model",
+    "activeModel": "Active Model",
+    "activeModelDescription": "Select the model for AI conversations and content generation",
+    "selectModel": "Select Model",
+    "searchModels": "Search models",
+    "noModelsFound": "No matching models found",
+    "noConfiguredProviders": "No configured providers",
+    "configureProvidersFirst": "Please configure provider connection settings in \"Model Providers\" on the left",
+    "currentlyUsing": "Currently using",
+    "ttsSettings": "Text-to-Speech",
+    "asrSettings": "Speech Recognition",
+    "audioSettings": "Audio Settings",
+    "ttsSection": "Text-to-Speech (TTS)",
+    "asrSection": "Automatic Speech Recognition (ASR)",
+    "ttsDescription": "TTS (Text-to-Speech) - Convert text to speech",
+    "asrDescription": "ASR (Automatic Speech Recognition) - Convert speech to text",
+    "enableTTS": "Enable Text-to-Speech",
+    "ttsEnabledDescription": "When enabled, speech audio will be generated during course creation",
+    "ttsVoiceConfigHint": "Per-agent voice can be configured in \"Classroom Role Config\" on the homepage",
+    "enableASR": "Enable Speech Recognition",
+    "asrEnabledDescription": "When enabled, students can use microphone for voice input",
+    "ttsProvider": "TTS Provider",
+    "ttsLanguageFilter": "Language Filter",
+    "allLanguages": "All Languages",
+    "ttsVoice": "Voice",
+    "ttsSpeed": "Speed",
+    "ttsBaseUrl": "Base URL",
+    "ttsApiKey": "API Key",
+    "doubaoAppId": "App ID",
+    "doubaoAccessKey": "Access Key",
+    "asrProvider": "ASR Provider",
+    "asrLanguage": "Recognition Language",
+    "asrBaseUrl": "Base URL",
+    "asrApiKey": "API Key",
+    "enterApiKey": "Enter API Key",
+    "enterCustomBaseUrl": "Enter custom Base URL",
+    "browserNativeNote": "Browser Native ASR requires no configuration and is completely free",
+    "providerOpenAITTS": "OpenAI TTS (gpt-4o-mini-tts)",
+    "providerAzureTTS": "Azure TTS",
+    "providerGLMTTS": "GLM TTS",
+    "providerQwenTTS": "Qwen TTS (Alibaba Cloud Bailian)",
+    "providerDoubaoTTS": "Doubao TTS 2.0 (Volcengine)",
+    "providerElevenLabsTTS": "ElevenLabs TTS",
+    "providerMiniMaxTTS": "MiniMax TTS",
+    "providerBrowserNativeTTS": "Browser Native TTS",
+    "providerOpenAIWhisper": "OpenAI ASR (gpt-4o-mini-transcribe)",
+    "providerBrowserNative": "Browser Native ASR",
+    "providerQwenASR": "Qwen ASR (Alibaba Cloud Bailian)",
+    "providerUnpdf": "unpdf (Built-in)",
+    "providerMinerU": "MinerU",
+    "browserNativeTTSNote": "Browser Native TTS requires no configuration and is completely free, using system built-in voices",
+    "testTTS": "Test TTS",
+    "testASR": "Test ASR",
+    "testSuccess": "Test Successful",
+    "testFailed": "Test Failed",
+    "ttsTestText": "TTS Test Text",
+    "ttsTestSuccess": "TTS test successful, audio played",
+    "ttsTestFailed": "TTS test failed",
+    "asrTestSuccess": "Speech recognition successful",
+    "asrTestFailed": "Speech recognition failed",
+    "asrResult": "Recognition Result",
+    "asrNotSupported": "Browser does not support Speech Recognition API",
+    "browserTTSNotSupported": "Browser does not support Speech Synthesis API",
+    "browserTTSNoVoices": "Current browser has no available TTS voices",
+    "microphoneAccessDenied": "Microphone access denied",
+    "microphoneAccessFailed": "Failed to access microphone",
+    "asrResultPlaceholder": "Recognition result will be displayed after recording",
+    "useThisProvider": "Use This Provider",
+    "fetchVoices": "Fetch Voice List",
+    "fetchingVoices": "Fetching...",
+    "voicesFetched": "Voices fetched",
+    "fetchVoicesFailed": "Failed to fetch voices",
+    "voiceApiKeyRequired": "API Key required",
+    "voiceBaseUrlRequired": "Base URL required",
+    "ttsTestTextPlaceholder": "Enter text to convert",
+    "ttsTestTextDefault": "Hello, this is a test speech.",
+    "startRecording": "Start Recording",
+    "stopRecording": "Stop Recording",
+    "recording": "Recording...",
+    "transcribing": "Transcribing...",
+    "transcriptionResult": "Transcription Result",
+    "noTranscriptionResult": "No transcription result",
+    "baseUrlOptional": "Base URL (Optional)",
+    "defaultValue": "Default",
+    "voiceMarin": "Recommended - Best Quality",
+    "voiceCedar": "Recommended - Best Quality",
+    "voiceAlloy": "Neutral, Balanced",
+    "voiceAsh": "Steady, Professional",
+    "voiceBallad": "Elegant, Lyrical",
+    "voiceCoral": "Warm, Friendly",
+    "voiceEcho": "Male, Clear",
+    "voiceFable": "Narrative, Vivid",
+    "voiceNova": "Female, Bright",
+    "voiceOnyx": "Male, Deep",
+    "voiceSage": "Wise, Composed",
+    "voiceShimmer": "Female, Soft",
+    "voiceVerse": "Natural, Smooth",
+    "glmVoiceTongtong": "Default voice",
+    "glmVoiceChuichui": "Chuichui voice",
+    "glmVoiceXiaochen": "Xiaochen voice",
+    "glmVoiceJam": "Jam voice",
+    "glmVoiceKazi": "Kazi voice",
+    "glmVoiceDouji": "Douji voice",
+    "glmVoiceLuodo": "Luodo voice",
+    "qwenVoiceCherry": "Sunny, warm and natural",
+    "qwenVoiceSerena": "Gentle and soft",
+    "qwenVoiceEthan": "Energetic and vibrant",
+    "qwenVoiceChelsie": "Anime virtual girlfriend",
+    "qwenVoiceMomo": "Playful and cheerful",
+    "qwenVoiceVivian": "Cute and sassy",
+    "qwenVoiceMoon": "Cool and handsome",
+    "qwenVoiceMaia": "Intellectual and gentle",
+    "qwenVoiceKai": "A SPA for your ears",
+    "qwenVoiceNofish": "Designer who can't pronounce retroflex sounds",
+    "qwenVoiceBella": "Little loli who doesn't get drunk",
+    "qwenVoiceJennifer": "Brand-level, cinematic American female voice",
+    "qwenVoiceRyan": "Fast-paced, dramatic performance",
+    "qwenVoiceKaterina": "Mature lady with memorable rhythm",
+    "qwenVoiceAiden": "American boy who masters cooking",
+    "qwenVoiceEldricSage": "Steady and wise elder",
+    "qwenVoiceMia": "Gentle as spring water, well-behaved as snow",
+    "qwenVoiceMochi": "Smart little adult with childlike innocence",
+    "qwenVoiceBellona": "Loud voice, clear pronunciation, vivid characters",
+    "qwenVoiceVincent": "Unique hoarse voice telling tales of war and honor",
+    "qwenVoiceBunny": "Super cute loli",
+    "qwenVoiceNeil": "Professional news anchor",
+    "qwenVoiceElias": "Professional instructor",
+    "qwenVoiceArthur": "Simple voice soaked by years and dry tobacco",
+    "qwenVoiceNini": "Soft and sticky voice like glutinous rice cake",
+    "qwenVoiceEbona": "Her whisper is like a rusty key",
+    "qwenVoiceSeren": "Gentle and soothing voice to help you sleep",
+    "qwenVoicePip": "Naughty but full of childlike innocence",
+    "qwenVoiceStella": "Sweet confused girl voice that becomes just when shouting",
+    "qwenVoiceBodega": "Enthusiastic Spanish uncle",
+    "qwenVoiceSonrisa": "Enthusiastic Latin American lady",
+    "qwenVoiceAlek": "Cold of battle nation, warm under woolen coat",
+    "qwenVoiceDolce": "Lazy Italian uncle",
+    "qwenVoiceSohee": "Gentle, cheerful Korean unnie",
+    "qwenVoiceOnoAnna": "Mischievous childhood friend",
+    "qwenVoiceLenn": "Rational German youth who wears suit and listens to post-punk",
+    "qwenVoiceEmilien": "Romantic French big brother",
+    "qwenVoiceAndre": "Magnetic, natural and calm male voice",
+    "qwenVoiceRadioGol": "Football poet Rádio Gol!",
+    "qwenVoiceJada": "Lively Shanghai lady",
+    "qwenVoiceDylan": "Beijing boy",
+    "qwenVoiceLi": "Patient yoga teacher",
+    "qwenVoiceMarcus": "Broad face, short words, solid heart - old Shaanxi taste",
+    "qwenVoiceRoy": "Humorous and straightforward Taiwanese boy",
+    "qwenVoicePeter": "Tianjin cross-talk professional supporter",
+    "qwenVoiceSunny": "Sweet Sichuan girl",
+    "qwenVoiceEric": "Chengdu gentleman",
+    "qwenVoiceRocky": "Humorous Hong Kong guy",
+    "qwenVoiceKiki": "Sweet Hong Kong girl",
+    "lang_auto": "Auto Detect",
+    "lang_zh": "中文",
+    "lang_yue": "粤語",
+    "lang_en": "English",
+    "lang_ja": "日本語",
+    "lang_ko": "한국어",
+    "lang_es": "Español",
+    "lang_fr": "Français",
+    "lang_de": "Deutsch",
+    "lang_ru": "Русский",
+    "lang_ar": "العربية",
+    "lang_pt": "Português",
+    "lang_it": "Italiano",
+    "lang_af": "Afrikaans",
+    "lang_hy": "Հայերեն",
+    "lang_az": "Azərbaycan",
+    "lang_be": "Беларуская",
+    "lang_bs": "Bosanski",
+    "lang_bg": "Български",
+    "lang_ca": "Català",
+    "lang_hr": "Hrvatski",
+    "lang_cs": "Čeština",
+    "lang_da": "Dansk",
+    "lang_nl": "Nederlands",
+    "lang_et": "Eesti",
+    "lang_fi": "Suomi",
+    "lang_gl": "Galego",
+    "lang_el": "Ελληνικά",
+    "lang_he": "עברית",
+    "lang_hi": "हिन्दी",
+    "lang_hu": "Magyar",
+    "lang_is": "Íslenska",
+    "lang_id": "Bahasa Indonesia",
+    "lang_kn": "ಕನ್ನಡ",
+    "lang_kk": "Қазақша",
+    "lang_lv": "Latviešu",
+    "lang_lt": "Lietuvių",
+    "lang_mk": "Македонски",
+    "lang_ms": "Bahasa Melayu",
+    "lang_mr": "मराठी",
+    "lang_mi": "Te Reo Māori",
+    "lang_ne": "नेपाली",
+    "lang_no": "Norsk",
+    "lang_fa": "فارسی",
+    "lang_pl": "Polski",
+    "lang_ro": "Română",
+    "lang_sr": "Српски",
+    "lang_sk": "Slovenčina",
+    "lang_sl": "Slovenščina",
+    "lang_sw": "Kiswahili",
+    "lang_sv": "Svenska",
+    "lang_tl": "Tagalog",
+    "lang_fil": "Filipino",
+    "lang_ta": "தமிழ்",
+    "lang_th": "ไทย",
+    "lang_tr": "Türkçe",
+    "lang_uk": "Українська",
+    "lang_ur": "اردو",
+    "lang_vi": "Tiếng Việt",
+    "lang_cy": "Cymraeg",
+    "lang_zh-CN": "中文（简体，中国）",
+    "lang_zh-TW": "中文（繁體，台灣）",
+    "lang_zh-HK": "粵語（香港）",
+    "lang_yue-Hant-HK": "粵語（繁體）",
+    "lang_en-US": "English (United States)",
+    "lang_en-GB": "English (United Kingdom)",
+    "lang_en-AU": "English (Australia)",
+    "lang_en-CA": "English (Canada)",
+    "lang_en-IN": "English (India)",
+    "lang_en-NZ": "English (New Zealand)",
+    "lang_en-ZA": "English (South Africa)",
+    "lang_ja-JP": "日本語（日本）",
+    "lang_ko-KR": "한국어（대한민국）",
+    "lang_de-DE": "Deutsch (Deutschland)",
+    "lang_fr-FR": "Français (France)",
+    "lang_es-ES": "Español (España)",
+    "lang_es-MX": "Español (México)",
+    "lang_es-AR": "Español (Argentina)",
+    "lang_es-CO": "Español (Colombia)",
+    "lang_it-IT": "Italiano (Italia)",
+    "lang_pt-BR": "Português (Brasil)",
+    "lang_pt-PT": "Português (Portugal)",
+    "lang_ru-RU": "Русский (Россия)",
+    "lang_nl-NL": "Nederlands (Nederland)",
+    "lang_pl-PL": "Polski (Polska)",
+    "lang_cs-CZ": "Čeština (Česko)",
+    "lang_da-DK": "Dansk (Danmark)",
+    "lang_fi-FI": "Suomi (Suomi)",
+    "lang_sv-SE": "Svenska (Sverige)",
+    "lang_no-NO": "Norsk (Norge)",
+    "lang_tr-TR": "Türkçe (Türkiye)",
+    "lang_el-GR": "Ελληνικά (Ελλάδα)",
+    "lang_hu-HU": "Magyar (Magyarország)",
+    "lang_ro-RO": "Română (România)",
+    "lang_sk-SK": "Slovenčina (Slovensko)",
+    "lang_bg-BG": "Български (България)",
+    "lang_hr-HR": "Hrvatski (Hrvatska)",
+    "lang_ca-ES": "Català (Espanya)",
+    "lang_ar-SA": "العربية (السعودية)",
+    "lang_ar-EG": "العربية (مصر)",
+    "lang_he-IL": "עברית (ישראל)",
+    "lang_hi-IN": "हिन्दी (भारत)",
+    "lang_th-TH": "ไทย (ประเทศไทย)",
+    "lang_vi-VN": "Tiếng Việt (Việt Nam)",
+    "lang_id-ID": "Bahasa Indonesia (Indonesia)",
+    "lang_ms-MY": "Bahasa Melayu (Malaysia)",
+    "lang_fil-PH": "Filipino (Pilipinas)",
+    "lang_af-ZA": "Afrikaans (Suid-Afrika)",
+    "lang_uk-UA": "Українська (Україна)",
+    "pdfSettings": "PDF Parsing",
+    "pdfParsingSettings": "PDF Parsing Settings",
+    "pdfDescription": "Choose PDF parsing engine with support for text extraction, image processing, and table recognition",
+    "pdfProvider": "PDF Parser",
+    "pdfFeatures": "Supported Features",
+    "pdfApiKey": "API Key",
+    "pdfBaseUrl": "Base URL",
+    "mineruDescription": "MinerU is a commercial PDF parsing service that supports advanced features such as table extraction, formula recognition, and layout analysis.",
+    "mineruApiKeyRequired": "You need to apply for an API Key on the MinerU website before use.",
+    "mineruWarning": "Warning",
+    "mineruCostWarning": "MinerU is a commercial service and may incur fees. Please check the MinerU website for pricing details.",
+    "enterMinerUApiKey": "Enter MinerU API Key",
+    "mineruLocalDescription": "MinerU supports local deployment with advanced PDF parsing (tables, formulas, layout analysis). Requires deploying MinerU service first.",
+    "mineruServerAddress": "Local MinerU server address (e.g., http://localhost:8080)",
+    "mineruApiKeyOptional": "Only required if server has authentication enabled",
+    "optionalApiKey": "Optional API Key",
+    "featureText": "Text Extraction",
+    "featureImages": "Image Extraction",
+    "featureTables": "Table Extraction",
+    "featureFormulas": "Formula Recognition",
+    "featureLayoutAnalysis": "Layout Analysis",
+    "featureMetadata": "Metadata",
+    "enableImageGeneration": "Enable AI Image Generation",
+    "imageGenerationDisabledHint": "When enabled, images will be auto-generated during course creation",
+    "imageSettings": "Image Generation",
+    "imageSection": "Text to Image",
+    "imageProvider": "Image Generation Provider",
+    "imageModel": "Image Generation Model",
+    "providerSeedream": "Seedream (ByteDance)",
+    "providerQwenImage": "Qwen Image (Alibaba)",
+    "providerNanoBanana": "Nano Banana (Gemini)",
+    "providerMiniMaxImage": "MiniMax Image",
+    "providerGrokImage": "Grok Image (xAI)",
+    "testImageGeneration": "Test Image Generation",
+    "testImageConnectivity": "Test Connection",
+    "imageConnectivitySuccess": "Image service connected successfully",
+    "imageConnectivityFailed": "Image service connection failed",
+    "imageTestSuccess": "Image generation test succeeded",
+    "imageTestFailed": "Image generation test failed",
+    "imageTestPromptPlaceholder": "Enter image description to test",
+    "imageTestPromptDefault": "A cute cat sitting on a desk",
+    "imageGenerating": "Generating image...",
+    "imageGenerationFailed": "Image generation failed",
+    "enableVideoGeneration": "Enable AI Video Generation",
+    "videoGenerationDisabledHint": "When enabled, videos will be auto-generated during course creation",
+    "videoSettings": "Video Generation",
+    "videoSection": "Text to Video",
+    "videoProvider": "Video Generation Provider",
+    "videoModel": "Video Generation Model",
+    "providerSeedance": "Seedance (ByteDance)",
+    "providerKling": "Kling (Kuaishou)",
+    "providerVeo": "Veo (Google)",
+    "providerSora": "Sora (OpenAI)",
+    "providerMiniMaxVideo": "MiniMax Video",
+    "providerGrokVideo": "Grok Video (xAI)",
+    "testVideoGeneration": "Test Video Generation",
+    "testVideoConnectivity": "Test Connection",
+    "videoConnectivitySuccess": "Video service connected successfully",
+    "videoConnectivityFailed": "Video service connection failed",
+    "testingConnection": "Testing...",
+    "videoTestSuccess": "Video generation test succeeded",
+    "videoTestFailed": "Video generation test failed",
+    "videoTestPromptDefault": "A cute cat walking on a desk",
+    "videoGenerating": "Generating video (est. 1-2 min)...",
+    "videoGenerationWarning": "Video generation usually takes 1-2 minutes, please be patient",
+    "mediaRetry": "Retry",
+    "mediaContentSensitive": "Sorry, this content triggered a safety check.",
+    "mediaGenerationDisabled": "Generation disabled in settings",
+    "singleAgent": "Single Agent",
+    "multiAgent": "Multi-Agent",
+    "selectAgents": "Select Agents",
+    "noVisionWarning": "Current model does not support vision. Images can still be placed in slides, but the model cannot understand image content to optimize selection and layout",
+    "serverConfigured": "Server",
+    "serverConfiguredNotice": "Admin has configured an API key for this provider on the server. You can use it directly or enter your own key to override.",
+    "optionalOverride": "Optional — leave empty to use server config",
+    "setupNeeded": "Setup required",
+    "modelNotConfigured": "Please select a model to get started",
+    "dangerZone": "Danger Zone",
+    "clearCache": "Clear Local Cache",
+    "clearCacheDescription": "Delete all locally stored data, including classroom records, chat history, audio cache, and app settings. This action cannot be undone.",
+    "clearCacheConfirmTitle": "Are you sure you want to clear all cache?",
+    "clearCacheConfirmDescription": "This will permanently delete all of the following data and cannot be recovered:",
+    "clearCacheConfirmItems": "Classrooms & scenes, Chat history, Audio & image cache, App settings & preferences",
+    "clearCacheConfirmInput": "Type \"DELETE\" to continue",
+    "clearCacheConfirmPhrase": "DELETE",
+    "clearCacheButton": "Permanently Delete All Data",
+    "clearCacheSuccess": "Cache cleared, page will refresh shortly",
+    "clearCacheFailed": "Failed to clear cache, please try again",
+    "webSearchSettings": "Web Search",
+    "webSearchApiKey": "Tavily API Key",
+    "webSearchApiKeyPlaceholder": "Enter your Tavily API Key",
+    "webSearchApiKeyPlaceholderServer": "Server key configured, optionally override",
+    "webSearchApiKeyHint": "Get an API key from tavily.com for web search",
+    "webSearchBaseUrl": "Base URL",
+    "webSearchServerConfigured": "Server-side Tavily API key is configured",
+    "optional": "Optional"
+  },
+  "profile": {
+    "title": "Profile",
+    "defaultNickname": "Learner",
+    "chooseAvatar": "Choose Avatar",
+    "uploadAvatar": "Upload",
+    "bioPlaceholder": "Tell us about yourself — the AI teacher will personalize lessons for you...",
+    "avatarHint": "Your avatar will appear in classroom discussions and chats",
+    "fileTooLarge": "Image too large — please choose one under 5 MB",
+    "invalidFileType": "Please select an image file",
+    "editTooltip": "Click to edit profile"
+  },
+  "media": {
+    "imageCapability": "Image Generation",
+    "imageHint": "Generate images in slides",
+    "videoCapability": "Video Generation",
+    "videoHint": "Generate videos in slides",
+    "ttsCapability": "Text-to-Speech",
+    "ttsHint": "AI teacher speaks aloud",
+    "asrCapability": "Speech Recognition",
+    "asrHint": "Voice input for discussion",
+    "provider": "Provider",
+    "model": "Model",
+    "voice": "Voice",
+    "speed": "Speed",
+    "language": "Language"
+  }
+}
diff --git a/lib/i18n/locales/zh-CN.json b/lib/i18n/locales/zh-CN.json
new file mode 100644
index 000000000..82b07bb38
--- /dev/null
+++ b/lib/i18n/locales/zh-CN.json
@@ -0,0 +1,877 @@
+{
+  "common": {
+    "you": "你",
+    "confirm": "确定",
+    "cancel": "取消",
+    "loading": "加载中..."
+  },
+  "home": {
+    "slogan": "Generative Learning in Multi-Agent Interactive Classroom",
+    "greetingWithName": "嗨，{{name}}"
+  },
+  "toolbar": {
+    "languageHint": "课程将以此语言生成",
+    "pdfParser": "解析器",
+    "pdfUpload": "上传 PDF",
+    "removePdf": "移除文件",
+    "webSearchOn": "已开启",
+    "webSearchOff": "点击开启",
+    "webSearchDesc": "生成前搜索网络获取最新资料，让内容更丰富准确",
+    "webSearchProvider": "搜索引擎",
+    "webSearchNoProvider": "请在设置中配置搜索引擎 API Key",
+    "selectProvider": "选择模型服务商",
+    "configureProvider": "配置模型",
+    "configureProviderHint": "请先配置至少一个模型服务商才能生成课程",
+    "enterClassroom": "进入课堂",
+    "advancedSettings": "高级设置",
+    "ttsTitle": "语音合成",
+    "ttsHint": "选择 AI 教师的朗读音色",
+    "ttsPreview": "试听",
+    "ttsPreviewing": "播放中..."
+  },
+  "export": {
+    "pptx": "导出 PPTX",
+    "resourcePack": "导出教学资源包",
+    "resourcePackDesc": "PPTX + 交互式页面",
+    "exporting": "正在导出...",
+    "exportSuccess": "导出成功",
+    "exportFailed": "导出失败"
+  },
+  "chat": {
+    "lecture": "授课",
+    "noConversations": "暂无对话",
+    "startConversation": "输入消息开始对话",
+    "noMessages": "暂无消息",
+    "ended": "已结束",
+    "unknown": "未知",
+    "stopDiscussion": "结束讨论",
+    "endQA": "结束问答",
+    "tabs": {
+      "lecture": "笔记",
+      "chat": "对话"
+    },
+    "lectureNotes": {
+      "empty": "播放课程后，笔记将在此显示",
+      "emptyHint": "点击播放按钮开始授课",
+      "pageLabel": "第 {{n}} 页",
+      "currentPage": "当前页"
+    },
+    "badge": {
+      "qa": "Q&A",
+      "discussion": "讨论",
+      "lecture": "授课"
+    }
+  },
+  "actions": {
+    "names": {
+      "spotlight": "聚光灯",
+      "laser": "激光笔",
+      "wb_open": "打开白板",
+      "wb_draw_text": "白板文本",
+      "wb_draw_shape": "白板形状",
+      "wb_draw_chart": "白板图表",
+      "wb_draw_latex": "白板公式",
+      "wb_draw_table": "白板表格",
+      "wb_draw_line": "白板线条",
+      "wb_clear": "清空白板",
+      "wb_delete": "删除元素",
+      "wb_close": "关闭白板",
+      "discussion": "课堂讨论"
+    },
+    "status": {
+      "inputStreaming": "等待中",
+      "inputAvailable": "执行中",
+      "outputAvailable": "已完成",
+      "outputError": "错误",
+      "outputDenied": "已拒绝",
+      "running": "执行中",
+      "result": "已完成",
+      "error": "错误"
+    }
+  },
+  "agentBar": {
+    "readyToLearn": "准备好一起学习了吗？",
+    "expandedTitle": "课堂角色配置",
+    "configTooltip": "点击配置课堂角色",
+    "voiceLabel": "音色",
+    "voiceLoading": "加载中...",
+    "voiceAutoAssign": "音色将自动分配"
+  },
+  "proactiveCard": {
+    "discussion": "讨论",
+    "join": "加入讨论",
+    "skip": "跳过",
+    "pause": "暂停",
+    "resume": "继续"
+  },
+  "voice": {
+    "startListening": "语音输入",
+    "stopListening": "停止录音"
+  },
+  "stage": {
+    "currentScene": "当前场景",
+    "generating": "生成中...",
+    "paused": "已暂停",
+    "generationFailed": "生成失败",
+    "confirmSwitchTitle": "切换页面",
+    "confirmSwitchMessage": "当前话题正在进行中，切换页面将结束当前话题。确定要切换吗？",
+    "generatingNextPage": "场景正在生成，请稍候...",
+    "fullscreen": "全屏",
+    "exitFullscreen": "退出全屏"
+  },
+  "whiteboard": {
+    "title": "互动白板",
+    "open": "打开白板",
+    "clear": "清空白板",
+    "minimize": "最小化白板",
+    "ready": "白板已就绪",
+    "readyHint": "AI 添加元素后将在此显示",
+    "clearSuccess": "白板已清空",
+    "clearError": "清空白板失败：",
+    "resetView": "重置视图",
+    "restoreError": "恢复白板失败：",
+    "history": "历史记录",
+    "restore": "恢复",
+    "noHistory": "暂无历史记录",
+    "restored": "已恢复白板内容",
+    "elementCount": "{{count}} 个元素"
+  },
+  "quiz": {
+    "title": "随堂测验",
+    "subtitle": "检测你的学习成果",
+    "questionsCount": "道题",
+    "totalPrefix": "共",
+    "pointsSuffix": "分",
+    "startQuiz": "开始答题",
+    "multipleChoiceHint": "（多选题，请选择所有正确答案）",
+    "inputPlaceholder": "请在此输入你的回答...",
+    "charCount": "字",
+    "yourAnswer": "你的回答：",
+    "notAnswered": "未作答",
+    "aiComment": "AI 点评",
+    "singleChoice": "单选",
+    "multipleChoice": "多选",
+    "shortAnswer": "简答",
+    "analysis": "解析：",
+    "excellent": "优秀！",
+    "keepGoing": "继续加油！",
+    "needsReview": "需要复习",
+    "correct": "正确",
+    "incorrect": "错误",
+    "answering": "答题中",
+    "submitAnswers": "提交答案",
+    "aiGrading": "AI 正在批改中...",
+    "aiGradingWait": "请稍候，正在分析你的答案",
+    "quizReport": "答题报告",
+    "retry": "重新答题"
+  },
+  "roundtable": {
+    "teacher": "教师",
+    "you": "你",
+    "inputPlaceholder": "输入你的消息...",
+    "listening": "录音中...",
+    "processing": "处理中...",
+    "noSpeechDetected": "未检测到语音，请重试",
+    "discussionEnded": "讨论已结束",
+    "qaEnded": "问答已结束",
+    "thinking": "思考中",
+    "yourTurn": "轮到你发言了",
+    "stopDiscussion": "结束讨论",
+    "autoPlay": "自动播放",
+    "autoPlayOff": "关闭自动播放",
+    "speed": "倍速",
+    "voiceInput": "语音输入",
+    "voiceInputDisabled": "语音输入已禁用",
+    "textInput": "文字输入",
+    "stopRecording": "停止录音",
+    "startRecording": "开始录音"
+  },
+  "pbl": {
+    "legacyFormat": "此PBL场景使用旧格式，请重新生成课程",
+    "emptyProject": "PBL项目尚未生成，请通过课程生成创建",
+    "roleSelection": {
+      "title": "选择你的角色",
+      "description": "选择一个角色开始项目协作"
+    },
+    "workspace": {
+      "restart": "重新开始",
+      "confirmRestart": "确定重置进度？",
+      "confirm": "确定",
+      "cancel": "取消"
+    },
+    "issueboard": {
+      "title": "任务看板",
+      "noIssues": "暂无任务",
+      "statusDone": "已完成",
+      "statusActive": "进行中",
+      "statusPending": "待处理"
+    },
+    "chat": {
+      "title": "项目讨论",
+      "currentIssue": "当前任务",
+      "mentionHint": "使用 @question 提问，@judge 提交评审",
+      "placeholder": "输入消息...",
+      "send": "发送",
+      "welcomeMessage": "你好！我是本任务的提问助手，当前任务：「{{title}}」\n\n为了帮助你开展工作，我准备了一些引导问题：\n\n{{questions}}\n\n随时可以 @question 向我提问！",
+      "issueCompleteMessage": "任务「{{completed}}」已完成！进入下一个任务：「{{next}}」",
+      "allCompleteMessage": "🎉 所有任务都已完成！项目做得很棒！"
+    },
+    "guide": {
+      "howItWorks": "如何参与项目",
+      "help": "使用帮助",
+      "title": "使用帮助",
+      "step1": {
+        "title": "第一步：选择角色",
+        "desc": "项目生成后，从角色列表中选择一个角色（标记为🟢的非系统角色）"
+      },
+      "step2": {
+        "title": "第二步：完成任务",
+        "desc": "每个任务代表一个学习目标：",
+        "s1": {
+          "title": "查看当前任务",
+          "desc": "查看任务的标题、描述、负责人"
+        },
+        "s2": {
+          "title": "获取指导",
+          "example": "@question 我应该从哪里开始？\n@question 如何实现这个功能？",
+          "desc": "提问助手会提供引导性问题和提示（不直接给答案）"
+        },
+        "s3": {
+          "title": "提交作品",
+          "example": "@judge 我已经完成了，请检查",
+          "desc": "评审助手会评估你的工作并给出反馈：",
+          "complete": "自动进入下一个任务",
+          "revision": "根据反馈改进"
+        }
+      },
+      "step3": {
+        "title": "第三步：完成项目",
+        "desc": "所有任务完成后，系统会显示「🎉 项目已完成！」"
+      }
+    }
+  },
+  "share": {
+    "notReady": "生成完成后可分享"
+  },
+  "classroom": {
+    "recentClassrooms": "最近学习",
+    "today": "今天",
+    "yesterday": "昨天",
+    "daysAgo": "天前",
+    "slides": "页",
+    "nameCopied": "课堂名称已复制",
+    "deleteConfirmTitle": "删除课堂",
+    "delete": "删除",
+    "rename": "重命名",
+    "renamePlaceholder": "输入课堂名称",
+    "renameFailed": "重命名失败"
+  },
+  "upload": {
+    "pdfSizeLimit": "支持最大50MB的PDF文件",
+    "generateFailed": "生成课堂失败，请重试",
+    "requirementPlaceholder": "输入你想学的任何内容，例如：\n「从零学 Python，30 分钟写出第一个程序」\n「用白板给我讲解傅里叶变换」\n「阿瓦隆桌游怎么玩」",
+    "requirementRequired": "请输入课程需求",
+    "fileTooLarge": "文件过大，请选择小于50MB的PDF文件"
+  },
+  "generation": {
+    "analyzingPdf": "解析 PDF 文档",
+    "analyzingPdfDesc": "正在提取文档结构和内容...",
+    "pdfLoadFailed": "无法加载 PDF 文件，请重试",
+    "pdfParseFailed": "PDF 解析失败",
+    "streamNotReadable": "无法读取生成数据流",
+    "generatingOutlines": "生成课程大纲",
+    "generatingOutlinesDesc": "正在构建学习路径...",
+    "generatingSlideContent": "生成页面内容",
+    "generatingSlideContentDesc": "正在创建幻灯片、测验和互动内容...",
+    "generatingActions": "生成教学动作",
+    "generatingActionsDesc": "正在编排讲解、聚焦和互动流程...",
+    "generationComplete": "生成完成！",
+    "generationFailed": "生成失败",
+    "generatingCourse": "正在生成课程",
+    "openingClassroom": "即将打开课堂...",
+    "outlineReady": "课程大纲已生成",
+    "generatingFirstPage": "首页内容生成中...",
+    "firstPageReady": "首页已就绪！正在打开课堂...",
+    "speechFailed": "语音合成失败",
+    "retryScene": "重试生成",
+    "retryingScene": "正在重新生成...",
+    "backToHome": "返回首页",
+    "sessionNotFound": "未找到生成会话",
+    "sessionNotFoundDesc": "请先填写课程需求开始生成流程。",
+    "goBackAndRetry": "返回重试",
+    "classroomReady": "你的个性化AI学习环境已成功生成。",
+    "aiWorking": "AI智能体工作中...",
+    "textTruncated": "文档文本较长，已截取前 {{n}} 字符用于生成",
+    "imageTruncated": "文档含 {{total}} 张图片，超出上限 {{max}} 张，多余图片将仅以文字描述传递",
+    "agentGeneration": "生成课堂角色",
+    "agentGenerationDesc": "正在根据课程内容生成角色...",
+    "agentRevealTitle": "你的课堂角色",
+    "viewAgents": "查看角色",
+    "continue": "继续",
+    "outlineRetrying": "大纲生成异常，正在重试...",
+    "outlineEmptyResponse": "模型未返回有效的大纲内容，请检查模型配置后重试",
+    "outlineGenerateFailed": "大纲生成失败，请稍后重试",
+    "webSearching": "网络搜索",
+    "webSearchingDesc": "正在搜索网络获取最新资料",
+    "webSearchFailed": "网络搜索失败"
+  },
+  "settings": {
+    "title": "设置",
+    "description": "配置应用程序设置",
+    "language": "语言",
+    "languageDesc": "选择界面语言",
+    "theme": "主题",
+    "themeDesc": "选择主题模式（浅色/深色/跟随系统）",
+    "themeOptions": {
+      "light": "浅色",
+      "dark": "深色",
+      "system": "跟随系统"
+    },
+    "apiKey": "API密钥",
+    "apiKeyDesc": "配置你的API密钥",
+    "apiBaseUrl": "API端点地址",
+    "apiBaseUrlDesc": "配置你的API端点地址",
+    "apiKeyRequired": "API密钥不能为空",
+    "model": "模型配置",
+    "modelDesc": "配置AI模型",
+    "modelPlaceholder": "输入或选择模型名称",
+    "ttsModel": "TTS模型",
+    "ttsModelDesc": "配置TTS模型",
+    "ttsModelPlaceholder": "输入或选择TTS模型名称",
+    "ttsModelOptions": {
+      "openaiTts": "OpenAI TTS",
+      "azureTts": "Azure TTS"
+    },
+    "availableModels": "可用模型",
+    "modelSelectedViaVoice": "模型随音色选择自动确定",
+    "testConnection": "测试连接",
+    "testConnectionDesc": "测试当前API配置是否可用",
+    "testing": "测试中...",
+    "agentSettings": "智能体设置",
+    "agentSettingsDesc": "选择参与对话的智能体。选择1个为单智能体模式，选择多个为多智能体协作模式。",
+    "agentMode": "智能体模式",
+    "agentModePreset": "预设模式",
+    "agentModeAuto": "自动生成",
+    "agentModeAutoDesc": "AI 将根据课程内容自动生成适合的课堂角色",
+    "autoAgentCount": "生成数量",
+    "autoAgentCountDesc": "自动生成的角色数量（包含教师）",
+    "atLeastOneAgent": "请至少选择1个智能体",
+    "singleAgentMode": "单智能体模式",
+    "directAnswer": "直接回答",
+    "multiAgentMode": "多智能体模式",
+    "agentsCollaborating": "协作讨论",
+    "agentsCollaboratingCount": "已选择 {{count}} 个智能体协作讨论",
+    "maxTurns": "最大讨论轮数",
+    "maxTurnsDesc": "智能体之间最多讨论多少轮（每个智能体完成动作并回复算一轮）",
+    "priority": "优先级",
+    "actions": "动作",
+    "actionCount": "{{count}} 个动作",
+    "selectedAgent": "选中的智能体",
+    "selectedAgents": "选中的智能体",
+    "required": "必选",
+    "agentNames": {
+      "default-1": "AI教师",
+      "default-2": "AI助教",
+      "default-3": "显眼包",
+      "default-4": "好奇宝宝",
+      "default-5": "笔记员",
+      "default-6": "思考者"
+    },
+    "agentRoles": {
+      "teacher": "教师",
+      "assistant": "助教",
+      "student": "学生"
+    },
+    "agentDescriptions": {
+      "default-1": "主讲教师，清晰有条理地讲解知识",
+      "default-2": "辅助讲解，帮助同学理解重点",
+      "default-3": "活跃气氛，用幽默让课堂更有趣",
+      "default-4": "充满好奇心，总爱追问为什么",
+      "default-5": "认真记录，整理课堂重点笔记",
+      "default-6": "深入思考，喜欢探讨问题本质"
+    },
+    "close": "关闭",
+    "save": "保存",
+    "providers": "语言模型",
+    "addProviderDescription": "添加自定义模型提供方以扩展可用的AI模型",
+    "providerNames": {
+      "openai": "OpenAI",
+      "anthropic": "Claude",
+      "google": "Gemini",
+      "deepseek": "DeepSeek",
+      "qwen": "通义千问",
+      "kimi": "Kimi",
+      "minimax": "MiniMax",
+      "glm": "GLM",
+      "siliconflow": "硅基流动"
+    },
+    "providerTypes": {
+      "openai": "OpenAI 协议",
+      "anthropic": "Claude 协议",
+      "google": "Gemini 协议"
+    },
+    "modelCount": "个模型",
+    "modelSingular": "个模型",
+    "defaultModel": "默认模型",
+    "webSearch": "联网搜索",
+    "mcp": "MCP",
+    "knowledgeBase": "知识库",
+    "documentParser": "文档解析器",
+    "conversationSettings": "对话设置",
+    "keyboardShortcuts": "键盘快捷键",
+    "generalSettings": "常规设置",
+    "systemSettings": "系统设置",
+    "addProvider": "添加",
+    "importFromClipboard": "从剪贴板导入",
+    "apiSecret": "API 密钥",
+    "apiHost": "Base URL",
+    "requestUrl": "请求地址",
+    "models": "模型",
+    "addModel": "新建",
+    "reset": "重置",
+    "fetch": "获取",
+    "connectionSuccess": "连接成功",
+    "connectionFailed": "连接失败",
+    "capabilities": {
+      "vision": "视觉",
+      "tools": "工具",
+      "streaming": "流式"
+    },
+    "contextWindow": "上下文",
+    "contextShort": "上下文",
+    "outputWindow": "输出",
+    "addProviderButton": "添加",
+    "addProviderDialog": "添加模型提供方",
+    "providerName": "名称",
+    "providerNamePlaceholder": "例如：我的OpenAI代理",
+    "providerNameRequired": "请输入提供方名称",
+    "providerApiMode": "API 模式",
+    "apiModeOpenAI": "OpenAI 协议",
+    "apiModeAnthropic": "Claude 协议",
+    "apiModeGoogle": "Gemini 协议",
+    "defaultBaseUrl": "默认 Base URL",
+    "providerIcon": "Provider 图标 URL",
+    "requiresApiKey": "需要 API 密钥",
+    "deleteProvider": "删除提供方",
+    "deleteProviderConfirm": "确定要删除此提供方吗？",
+    "cannotDeleteBuiltIn": "无法删除内置提供方",
+    "resetToDefault": "重置为默认配置",
+    "resetToDefaultDescription": "将模型列表恢复到默认状态（保留 API 密钥和 Base URL）",
+    "resetConfirmDescription": "此操作将清除所有自定义模型，恢复到内置的默认模型列表。API 密钥和 Base URL 将被保留。",
+    "confirmReset": "确认重置",
+    "resetSuccess": "已成功重置为默认配置",
+    "saveSuccess": "配置已保存",
+    "saveFailed": "保存失败，请重试",
+    "cannotDeleteBuiltInModel": "无法删除内置模型",
+    "cannotEditBuiltInModel": "无法编辑内置模型",
+    "modelIdRequired": "请输入模型 ID",
+    "noModelsAvailable": "没有可用于测试的模型",
+    "providerMetadata": "Provider 元数据",
+    "editModel": "编辑模型",
+    "editModelDescription": "编辑模型配置和能力",
+    "addNewModel": "新建模型",
+    "addNewModelDescription": "添加新的模型配置",
+    "modelId": "模型ID",
+    "modelIdPlaceholder": "例如：gpt-4o",
+    "modelName": "显示名称",
+    "modelNamePlaceholder": "可选",
+    "modelCapabilities": "能力",
+    "advancedSettings": "高级设置",
+    "contextWindowLabel": "上下文窗口",
+    "contextWindowPlaceholder": "例如 128000",
+    "outputWindowLabel": "最大输出Token数",
+    "outputWindowPlaceholder": "例如 4096",
+    "testModel": "测试模型",
+    "deleteModel": "删除",
+    "cancelEdit": "取消",
+    "saveModel": "保存",
+    "modelsManagementDescription": "在此管理该提供方的模型列表。若需选择使用的模型，请前往\"常规设置\"。",
+    "howToUse": "使用说明",
+    "step1ConfigureProvider": "前往\"模型提供方\"页面，选择或添加一个提供方，配置连接信息（API 密钥、Base URL 等）",
+    "step2SelectModel": "在下方\"使用模型\"中选择要使用的模型",
+    "step3StartUsing": "保存设置后，系统将使用您选择的模型",
+    "activeModel": "使用模型",
+    "activeModelDescription": "选择当前用于 AI 对话和内容生成的模型",
+    "selectModel": "选择模型",
+    "searchModels": "搜索模型",
+    "noModelsFound": "未找到匹配的模型",
+    "noConfiguredProviders": "暂无已配置的提供方",
+    "configureProvidersFirst": "请先在左侧\"模型提供方\"中配置提供方连接信息",
+    "currentlyUsing": "当前使用",
+    "ttsSettings": "语音合成",
+    "asrSettings": "语音识别",
+    "audioSettings": "音频设置",
+    "ttsSection": "文字转语音 (TTS)",
+    "asrSection": "语音识别 (ASR)",
+    "ttsDescription": "TTS (Text-to-Speech) - 将文字转换为语音",
+    "asrDescription": "ASR (Automatic Speech Recognition) - 将语音转换为文字",
+    "enableTTS": "启用语音合成",
+    "ttsEnabledDescription": "开启后，课程生成时将自动合成语音",
+    "ttsVoiceConfigHint": "每个 Agent 的音色可在首页「课堂角色配置」中设置",
+    "enableASR": "启用语音识别",
+    "asrEnabledDescription": "开启后，学生可使用麦克风进行语音输入",
+    "ttsProvider": "TTS 提供商",
+    "ttsLanguageFilter": "语言筛选",
+    "allLanguages": "全部语言",
+    "ttsVoice": "音色",
+    "ttsSpeed": "语速",
+    "ttsBaseUrl": "Base URL",
+    "ttsApiKey": "API 密钥",
+    "doubaoAppId": "App ID",
+    "doubaoAccessKey": "Access Key",
+    "asrProvider": "ASR 提供商",
+    "asrLanguage": "识别语言",
+    "asrBaseUrl": "Base URL",
+    "asrApiKey": "API 密钥",
+    "enterApiKey": "输入 API Key",
+    "enterCustomBaseUrl": "输入自定义 Base URL",
+    "browserNativeNote": "浏览器原生 ASR 无需配置，完全免费",
+    "providerOpenAITTS": "OpenAI TTS (gpt-4o-mini-tts)",
+    "providerAzureTTS": "Azure TTS",
+    "providerGLMTTS": "GLM TTS",
+    "providerQwenTTS": "Qwen TTS（阿里云百炼）",
+    "providerDoubaoTTS": "豆包 TTS 2.0（火山引擎）",
+    "providerElevenLabsTTS": "ElevenLabs TTS",
+    "providerMiniMaxTTS": "MiniMax TTS",
+    "providerBrowserNativeTTS": "浏览器原生 TTS",
+    "providerOpenAIWhisper": "OpenAI ASR (gpt-4o-mini-transcribe)",
+    "providerBrowserNative": "浏览器原生 ASR",
+    "providerQwenASR": "Qwen ASR（阿里云百炼）",
+    "providerUnpdf": "unpdf（内置）",
+    "providerMinerU": "MinerU",
+    "browserNativeTTSNote": "浏览器原生 TTS 无需配置，完全免费，使用系统内置语音",
+    "testTTS": "测试 TTS",
+    "testASR": "测试 ASR",
+    "testSuccess": "测试成功",
+    "testFailed": "测试失败",
+    "ttsTestText": "TTS 测试文本",
+    "ttsTestSuccess": "TTS 测试成功，音频已播放",
+    "ttsTestFailed": "TTS 测试失败",
+    "asrTestSuccess": "语音识别成功",
+    "asrTestFailed": "语音识别失败",
+    "asrResult": "识别结果",
+    "asrNotSupported": "浏览器不支持语音识别 API",
+    "browserTTSNotSupported": "浏览器不支持语音合成 API",
+    "browserTTSNoVoices": "当前浏览器没有可用的 TTS voice",
+    "microphoneAccessDenied": "麦克风访问被拒绝",
+    "microphoneAccessFailed": "无法访问麦克风",
+    "asrResultPlaceholder": "录音后将显示识别结果",
+    "useThisProvider": "使用此提供商",
+    "fetchVoices": "获取音色列表",
+    "fetchingVoices": "获取中...",
+    "voicesFetched": "已获取音色",
+    "fetchVoicesFailed": "获取音色失败",
+    "voiceApiKeyRequired": "需要 API 密钥",
+    "voiceBaseUrlRequired": "需要 Base URL",
+    "ttsTestTextPlaceholder": "输入要转换的文本",
+    "ttsTestTextDefault": "你好，这是一段测试语音。",
+    "startRecording": "开始录音",
+    "stopRecording": "停止录音",
+    "recording": "录音中...",
+    "transcribing": "识别中...",
+    "transcriptionResult": "识别结果",
+    "noTranscriptionResult": "无识别结果",
+    "baseUrlOptional": "Base URL（可选）",
+    "defaultValue": "默认",
+    "voiceMarin": "推荐 - 最佳质量",
+    "voiceCedar": "推荐 - 最佳质量",
+    "voiceAlloy": "中性、平衡",
+    "voiceAsh": "沉稳、专业",
+    "voiceBallad": "优雅、抒情",
+    "voiceCoral": "温暖、友好",
+    "voiceEcho": "男性、清晰",
+    "voiceFable": "叙事、生动",
+    "voiceNova": "女性、明亮",
+    "voiceOnyx": "男性、深沉",
+    "voiceSage": "智慧、沉着",
+    "voiceShimmer": "女性、柔和",
+    "voiceVerse": "自然、流畅",
+    "glmVoiceTongtong": "默认音色",
+    "glmVoiceChuichui": "锤锤音色",
+    "glmVoiceXiaochen": "小陈音色",
+    "glmVoiceJam": "动动动物圈jam音色",
+    "glmVoiceKazi": "动动动物圈kazi音色",
+    "glmVoiceDouji": "动动动物圈douji音色",
+    "glmVoiceLuodo": "动动动物圈luodo音色",
+    "qwenVoiceCherry": "阳光积极、亲切自然小姐姐",
+    "qwenVoiceSerena": "温柔小姐姐",
+    "qwenVoiceEthan": "阳光、温暖、活力、朝气",
+    "qwenVoiceChelsie": "二次元虚拟女友",
+    "qwenVoiceMomo": "撒娇搞怪，逗你开心",
+    "qwenVoiceVivian": "拽拽的、可爱的小暴躁",
+    "qwenVoiceMoon": "率性帅气",
+    "qwenVoiceMaia": "知性与温柔的碰撞",
+    "qwenVoiceKai": "耳朵的一场SPA",
+    "qwenVoiceNofish": "不会翘舌音的设计师",
+    "qwenVoiceBella": "喝酒不打醉拳的小萝莉",
+    "qwenVoiceJennifer": "品牌级、电影质感般美语女声",
+    "qwenVoiceRyan": "节奏拉满，戏感炸裂，真实与张力共舞",
+    "qwenVoiceKaterina": "御姐音色，韵律回味十足",
+    "qwenVoiceAiden": "精通厨艺的美语大男孩",
+    "qwenVoiceEldricSage": "沉稳睿智的老者，沧桑如松却心明如镜",
+    "qwenVoiceMia": "温顺如春水，乖巧如初雪",
+    "qwenVoiceMochi": "聪明伶俐的小大人，童真未泯却早慧如禅",
+    "qwenVoiceBellona": "声音洪亮，吐字清晰，人物鲜活，听得人热血沸腾",
+    "qwenVoiceVincent": "一口独特的沙哑烟嗓，一开口便道尽了千军万马与江湖豪情",
+    "qwenVoiceBunny": "\"萌属性\"爆棚的小萝莉",
+    "qwenVoiceNeil": "专业新闻主持人",
+    "qwenVoiceElias": "专业讲师音色",
+    "qwenVoiceArthur": "被岁月和旱烟浸泡过的质朴嗓音",
+    "qwenVoiceNini": "糯米糍一样又软又黏的嗓音，那一声声拉长了的\"哥哥\"",
+    "qwenVoiceEbona": "她的低语像一把生锈的钥匙，缓慢转动你内心最深处的幽暗角落",
+    "qwenVoiceSeren": "温和舒缓的声线，助你更快地进入睡眠",
+    "qwenVoicePip": "调皮捣蛋却充满童真的他来了",
+    "qwenVoiceStella": "平时是甜到发腻的迷糊少女音，但在喊出\"代表月亮消灭你\"时，瞬间充满不容置疑的爱与正义",
+    "qwenVoiceBodega": "热情的西班牙大叔",
+    "qwenVoiceSonrisa": "热情开朗的拉美大姐",
+    "qwenVoiceAlek": "一开口，是战斗民族的冷，也是毛呢大衣下的暖",
+    "qwenVoiceDolce": "慵懒的意大利大叔",
+    "qwenVoiceSohee": "温柔开朗，情绪丰富的韩国欧尼",
+    "qwenVoiceOnoAnna": "鬼灵精怪的青梅竹马",
+    "qwenVoiceLenn": "理性是底色，叛逆藏在细节里——穿西装也听后朋克的德国青年",
+    "qwenVoiceEmilien": "浪漫的法国大哥哥",
+    "qwenVoiceAndre": "声音磁性，自然舒服、沉稳男生",
+    "qwenVoiceRadioGol": "足球诗人Rádio Gol！今天我要用名字为你们解说足球",
+    "qwenVoiceJada": "风风火火的沪上阿姐",
+    "qwenVoiceDylan": "北京胡同里长大的少年",
+    "qwenVoiceLi": "耐心的瑜伽老师",
+    "qwenVoiceMarcus": "面宽话短，心实声沉——老陕的味道",
+    "qwenVoiceRoy": "诙谐直爽、市井活泼的台湾哥仔形象",
+    "qwenVoicePeter": "天津相声，专业捧哏",
+    "qwenVoiceSunny": "甜到你心里的川妹子",
+    "qwenVoiceEric": "跳脱市井的成都男子",
+    "qwenVoiceRocky": "幽默风趣的阿强",
+    "qwenVoiceKiki": "甜美的港妹闺蜜",
+    "lang_auto": "自动检测",
+    "lang_zh": "中文",
+    "lang_yue": "粤語",
+    "lang_en": "English",
+    "lang_ja": "日本語",
+    "lang_ko": "한국어",
+    "lang_es": "Español",
+    "lang_fr": "Français",
+    "lang_de": "Deutsch",
+    "lang_ru": "Русский",
+    "lang_ar": "العربية",
+    "lang_pt": "Português",
+    "lang_it": "Italiano",
+    "lang_af": "Afrikaans",
+    "lang_hy": "Հայերեն",
+    "lang_az": "Azərbaycan",
+    "lang_be": "Беларуская",
+    "lang_bs": "Bosanski",
+    "lang_bg": "Български",
+    "lang_ca": "Català",
+    "lang_hr": "Hrvatski",
+    "lang_cs": "Čeština",
+    "lang_da": "Dansk",
+    "lang_nl": "Nederlands",
+    "lang_et": "Eesti",
+    "lang_fi": "Suomi",
+    "lang_gl": "Galego",
+    "lang_el": "Ελληνικά",
+    "lang_he": "עברית",
+    "lang_hi": "हिन्दी",
+    "lang_hu": "Magyar",
+    "lang_is": "Íslenska",
+    "lang_id": "Bahasa Indonesia",
+    "lang_kn": "ಕನ್ನಡ",
+    "lang_kk": "Қазақша",
+    "lang_lv": "Latviešu",
+    "lang_lt": "Lietuvių",
+    "lang_mk": "Македонски",
+    "lang_ms": "Bahasa Melayu",
+    "lang_mr": "मराठी",
+    "lang_mi": "Te Reo Māori",
+    "lang_ne": "नेपाली",
+    "lang_no": "Norsk",
+    "lang_fa": "فارسی",
+    "lang_pl": "Polski",
+    "lang_ro": "Română",
+    "lang_sr": "Српски",
+    "lang_sk": "Slovenčina",
+    "lang_sl": "Slovenščina",
+    "lang_sw": "Kiswahili",
+    "lang_sv": "Svenska",
+    "lang_tl": "Tagalog",
+    "lang_fil": "Filipino",
+    "lang_ta": "தமிழ்",
+    "lang_th": "ไทย",
+    "lang_tr": "Türkçe",
+    "lang_uk": "Українська",
+    "lang_ur": "اردو",
+    "lang_vi": "Tiếng Việt",
+    "lang_cy": "Cymraeg",
+    "lang_zh-CN": "中文（简体，中国）",
+    "lang_zh-TW": "中文（繁體，台灣）",
+    "lang_zh-HK": "粵語（香港）",
+    "lang_yue-Hant-HK": "粵語（繁體）",
+    "lang_en-US": "English (United States)",
+    "lang_en-GB": "English (United Kingdom)",
+    "lang_en-AU": "English (Australia)",
+    "lang_en-CA": "English (Canada)",
+    "lang_en-IN": "English (India)",
+    "lang_en-NZ": "English (New Zealand)",
+    "lang_en-ZA": "English (South Africa)",
+    "lang_ja-JP": "日本語（日本）",
+    "lang_ko-KR": "한국어（대한민국）",
+    "lang_de-DE": "Deutsch (Deutschland)",
+    "lang_fr-FR": "Français (France)",
+    "lang_es-ES": "Español (España)",
+    "lang_es-MX": "Español (México)",
+    "lang_es-AR": "Español (Argentina)",
+    "lang_es-CO": "Español (Colombia)",
+    "lang_it-IT": "Italiano (Italia)",
+    "lang_pt-BR": "Português (Brasil)",
+    "lang_pt-PT": "Português (Portugal)",
+    "lang_ru-RU": "Русский (Россия)",
+    "lang_nl-NL": "Nederlands (Nederland)",
+    "lang_pl-PL": "Polski (Polska)",
+    "lang_cs-CZ": "Čeština (Česko)",
+    "lang_da-DK": "Dansk (Danmark)",
+    "lang_fi-FI": "Suomi (Suomi)",
+    "lang_sv-SE": "Svenska (Sverige)",
+    "lang_no-NO": "Norsk (Norge)",
+    "lang_tr-TR": "Türkçe (Türkiye)",
+    "lang_el-GR": "Ελληνικά (Ελλάδα)",
+    "lang_hu-HU": "Magyar (Magyarország)",
+    "lang_ro-RO": "Română (România)",
+    "lang_sk-SK": "Slovenčina (Slovensko)",
+    "lang_bg-BG": "Български (България)",
+    "lang_hr-HR": "Hrvatski (Hrvatska)",
+    "lang_ca-ES": "Català (Espanya)",
+    "lang_ar-SA": "العربية (السعودية)",
+    "lang_ar-EG": "العربية (مصر)",
+    "lang_he-IL": "עברית (ישראל)",
+    "lang_hi-IN": "हिन्दी (भारत)",
+    "lang_th-TH": "ไทย (ประเทศไทย)",
+    "lang_vi-VN": "Tiếng Việt (Việt Nam)",
+    "lang_id-ID": "Bahasa Indonesia (Indonesia)",
+    "lang_ms-MY": "Bahasa Melayu (Malaysia)",
+    "lang_fil-PH": "Filipino (Pilipinas)",
+    "lang_af-ZA": "Afrikaans (Suid-Afrika)",
+    "lang_uk-UA": "Українська (Україна)",
+    "pdfSettings": "PDF 解析",
+    "pdfParsingSettings": "PDF 解析设置",
+    "pdfDescription": "选择 PDF 解析引擎，支持文本提取、图片处理和表格识别",
+    "pdfProvider": "PDF 解析器",
+    "pdfFeatures": "支持功能",
+    "pdfApiKey": "API Key",
+    "pdfBaseUrl": "Base URL",
+    "mineruDescription": "MinerU 是一个商用 PDF 解析服务，支持高级功能如表格提取、公式识别和布局分析。",
+    "mineruApiKeyRequired": "使用前需要在 MinerU 官网申请 API Key。",
+    "mineruWarning": "注意",
+    "mineruCostWarning": "MinerU 为商用服务，使用可能产生费用。请查看 MinerU 官网了解定价详情。",
+    "enterMinerUApiKey": "输入 MinerU API Key",
+    "mineruLocalDescription": "MinerU 支持本地部署，提供高级 PDF 解析功能（表格、公式、布局分析）。需要先部署 MinerU 服务。",
+    "mineruServerAddress": "本地 MinerU 服务器地址（如：http://localhost:8080）",
+    "mineruApiKeyOptional": "仅在服务器启用认证时需要",
+    "optionalApiKey": "可选的 API Key",
+    "featureText": "文本提取",
+    "featureImages": "图片提取",
+    "featureTables": "表格提取",
+    "featureFormulas": "公式识别",
+    "featureLayoutAnalysis": "布局分析",
+    "featureMetadata": "元数据",
+    "enableImageGeneration": "启用 AI 图片生成",
+    "imageGenerationDisabledHint": "启用后，课程生成时将自动生成配图",
+    "imageSettings": "图像生成",
+    "imageSection": "文生图",
+    "imageProvider": "图像生成提供商",
+    "imageModel": "图像生成模型",
+    "providerSeedream": "Seedream（字节豆包）",
+    "providerQwenImage": "Qwen Image（阿里通义）",
+    "providerNanoBanana": "Nano Banana（Gemini）",
+    "providerMiniMaxImage": "MiniMax 图像",
+    "providerGrokImage": "Grok Image（xAI）",
+    "testImageGeneration": "测试图像生成",
+    "testImageConnectivity": "测试连接",
+    "imageConnectivitySuccess": "图像服务连接成功",
+    "imageConnectivityFailed": "图像服务连接失败",
+    "imageTestSuccess": "图像生成测试成功",
+    "imageTestFailed": "图像生成测试失败",
+    "imageTestPromptPlaceholder": "输入图像描述进行测试",
+    "imageTestPromptDefault": "一只可爱的猫咪坐在书桌上",
+    "imageGenerating": "正在生成图像...",
+    "imageGenerationFailed": "图像生成失败",
+    "enableVideoGeneration": "启用 AI 视频生成",
+    "videoGenerationDisabledHint": "启用后，课程生成时将自动生成视频",
+    "videoSettings": "视频生成",
+    "videoSection": "文生视频",
+    "videoProvider": "视频生成提供商",
+    "videoModel": "视频生成模型",
+    "providerSeedance": "Seedance（字节跳动）",
+    "providerKling": "可灵（快手）",
+    "providerVeo": "Veo（Google）",
+    "providerSora": "Sora（OpenAI）",
+    "providerMiniMaxVideo": "MiniMax 视频",
+    "providerGrokVideo": "Grok Video（xAI）",
+    "testVideoGeneration": "测试视频生成",
+    "testVideoConnectivity": "测试连接",
+    "videoConnectivitySuccess": "视频服务连接成功",
+    "videoConnectivityFailed": "视频服务连接失败",
+    "testingConnection": "正在测试...",
+    "videoTestSuccess": "视频生成测试成功",
+    "videoTestFailed": "视频生成测试失败",
+    "videoTestPromptDefault": "一只可爱的猫咪在书桌上行走",
+    "videoGenerating": "正在生成视频（预计1-2分钟）...",
+    "videoGenerationWarning": "视频生成通常需要1-2分钟，请耐心等待",
+    "mediaRetry": "重试",
+    "mediaContentSensitive": "抱歉，该内容触发了安全检查",
+    "mediaGenerationDisabled": "已在设置中关闭生成",
+    "singleAgent": "单智能体模式",
+    "multiAgent": "多智能体模式",
+    "selectAgents": "选择智能体",
+    "noVisionWarning": "当前模型不支持视觉能力，图片仍可放入幻灯片，但模型无法理解图片内容来优化选择和布局",
+    "serverConfigured": "服务端",
+    "serverConfiguredNotice": "管理员已在服务端配置了此提供方的 API Key，可直接使用。也可输入自己的 Key 覆盖。",
+    "optionalOverride": "可选，留空则使用服务端配置",
+    "setupNeeded": "请先完成配置",
+    "modelNotConfigured": "请选择一个模型以开始使用",
+    "dangerZone": "危险区域",
+    "clearCache": "清空本地缓存",
+    "clearCacheDescription": "删除所有本地存储的数据，包括课堂记录、对话历史、音频缓存和应用配置。此操作不可撤销。",
+    "clearCacheConfirmTitle": "确定要清空所有缓存吗？",
+    "clearCacheConfirmDescription": "此操作将永久删除以下所有数据，且无法恢复：",
+    "clearCacheConfirmItems": "课堂和场景数据、对话历史记录、音频和图片缓存、应用设置和偏好",
+    "clearCacheConfirmInput": "请输入「确认删除」以继续",
+    "clearCacheConfirmPhrase": "确认删除",
+    "clearCacheButton": "永久删除所有数据",
+    "clearCacheSuccess": "缓存已清空，页面即将刷新",
+    "clearCacheFailed": "清空缓存失败，请重试",
+    "webSearchSettings": "网络搜索",
+    "webSearchApiKey": "Tavily API Key",
+    "webSearchApiKeyPlaceholder": "输入你的 Tavily API Key",
+    "webSearchApiKeyPlaceholderServer": "已配置服务端密钥，可选填覆盖",
+    "webSearchApiKeyHint": "从 tavily.com 获取 API Key，用于网络搜索",
+    "webSearchBaseUrl": "Base URL",
+    "webSearchServerConfigured": "服务端已配置 Tavily API Key",
+    "optional": "可选"
+  },
+  "profile": {
+    "title": "个人资料",
+    "defaultNickname": "同学",
+    "chooseAvatar": "选择头像",
+    "uploadAvatar": "上传",
+    "bioPlaceholder": "介绍一下自己，AI老师会根据你的背景个性化教学...",
+    "avatarHint": "你的头像将显示在课堂讨论和对话中",
+    "fileTooLarge": "图片过大，请选择小于 5MB 的图片",
+    "invalidFileType": "请选择图片文件",
+    "editTooltip": "点击编辑个人资料"
+  },
+  "media": {
+    "imageCapability": "图像生成",
+    "imageHint": "课件中生成配图",
+    "videoCapability": "视频生成",
+    "videoHint": "课件中生成视频",
+    "ttsCapability": "语音合成",
+    "ttsHint": "AI 老师语音讲解",
+    "asrCapability": "语音识别",
+    "asrHint": "语音输入参与讨论",
+    "provider": "服务商",
+    "model": "模型",
+    "voice": "音色",
+    "speed": "语速",
+    "language": "语言"
+  }
+}
diff --git a/lib/i18n/settings.ts b/lib/i18n/settings.ts
deleted file mode 100644
index 356fea554..000000000
--- a/lib/i18n/settings.ts
+++ /dev/null
@@ -1,1196 +0,0 @@
-export const settingsZhCN = {
-  settings: {
-    title: '设置',
-    description: '配置应用程序设置',
-    language: '语言',
-    languageDesc: '选择界面语言',
-    theme: '主题',
-    themeDesc: '选择主题模式（浅色/深色/跟随系统）',
-    themeOptions: {
-      light: '浅色',
-      dark: '深色',
-      system: '跟随系统',
-    },
-    apiKey: 'API密钥',
-    apiKeyDesc: '配置你的API密钥',
-    apiBaseUrl: 'API端点地址',
-    apiBaseUrlDesc: '配置你的API端点地址',
-    apiKeyRequired: 'API密钥不能为空',
-    model: '模型配置',
-    modelDesc: '配置AI模型',
-    modelPlaceholder: '输入或选择模型名称',
-    ttsModel: 'TTS模型',
-    ttsModelDesc: '配置TTS模型',
-    ttsModelPlaceholder: '输入或选择TTS模型名称',
-    ttsModelOptions: {
-      openaiTts: 'OpenAI TTS',
-      azureTts: 'Azure TTS',
-    },
-    availableModels: '可用模型',
-    modelSelectedViaVoice: '模型随音色选择自动确定',
-    testConnection: '测试连接',
-    testConnectionDesc: '测试当前API配置是否可用',
-    testing: '测试中...',
-    agentSettings: '智能体设置',
-    agentSettingsDesc: '选择参与对话的智能体。选择1个为单智能体模式，选择多个为多智能体协作模式。',
-    agentMode: '智能体模式',
-    agentModePreset: '预设模式',
-    agentModeAuto: '自动生成',
-    agentModeAutoDesc: 'AI 将根据课程内容自动生成适合的课堂角色',
-    autoAgentCount: '生成数量',
-    autoAgentCountDesc: '自动生成的角色数量（包含教师）',
-    atLeastOneAgent: '请至少选择1个智能体',
-    singleAgentMode: '单智能体模式',
-    directAnswer: '直接回答',
-    multiAgentMode: '多智能体模式',
-    agentsCollaborating: '协作讨论',
-    agentsCollaboratingCount: '已选择 {count} 个智能体协作讨论',
-    maxTurns: '最大讨论轮数',
-    maxTurnsDesc: '智能体之间最多讨论多少轮（每个智能体完成动作并回复算一轮）',
-    priority: '优先级',
-    actions: '动作',
-    actionCount: '{count} 个动作',
-    selectedAgent: '选中的智能体',
-    selectedAgents: '选中的智能体',
-    required: '必选',
-    agentNames: {
-      'default-1': 'AI教师',
-      'default-2': 'AI助教',
-      'default-3': '显眼包',
-      'default-4': '好奇宝宝',
-      'default-5': '笔记员',
-      'default-6': '思考者',
-    },
-    agentRoles: {
-      teacher: '教师',
-      assistant: '助教',
-      student: '学生',
-    },
-    agentDescriptions: {
-      'default-1': '主讲教师，清晰有条理地讲解知识',
-      'default-2': '辅助讲解，帮助同学理解重点',
-      'default-3': '活跃气氛，用幽默让课堂更有趣',
-      'default-4': '充满好奇心，总爱追问为什么',
-      'default-5': '认真记录，整理课堂重点笔记',
-      'default-6': '深入思考，喜欢探讨问题本质',
-    },
-    close: '关闭',
-    save: '保存',
-    // Provider settings
-    providers: '语言模型',
-    addProviderDescription: '添加自定义模型提供方以扩展可用的AI模型',
-    providerNames: {
-      openai: 'OpenAI',
-      anthropic: 'Claude',
-      google: 'Gemini',
-      deepseek: 'DeepSeek',
-      qwen: '通义千问',
-      kimi: 'Kimi',
-      minimax: 'MiniMax',
-      glm: 'GLM',
-      siliconflow: '硅基流动',
-    },
-    providerTypes: {
-      openai: 'OpenAI 协议',
-      anthropic: 'Claude 协议',
-      google: 'Gemini 协议',
-    },
-    modelCount: '个模型',
-    modelSingular: '个模型',
-    defaultModel: '默认模型',
-    webSearch: '联网搜索',
-    mcp: 'MCP',
-    knowledgeBase: '知识库',
-    documentParser: '文档解析器',
-    conversationSettings: '对话设置',
-    keyboardShortcuts: '键盘快捷键',
-    generalSettings: '常规设置',
-    systemSettings: '系统设置',
-    addProvider: '添加',
-    importFromClipboard: '从剪贴板导入',
-    apiSecret: 'API 密钥',
-    apiHost: 'Base URL',
-    requestUrl: '请求地址',
-    models: '模型',
-    addModel: '新建',
-    reset: '重置',
-    fetch: '获取',
-    connectionSuccess: '连接成功',
-    connectionFailed: '连接失败',
-    // Model capabilities
-    capabilities: {
-      vision: '视觉',
-      tools: '工具',
-      streaming: '流式',
-    },
-    contextWindow: '上下文',
-    contextShort: '上下文',
-    outputWindow: '输出',
-    // Provider management
-    addProviderButton: '添加',
-    addProviderDialog: '添加模型提供方',
-    providerName: '名称',
-    providerNamePlaceholder: '例如：我的OpenAI代理',
-    providerNameRequired: '请输入提供方名称',
-    providerApiMode: 'API 模式',
-    apiModeOpenAI: 'OpenAI 协议',
-    apiModeAnthropic: 'Claude 协议',
-    apiModeGoogle: 'Gemini 协议',
-    defaultBaseUrl: '默认 Base URL',
-    providerIcon: 'Provider 图标 URL',
-    requiresApiKey: '需要 API 密钥',
-    deleteProvider: '删除提供方',
-    deleteProviderConfirm: '确定要删除此提供方吗？',
-    cannotDeleteBuiltIn: '无法删除内置提供方',
-    resetToDefault: '重置为默认配置',
-    resetToDefaultDescription: '将模型列表恢复到默认状态（保留 API 密钥和 Base URL）',
-    resetConfirmDescription:
-      '此操作将清除所有自定义模型，恢复到内置的默认模型列表。API 密钥和 Base URL 将被保留。',
-    confirmReset: '确认重置',
-    resetSuccess: '已成功重置为默认配置',
-    saveSuccess: '配置已保存',
-    saveFailed: '保存失败，请重试',
-    cannotDeleteBuiltInModel: '无法删除内置模型',
-    cannotEditBuiltInModel: '无法编辑内置模型',
-    modelIdRequired: '请输入模型 ID',
-    noModelsAvailable: '没有可用于测试的模型',
-    providerMetadata: 'Provider 元数据',
-    // Model editing
-    editModel: '编辑模型',
-    editModelDescription: '编辑模型配置和能力',
-    addNewModel: '新建模型',
-    addNewModelDescription: '添加新的模型配置',
-    modelId: '模型ID',
-    modelIdPlaceholder: '例如：gpt-4o',
-    modelName: '显示名称',
-    modelNamePlaceholder: '可选',
-    modelCapabilities: '能力',
-    advancedSettings: '高级设置',
-    contextWindowLabel: '上下文窗口',
-    contextWindowPlaceholder: '例如 128000',
-    outputWindowLabel: '最大输出Token数',
-    outputWindowPlaceholder: '例如 4096',
-    testModel: '测试模型',
-    deleteModel: '删除',
-    cancelEdit: '取消',
-    saveModel: '保存',
-    modelsManagementDescription:
-      '在此管理该提供方的模型列表。若需选择使用的模型，请前往"常规设置"。',
-    // General settings
-    howToUse: '使用说明',
-    step1ConfigureProvider:
-      '前往"模型提供方"页面，选择或添加一个提供方，配置连接信息（API 密钥、Base URL 等）',
-    step2SelectModel: '在下方"使用模型"中选择要使用的模型',
-    step3StartUsing: '保存设置后，系统将使用您选择的模型',
-    activeModel: '使用模型',
-    activeModelDescription: '选择当前用于 AI 对话和内容生成的模型',
-    selectModel: '选择模型',
-    searchModels: '搜索模型',
-    noModelsFound: '未找到匹配的模型',
-    noConfiguredProviders: '暂无已配置的提供方',
-    configureProvidersFirst: '请先在左侧"模型提供方"中配置提供方连接信息',
-    currentlyUsing: '当前使用',
-    // TTS settings
-    ttsSettings: '语音合成',
-    // ASR settings
-    asrSettings: '语音识别',
-    // Audio settings (legacy)
-    audioSettings: '音频设置',
-    ttsSection: '文字转语音 (TTS)',
-    asrSection: '语音识别 (ASR)',
-    ttsDescription: 'TTS (Text-to-Speech) - 将文字转换为语音',
-    asrDescription: 'ASR (Automatic Speech Recognition) - 将语音转换为文字',
-    enableTTS: '启用语音合成',
-    ttsEnabledDescription: '开启后，课程生成时将自动合成语音',
-    ttsVoiceConfigHint: '每个 Agent 的音色可在首页「课堂角色配置」中设置',
-    enableASR: '启用语音识别',
-    asrEnabledDescription: '开启后，学生可使用麦克风进行语音输入',
-    ttsProvider: 'TTS 提供商',
-    ttsLanguageFilter: '语言筛选',
-    allLanguages: '全部语言',
-    ttsVoice: '音色',
-    ttsSpeed: '语速',
-    ttsBaseUrl: 'Base URL',
-    ttsApiKey: 'API 密钥',
-    doubaoAppId: 'App ID',
-    doubaoAccessKey: 'Access Key',
-    asrProvider: 'ASR 提供商',
-    asrLanguage: '识别语言',
-    asrBaseUrl: 'Base URL',
-    asrApiKey: 'API 密钥',
-    enterApiKey: '输入 API Key',
-    enterCustomBaseUrl: '输入自定义 Base URL',
-    browserNativeNote: '浏览器原生 ASR 无需配置，完全免费',
-    // Audio provider names
-    providerOpenAITTS: 'OpenAI TTS (gpt-4o-mini-tts)',
-    providerAzureTTS: 'Azure TTS',
-    providerGLMTTS: 'GLM TTS',
-    providerQwenTTS: 'Qwen TTS（阿里云百炼）',
-    providerDoubaoTTS: '豆包 TTS 2.0（火山引擎）',
-    providerElevenLabsTTS: 'ElevenLabs TTS',
-    providerMiniMaxTTS: 'MiniMax TTS',
-    providerBrowserNativeTTS: '浏览器原生 TTS',
-    providerOpenAIWhisper: 'OpenAI ASR (gpt-4o-mini-transcribe)',
-    providerBrowserNative: '浏览器原生 ASR',
-    providerQwenASR: 'Qwen ASR（阿里云百炼）',
-    providerUnpdf: 'unpdf（内置）',
-    providerMinerU: 'MinerU',
-    browserNativeTTSNote: '浏览器原生 TTS 无需配置，完全免费，使用系统内置语音',
-    testTTS: '测试 TTS',
-    testASR: '测试 ASR',
-    testSuccess: '测试成功',
-    testFailed: '测试失败',
-    ttsTestText: 'TTS 测试文本',
-    ttsTestSuccess: 'TTS 测试成功，音频已播放',
-    ttsTestFailed: 'TTS 测试失败',
-    asrTestSuccess: '语音识别成功',
-    asrTestFailed: '语音识别失败',
-    asrResult: '识别结果',
-    asrNotSupported: '浏览器不支持语音识别 API',
-    browserTTSNotSupported: '浏览器不支持语音合成 API',
-    browserTTSNoVoices: '当前浏览器没有可用的 TTS voice',
-    microphoneAccessDenied: '麦克风访问被拒绝',
-    microphoneAccessFailed: '无法访问麦克风',
-    asrResultPlaceholder: '录音后将显示识别结果',
-    useThisProvider: '使用此提供商',
-    fetchVoices: '获取音色列表',
-    fetchingVoices: '获取中...',
-    voicesFetched: '已获取音色',
-    fetchVoicesFailed: '获取音色失败',
-    voiceApiKeyRequired: '需要 API 密钥',
-    voiceBaseUrlRequired: '需要 Base URL',
-    ttsTestTextPlaceholder: '输入要转换的文本',
-    ttsTestTextDefault: '你好，这是一段测试语音。',
-    startRecording: '开始录音',
-    stopRecording: '停止录音',
-    recording: '录音中...',
-    transcribing: '识别中...',
-    transcriptionResult: '识别结果',
-    noTranscriptionResult: '无识别结果',
-    baseUrlOptional: 'Base URL（可选）',
-    defaultValue: '默认',
-    // TTS Voice descriptions (OpenAI)
-    voiceMarin: '推荐 - 最佳质量',
-    voiceCedar: '推荐 - 最佳质量',
-    voiceAlloy: '中性、平衡',
-    voiceAsh: '沉稳、专业',
-    voiceBallad: '优雅、抒情',
-    voiceCoral: '温暖、友好',
-    voiceEcho: '男性、清晰',
-    voiceFable: '叙事、生动',
-    voiceNova: '女性、明亮',
-    voiceOnyx: '男性、深沉',
-    voiceSage: '智慧、沉着',
-    voiceShimmer: '女性、柔和',
-    voiceVerse: '自然、流畅',
-    // TTS Voice descriptions (GLM)
-    glmVoiceTongtong: '默认音色',
-    glmVoiceChuichui: '锤锤音色',
-    glmVoiceXiaochen: '小陈音色',
-    glmVoiceJam: '动动动物圈jam音色',
-    glmVoiceKazi: '动动动物圈kazi音色',
-    glmVoiceDouji: '动动动物圈douji音色',
-    glmVoiceLuodo: '动动动物圈luodo音色',
-    // TTS Voice descriptions (Qwen)
-    qwenVoiceCherry: '阳光积极、亲切自然小姐姐',
-    qwenVoiceSerena: '温柔小姐姐',
-    qwenVoiceEthan: '阳光、温暖、活力、朝气',
-    qwenVoiceChelsie: '二次元虚拟女友',
-    qwenVoiceMomo: '撒娇搞怪，逗你开心',
-    qwenVoiceVivian: '拽拽的、可爱的小暴躁',
-    qwenVoiceMoon: '率性帅气',
-    qwenVoiceMaia: '知性与温柔的碰撞',
-    qwenVoiceKai: '耳朵的一场SPA',
-    qwenVoiceNofish: '不会翘舌音的设计师',
-    qwenVoiceBella: '喝酒不打醉拳的小萝莉',
-    qwenVoiceJennifer: '品牌级、电影质感般美语女声',
-    qwenVoiceRyan: '节奏拉满，戏感炸裂，真实与张力共舞',
-    qwenVoiceKaterina: '御姐音色，韵律回味十足',
-    qwenVoiceAiden: '精通厨艺的美语大男孩',
-    qwenVoiceEldricSage: '沉稳睿智的老者，沧桑如松却心明如镜',
-    qwenVoiceMia: '温顺如春水，乖巧如初雪',
-    qwenVoiceMochi: '聪明伶俐的小大人，童真未泯却早慧如禅',
-    qwenVoiceBellona: '声音洪亮，吐字清晰，人物鲜活，听得人热血沸腾',
-    qwenVoiceVincent: '一口独特的沙哑烟嗓，一开口便道尽了千军万马与江湖豪情',
-    qwenVoiceBunny: '"萌属性"爆棚的小萝莉',
-    qwenVoiceNeil: '专业新闻主持人',
-    qwenVoiceElias: '专业讲师音色',
-    qwenVoiceArthur: '被岁月和旱烟浸泡过的质朴嗓音',
-    qwenVoiceNini: '糯米糍一样又软又黏的嗓音，那一声声拉长了的"哥哥"',
-    qwenVoiceEbona: '她的低语像一把生锈的钥匙，缓慢转动你内心最深处的幽暗角落',
-    qwenVoiceSeren: '温和舒缓的声线，助你更快地进入睡眠',
-    qwenVoicePip: '调皮捣蛋却充满童真的他来了',
-    qwenVoiceStella:
-      '平时是甜到发腻的迷糊少女音，但在喊出"代表月亮消灭你"时，瞬间充满不容置疑的爱与正义',
-    qwenVoiceBodega: '热情的西班牙大叔',
-    qwenVoiceSonrisa: '热情开朗的拉美大姐',
-    qwenVoiceAlek: '一开口，是战斗民族的冷，也是毛呢大衣下的暖',
-    qwenVoiceDolce: '慵懒的意大利大叔',
-    qwenVoiceSohee: '温柔开朗，情绪丰富的韩国欧尼',
-    qwenVoiceOnoAnna: '鬼灵精怪的青梅竹马',
-    qwenVoiceLenn: '理性是底色，叛逆藏在细节里——穿西装也听后朋克的德国青年',
-    qwenVoiceEmilien: '浪漫的法国大哥哥',
-    qwenVoiceAndre: '声音磁性，自然舒服、沉稳男生',
-    qwenVoiceRadioGol: '足球诗人Rádio Gol！今天我要用名字为你们解说足球',
-    qwenVoiceJada: '风风火火的沪上阿姐',
-    qwenVoiceDylan: '北京胡同里长大的少年',
-    qwenVoiceLi: '耐心的瑜伽老师',
-    qwenVoiceMarcus: '面宽话短，心实声沉——老陕的味道',
-    qwenVoiceRoy: '诙谐直爽、市井活泼的台湾哥仔形象',
-    qwenVoicePeter: '天津相声，专业捧哏',
-    qwenVoiceSunny: '甜到你心里的川妹子',
-    qwenVoiceEric: '跳脱市井的成都男子',
-    qwenVoiceRocky: '幽默风趣的阿强',
-    qwenVoiceKiki: '甜美的港妹闺蜜',
-    // ASR Language names (native forms - autoglossonyms)
-    lang_auto: '自动检测',
-    lang_zh: '中文',
-    lang_yue: '粤語',
-    lang_en: 'English',
-    lang_ja: '日本語',
-    lang_ko: '한국어',
-    lang_es: 'Español',
-    lang_fr: 'Français',
-    lang_de: 'Deutsch',
-    lang_ru: 'Русский',
-    lang_ar: 'العربية',
-    lang_pt: 'Português',
-    lang_it: 'Italiano',
-    lang_af: 'Afrikaans',
-    lang_hy: 'Հայերեն',
-    lang_az: 'Azərbaycan',
-    lang_be: 'Беларуская',
-    lang_bs: 'Bosanski',
-    lang_bg: 'Български',
-    lang_ca: 'Català',
-    lang_hr: 'Hrvatski',
-    lang_cs: 'Čeština',
-    lang_da: 'Dansk',
-    lang_nl: 'Nederlands',
-    lang_et: 'Eesti',
-    lang_fi: 'Suomi',
-    lang_gl: 'Galego',
-    lang_el: 'Ελληνικά',
-    lang_he: 'עברית',
-    lang_hi: 'हिन्दी',
-    lang_hu: 'Magyar',
-    lang_is: 'Íslenska',
-    lang_id: 'Bahasa Indonesia',
-    lang_kn: 'ಕನ್ನಡ',
-    lang_kk: 'Қазақша',
-    lang_lv: 'Latviešu',
-    lang_lt: 'Lietuvių',
-    lang_mk: 'Македонски',
-    lang_ms: 'Bahasa Melayu',
-    lang_mr: 'मराठी',
-    lang_mi: 'Te Reo Māori',
-    lang_ne: 'नेपाली',
-    lang_no: 'Norsk',
-    lang_fa: 'فارسی',
-    lang_pl: 'Polski',
-    lang_ro: 'Română',
-    lang_sr: 'Српски',
-    lang_sk: 'Slovenčina',
-    lang_sl: 'Slovenščina',
-    lang_sw: 'Kiswahili',
-    lang_sv: 'Svenska',
-    lang_tl: 'Tagalog',
-    lang_fil: 'Filipino',
-    lang_ta: 'தமிழ்',
-    lang_th: 'ไทย',
-    lang_tr: 'Türkçe',
-    lang_uk: 'Українська',
-    lang_ur: 'اردو',
-    lang_vi: 'Tiếng Việt',
-    lang_cy: 'Cymraeg',
-    // BCP-47 format language codes (for Web Speech API)
-    'lang_zh-CN': '中文（简体，中国）',
-    'lang_zh-TW': '中文（繁體，台灣）',
-    'lang_zh-HK': '粵語（香港）',
-    'lang_yue-Hant-HK': '粵語（繁體）',
-    'lang_en-US': 'English (United States)',
-    'lang_en-GB': 'English (United Kingdom)',
-    'lang_en-AU': 'English (Australia)',
-    'lang_en-CA': 'English (Canada)',
-    'lang_en-IN': 'English (India)',
-    'lang_en-NZ': 'English (New Zealand)',
-    'lang_en-ZA': 'English (South Africa)',
-    'lang_ja-JP': '日本語（日本）',
-    'lang_ko-KR': '한국어（대한민국）',
-    'lang_de-DE': 'Deutsch (Deutschland)',
-    'lang_fr-FR': 'Français (France)',
-    'lang_es-ES': 'Español (España)',
-    'lang_es-MX': 'Español (México)',
-    'lang_es-AR': 'Español (Argentina)',
-    'lang_es-CO': 'Español (Colombia)',
-    'lang_it-IT': 'Italiano (Italia)',
-    'lang_pt-BR': 'Português (Brasil)',
-    'lang_pt-PT': 'Português (Portugal)',
-    'lang_ru-RU': 'Русский (Россия)',
-    'lang_nl-NL': 'Nederlands (Nederland)',
-    'lang_pl-PL': 'Polski (Polska)',
-    'lang_cs-CZ': 'Čeština (Česko)',
-    'lang_da-DK': 'Dansk (Danmark)',
-    'lang_fi-FI': 'Suomi (Suomi)',
-    'lang_sv-SE': 'Svenska (Sverige)',
-    'lang_no-NO': 'Norsk (Norge)',
-    'lang_tr-TR': 'Türkçe (Türkiye)',
-    'lang_el-GR': 'Ελληνικά (Ελλάδα)',
-    'lang_hu-HU': 'Magyar (Magyarország)',
-    'lang_ro-RO': 'Română (România)',
-    'lang_sk-SK': 'Slovenčina (Slovensko)',
-    'lang_bg-BG': 'Български (България)',
-    'lang_hr-HR': 'Hrvatski (Hrvatska)',
-    'lang_ca-ES': 'Català (Espanya)',
-    'lang_ar-SA': 'العربية (السعودية)',
-    'lang_ar-EG': 'العربية (مصر)',
-    'lang_he-IL': 'עברית (ישראל)',
-    'lang_hi-IN': 'हिन्दी (भारत)',
-    'lang_th-TH': 'ไทย (ประเทศไทย)',
-    'lang_vi-VN': 'Tiếng Việt (Việt Nam)',
-    'lang_id-ID': 'Bahasa Indonesia (Indonesia)',
-    'lang_ms-MY': 'Bahasa Melayu (Malaysia)',
-    'lang_fil-PH': 'Filipino (Pilipinas)',
-    'lang_af-ZA': 'Afrikaans (Suid-Afrika)',
-    'lang_uk-UA': 'Українська (Україна)',
-    // PDF settings
-    pdfSettings: 'PDF 解析',
-    pdfParsingSettings: 'PDF 解析设置',
-    pdfDescription: '选择 PDF 解析引擎，支持文本提取、图片处理和表格识别',
-    pdfProvider: 'PDF 解析器',
-    pdfFeatures: '支持功能',
-    pdfApiKey: 'API Key',
-    pdfBaseUrl: 'Base URL',
-    mineruDescription:
-      'MinerU 是一个商用 PDF 解析服务，支持高级功能如表格提取、公式识别和布局分析。',
-    mineruApiKeyRequired: '使用前需要在 MinerU 官网申请 API Key。',
-    mineruWarning: '注意',
-    mineruCostWarning: 'MinerU 为商用服务，使用可能产生费用。请查看 MinerU 官网了解定价详情。',
-    enterMinerUApiKey: '输入 MinerU API Key',
-    mineruLocalDescription:
-      'MinerU 支持本地部署，提供高级 PDF 解析功能（表格、公式、布局分析）。需要先部署 MinerU 服务。',
-    mineruServerAddress: '本地 MinerU 服务器地址（如：http://localhost:8080）',
-    mineruApiKeyOptional: '仅在服务器启用认证时需要',
-    optionalApiKey: '可选的 API Key',
-    featureText: '文本提取',
-    featureImages: '图片提取',
-    featureTables: '表格提取',
-    featureFormulas: '公式识别',
-    featureLayoutAnalysis: '布局分析',
-    featureMetadata: '元数据',
-    // Image Generation settings
-    enableImageGeneration: '启用 AI 图片生成',
-    imageGenerationDisabledHint: '启用后，课程生成时将自动生成配图',
-    imageSettings: '图像生成',
-    imageSection: '文生图',
-    imageProvider: '图像生成提供商',
-    imageModel: '图像生成模型',
-    providerSeedream: 'Seedream（字节豆包）',
-    providerQwenImage: 'Qwen Image（阿里通义）',
-    providerNanoBanana: 'Nano Banana（Gemini）',
-    providerMiniMaxImage: 'MiniMax 图像',
-    providerGrokImage: 'Grok Image（xAI）',
-    testImageGeneration: '测试图像生成',
-    testImageConnectivity: '测试连接',
-    imageConnectivitySuccess: '图像服务连接成功',
-    imageConnectivityFailed: '图像服务连接失败',
-    imageTestSuccess: '图像生成测试成功',
-    imageTestFailed: '图像生成测试失败',
-    imageTestPromptPlaceholder: '输入图像描述进行测试',
-    imageTestPromptDefault: '一只可爱的猫咪坐在书桌上',
-    imageGenerating: '正在生成图像...',
-    imageGenerationFailed: '图像生成失败',
-    // Video Generation settings
-    enableVideoGeneration: '启用 AI 视频生成',
-    videoGenerationDisabledHint: '启用后，课程生成时将自动生成视频',
-    videoSettings: '视频生成',
-    videoSection: '文生视频',
-    videoProvider: '视频生成提供商',
-    videoModel: '视频生成模型',
-    providerSeedance: 'Seedance（字节跳动）',
-    providerKling: '可灵（快手）',
-    providerVeo: 'Veo（Google）',
-    providerSora: 'Sora（OpenAI）',
-    providerMiniMaxVideo: 'MiniMax 视频',
-    providerGrokVideo: 'Grok Video（xAI）',
-    testVideoGeneration: '测试视频生成',
-    testVideoConnectivity: '测试连接',
-    videoConnectivitySuccess: '视频服务连接成功',
-    videoConnectivityFailed: '视频服务连接失败',
-    testingConnection: '正在测试...',
-    videoTestSuccess: '视频生成测试成功',
-    videoTestFailed: '视频生成测试失败',
-    videoTestPromptDefault: '一只可爱的猫咪在书桌上行走',
-    videoGenerating: '正在生成视频（预计1-2分钟）...',
-    videoGenerationWarning: '视频生成通常需要1-2分钟，请耐心等待',
-    mediaRetry: '重试',
-    mediaContentSensitive: '抱歉，该内容触发了安全检查',
-    mediaGenerationDisabled: '已在设置中关闭生成',
-    // Agent settings (kept with main settings block above)
-    singleAgent: '单智能体模式',
-    multiAgent: '多智能体模式',
-    selectAgents: '选择智能体',
-    noVisionWarning:
-      '当前模型不支持视觉能力，图片仍可放入幻灯片，但模型无法理解图片内容来优化选择和布局',
-    // Server provider configuration
-    serverConfigured: '服务端',
-    serverConfiguredNotice:
-      '管理员已在服务端配置了此提供方的 API Key，可直接使用。也可输入自己的 Key 覆盖。',
-    optionalOverride: '可选，留空则使用服务端配置',
-    // Access code
-    setupNeeded: '请先完成配置',
-    modelNotConfigured: '请选择一个模型以开始使用',
-    // Clear cache
-    dangerZone: '危险区域',
-    clearCache: '清空本地缓存',
-    clearCacheDescription:
-      '删除所有本地存储的数据，包括课堂记录、对话历史、音频缓存和应用配置。此操作不可撤销。',
-    clearCacheConfirmTitle: '确定要清空所有缓存吗？',
-    clearCacheConfirmDescription: '此操作将永久删除以下所有数据，且无法恢复：',
-    clearCacheConfirmItems: '课堂和场景数据、对话历史记录、音频和图片缓存、应用设置和偏好',
-    clearCacheConfirmInput: '请输入「确认删除」以继续',
-    clearCacheConfirmPhrase: '确认删除',
-    clearCacheButton: '永久删除所有数据',
-    clearCacheSuccess: '缓存已清空，页面即将刷新',
-    clearCacheFailed: '清空缓存失败，请重试',
-    // Web Search settings
-    webSearchSettings: '网络搜索',
-    webSearchApiKey: 'Tavily API Key',
-    webSearchApiKeyPlaceholder: '输入你的 Tavily API Key',
-    webSearchApiKeyPlaceholderServer: '已配置服务端密钥，可选填覆盖',
-    webSearchApiKeyHint: '从 tavily.com 获取 API Key，用于网络搜索',
-    webSearchBaseUrl: 'Base URL',
-    webSearchServerConfigured: '服务端已配置 Tavily API Key',
-    optional: '可选',
-  },
-  profile: {
-    title: '个人资料',
-    defaultNickname: '同学',
-    chooseAvatar: '选择头像',
-    uploadAvatar: '上传',
-    bioPlaceholder: '介绍一下自己，AI老师会根据你的背景个性化教学...',
-    avatarHint: '你的头像将显示在课堂讨论和对话中',
-    fileTooLarge: '图片过大，请选择小于 5MB 的图片',
-    invalidFileType: '请选择图片文件',
-    editTooltip: '点击编辑个人资料',
-  },
-  media: {
-    imageCapability: '图像生成',
-    imageHint: '课件中生成配图',
-    videoCapability: '视频生成',
-    videoHint: '课件中生成视频',
-    ttsCapability: '语音合成',
-    ttsHint: 'AI 老师语音讲解',
-    asrCapability: '语音识别',
-    asrHint: '语音输入参与讨论',
-    provider: '服务商',
-    model: '模型',
-    voice: '音色',
-    speed: '语速',
-    language: '语言',
-  },
-} as const;
-
-export const settingsEnUS = {
-  settings: {
-    title: 'Settings',
-    description: 'Configure application settings',
-    language: 'Language',
-    languageDesc: 'Select interface language',
-    theme: 'Theme',
-    themeDesc: 'Select theme mode (Light/Dark/System)',
-    themeOptions: {
-      light: 'Light',
-      dark: 'Dark',
-      system: 'System',
-    },
-    apiKey: 'API Key',
-    apiKeyDesc: 'Configure your API key',
-    apiBaseUrl: 'API Endpoint URL',
-    apiBaseUrlDesc: 'Configure your API endpoint URL',
-    apiKeyRequired: 'API key cannot be empty',
-    model: 'Model Configuration',
-    modelDesc: 'Configure AI models',
-    modelPlaceholder: 'Enter or select model name',
-    ttsModel: 'TTS Model',
-    ttsModelDesc: 'Configure TTS models',
-    ttsModelPlaceholder: 'Enter or select TTS model name',
-    ttsModelOptions: {
-      openaiTts: 'OpenAI TTS',
-      azureTts: 'Azure TTS',
-    },
-    availableModels: 'Available Models',
-    modelSelectedViaVoice: 'Model is determined by voice selection',
-    testConnection: 'Test Connection',
-    testConnectionDesc: 'Test current API configuration is available',
-    testing: 'Testing...',
-    agentSettings: 'Agent Settings',
-    agentSettingsDesc:
-      'Select the agents to participate in the conversation. Select 1 for single agent mode, select multiple for multi-agent collaborative mode.',
-    agentMode: 'Agent Mode',
-    agentModePreset: 'Preset',
-    agentModeAuto: 'Auto-generate',
-    agentModeAutoDesc: 'AI will automatically generate appropriate roles',
-    autoAgentCount: 'Agent Count',
-    autoAgentCountDesc: 'Number of agents to auto-generate (including teacher)',
-    atLeastOneAgent: 'Please select at least 1 agent',
-    singleAgentMode: 'Single Agent Mode',
-    directAnswer: 'Direct Answer',
-    multiAgentMode: 'Multi-Agent Mode',
-    agentsCollaborating: 'Collaborative Discussion',
-    agentsCollaboratingCount: '{count} agents selected for collaborative discussion',
-    maxTurns: 'Max Discussion Turns',
-    maxTurnsDesc:
-      'The maximum number of discussion turns between agents (each agent completes actions and reply counts as one turn)',
-    priority: 'Priority',
-    actions: 'Actions',
-    actionCount: '{count} actions',
-    selectedAgent: 'Selected Agent',
-    selectedAgents: 'Selected Agents',
-    required: 'Required',
-    agentNames: {
-      'default-1': 'AI Teacher',
-      'default-2': 'AI Assistant',
-      'default-3': 'Class Clown',
-      'default-4': 'Curious Mind',
-      'default-5': 'Note Taker',
-      'default-6': 'Deep Thinker',
-    },
-    agentRoles: {
-      teacher: 'Teacher',
-      assistant: 'Assistant',
-      student: 'Student',
-    },
-    agentDescriptions: {
-      'default-1': 'Lead teacher with clear and structured explanations',
-      'default-2': 'Supports learning and helps clarify key points',
-      'default-3': 'Brings humor and energy to the classroom',
-      'default-4': 'Always curious, loves asking why and how',
-      'default-5': 'Diligently records and organizes class notes',
-      'default-6': 'Thinks deeply and explores the essence of topics',
-    },
-    close: 'Close',
-    save: 'Save',
-    // Provider settings
-    providers: 'LLM',
-    addProviderDescription: 'Add custom model providers to extend available AI models',
-    providerNames: {
-      openai: 'OpenAI',
-      anthropic: 'Claude',
-      google: 'Gemini',
-      deepseek: 'DeepSeek',
-      qwen: 'Qwen',
-      kimi: 'Kimi',
-      minimax: 'MiniMax',
-      glm: 'GLM',
-      siliconflow: 'SiliconFlow',
-    },
-    providerTypes: {
-      openai: 'OpenAI Protocol',
-      anthropic: 'Claude Protocol',
-      google: 'Gemini Protocol',
-    },
-    modelCount: 'models',
-    modelSingular: 'model',
-    defaultModel: 'Default Model',
-    webSearch: 'Web Search',
-    mcp: 'MCP',
-    knowledgeBase: 'Knowledge Base',
-    documentParser: 'Document Parser',
-    conversationSettings: 'Conversation',
-    keyboardShortcuts: 'Shortcuts',
-    generalSettings: 'General',
-    systemSettings: 'System',
-    addProvider: 'Add',
-    importFromClipboard: 'Import from Clipboard',
-    apiSecret: 'API Key',
-    apiHost: 'Base URL',
-    requestUrl: 'Request URL',
-    models: 'Models',
-    addModel: 'New',
-    reset: 'Reset',
-    fetch: 'Fetch',
-    connectionSuccess: 'Connection successful',
-    connectionFailed: 'Connection failed',
-    // Model capabilities
-    capabilities: {
-      vision: 'Vision',
-      tools: 'Tools',
-      streaming: 'Streaming',
-    },
-    contextWindow: 'Context',
-    contextShort: 'ctx',
-    outputWindow: 'Output',
-    // Provider management
-    addProviderButton: 'Add',
-    addProviderDialog: 'Add Model Provider',
-    providerName: 'Name',
-    providerNamePlaceholder: 'e.g., My OpenAI Proxy',
-    providerNameRequired: 'Please enter provider name',
-    providerApiMode: 'API Mode',
-    apiModeOpenAI: 'OpenAI Protocol',
-    apiModeAnthropic: 'Claude Protocol',
-    apiModeGoogle: 'Gemini Protocol',
-    defaultBaseUrl: 'Default Base URL',
-    providerIcon: 'Provider Icon URL',
-    requiresApiKey: 'Requires API Key',
-    deleteProvider: 'Delete Provider',
-    deleteProviderConfirm: 'Are you sure you want to delete this provider?',
-    cannotDeleteBuiltIn: 'Cannot delete built-in provider',
-    resetToDefault: 'Reset to Default',
-    resetToDefaultDescription:
-      'Restore model list to default configuration (API key and Base URL will be preserved)',
-    resetConfirmDescription:
-      'This will remove all custom models and restore the built-in default model list. API key and Base URL will be preserved.',
-    confirmReset: 'Confirm Reset',
-    resetSuccess: 'Successfully reset to default configuration',
-    saveSuccess: 'Settings saved',
-    saveFailed: 'Failed to save settings, please try again',
-    cannotDeleteBuiltInModel: 'Cannot delete built-in model',
-    cannotEditBuiltInModel: 'Cannot edit built-in model',
-    modelIdRequired: 'Please enter model ID',
-    noModelsAvailable: 'No models available for testing',
-    providerMetadata: 'Provider Metadata',
-    // Model editing
-    editModel: 'Edit Model',
-    editModelDescription: 'Edit model configuration and capabilities',
-    addNewModel: 'New Model',
-    addNewModelDescription: 'Add a new model configuration',
-    modelId: 'Model ID',
-    modelIdPlaceholder: 'e.g., gpt-4o',
-    modelName: 'Display Name',
-    modelNamePlaceholder: 'Optional',
-    modelCapabilities: 'Capabilities',
-    advancedSettings: 'Advanced Settings',
-    contextWindowLabel: 'Context Window',
-    contextWindowPlaceholder: 'e.g., 128000',
-    outputWindowLabel: 'Max Output Tokens',
-    outputWindowPlaceholder: 'e.g., 4096',
-    testModel: 'Test Model',
-    deleteModel: 'Delete',
-    cancelEdit: 'Cancel',
-    saveModel: 'Save',
-    modelsManagementDescription:
-      'Manage models for this provider. To select the active model, go to "General".',
-    // General settings
-    howToUse: 'How to Use',
-    step1ConfigureProvider:
-      'Go to "Model Providers", select or add a provider, and configure connection settings (API key, Base URL, etc.)',
-    step2SelectModel: 'Select the model you want to use in "Active Model" below',
-    step3StartUsing: 'After saving, the system will use your selected model',
-    activeModel: 'Active Model',
-    activeModelDescription: 'Select the model for AI conversations and content generation',
-    selectModel: 'Select Model',
-    searchModels: 'Search models',
-    noModelsFound: 'No matching models found',
-    noConfiguredProviders: 'No configured providers',
-    configureProvidersFirst:
-      'Please configure provider connection settings in "Model Providers" on the left',
-    currentlyUsing: 'Currently using',
-    // TTS settings
-    ttsSettings: 'Text-to-Speech',
-    // ASR settings
-    asrSettings: 'Speech Recognition',
-    // Audio settings (legacy)
-    audioSettings: 'Audio Settings',
-    ttsSection: 'Text-to-Speech (TTS)',
-    asrSection: 'Automatic Speech Recognition (ASR)',
-    ttsDescription: 'TTS (Text-to-Speech) - Convert text to speech',
-    asrDescription: 'ASR (Automatic Speech Recognition) - Convert speech to text',
-    enableTTS: 'Enable Text-to-Speech',
-    ttsEnabledDescription: 'When enabled, speech audio will be generated during course creation',
-    ttsVoiceConfigHint:
-      'Per-agent voice can be configured in "Classroom Role Config" on the homepage',
-    enableASR: 'Enable Speech Recognition',
-    asrEnabledDescription: 'When enabled, students can use microphone for voice input',
-    ttsProvider: 'TTS Provider',
-    ttsLanguageFilter: 'Language Filter',
-    allLanguages: 'All Languages',
-    ttsVoice: 'Voice',
-    ttsSpeed: 'Speed',
-    ttsBaseUrl: 'Base URL',
-    ttsApiKey: 'API Key',
-    doubaoAppId: 'App ID',
-    doubaoAccessKey: 'Access Key',
-    asrProvider: 'ASR Provider',
-    asrLanguage: 'Recognition Language',
-    asrBaseUrl: 'Base URL',
-    asrApiKey: 'API Key',
-    enterApiKey: 'Enter API Key',
-    enterCustomBaseUrl: 'Enter custom Base URL',
-    browserNativeNote: 'Browser Native ASR requires no configuration and is completely free',
-    // Audio provider names
-    providerOpenAITTS: 'OpenAI TTS (gpt-4o-mini-tts)',
-    providerAzureTTS: 'Azure TTS',
-    providerGLMTTS: 'GLM TTS',
-    providerQwenTTS: 'Qwen TTS (Alibaba Cloud Bailian)',
-    providerDoubaoTTS: 'Doubao TTS 2.0 (Volcengine)',
-    providerElevenLabsTTS: 'ElevenLabs TTS',
-    providerMiniMaxTTS: 'MiniMax TTS',
-    providerBrowserNativeTTS: 'Browser Native TTS',
-    providerOpenAIWhisper: 'OpenAI ASR (gpt-4o-mini-transcribe)',
-    providerBrowserNative: 'Browser Native ASR',
-    providerQwenASR: 'Qwen ASR (Alibaba Cloud Bailian)',
-    providerUnpdf: 'unpdf (Built-in)',
-    providerMinerU: 'MinerU',
-    browserNativeTTSNote:
-      'Browser Native TTS requires no configuration and is completely free, using system built-in voices',
-    testTTS: 'Test TTS',
-    testASR: 'Test ASR',
-    testSuccess: 'Test Successful',
-    testFailed: 'Test Failed',
-    ttsTestText: 'TTS Test Text',
-    ttsTestSuccess: 'TTS test successful, audio played',
-    ttsTestFailed: 'TTS test failed',
-    asrTestSuccess: 'Speech recognition successful',
-    asrTestFailed: 'Speech recognition failed',
-    asrResult: 'Recognition Result',
-    asrNotSupported: 'Browser does not support Speech Recognition API',
-    browserTTSNotSupported: 'Browser does not support Speech Synthesis API',
-    browserTTSNoVoices: 'Current browser has no available TTS voices',
-    microphoneAccessDenied: 'Microphone access denied',
-    microphoneAccessFailed: 'Failed to access microphone',
-    asrResultPlaceholder: 'Recognition result will be displayed after recording',
-    useThisProvider: 'Use This Provider',
-    fetchVoices: 'Fetch Voice List',
-    fetchingVoices: 'Fetching...',
-    voicesFetched: 'Voices fetched',
-    fetchVoicesFailed: 'Failed to fetch voices',
-    voiceApiKeyRequired: 'API Key required',
-    voiceBaseUrlRequired: 'Base URL required',
-    ttsTestTextPlaceholder: 'Enter text to convert',
-    ttsTestTextDefault: 'Hello, this is a test speech.',
-    startRecording: 'Start Recording',
-    stopRecording: 'Stop Recording',
-    recording: 'Recording...',
-    transcribing: 'Transcribing...',
-    transcriptionResult: 'Transcription Result',
-    noTranscriptionResult: 'No transcription result',
-    baseUrlOptional: 'Base URL (Optional)',
-    defaultValue: 'Default',
-    // TTS Voice descriptions (OpenAI)
-    voiceMarin: 'Recommended - Best Quality',
-    voiceCedar: 'Recommended - Best Quality',
-    voiceAlloy: 'Neutral, Balanced',
-    voiceAsh: 'Steady, Professional',
-    voiceBallad: 'Elegant, Lyrical',
-    voiceCoral: 'Warm, Friendly',
-    voiceEcho: 'Male, Clear',
-    voiceFable: 'Narrative, Vivid',
-    voiceNova: 'Female, Bright',
-    voiceOnyx: 'Male, Deep',
-    voiceSage: 'Wise, Composed',
-    voiceShimmer: 'Female, Soft',
-    voiceVerse: 'Natural, Smooth',
-    // TTS Voice descriptions (GLM)
-    glmVoiceTongtong: 'Default voice',
-    glmVoiceChuichui: 'Chuichui voice',
-    glmVoiceXiaochen: 'Xiaochen voice',
-    glmVoiceJam: 'Jam voice',
-    glmVoiceKazi: 'Kazi voice',
-    glmVoiceDouji: 'Douji voice',
-    glmVoiceLuodo: 'Luodo voice',
-    // TTS Voice descriptions (Qwen)
-    qwenVoiceCherry: 'Sunny, warm and natural',
-    qwenVoiceSerena: 'Gentle and soft',
-    qwenVoiceEthan: 'Energetic and vibrant',
-    qwenVoiceChelsie: 'Anime virtual girlfriend',
-    qwenVoiceMomo: 'Playful and cheerful',
-    qwenVoiceVivian: 'Cute and sassy',
-    qwenVoiceMoon: 'Cool and handsome',
-    qwenVoiceMaia: 'Intellectual and gentle',
-    qwenVoiceKai: 'A SPA for your ears',
-    qwenVoiceNofish: "Designer who can't pronounce retroflex sounds",
-    qwenVoiceBella: "Little loli who doesn't get drunk",
-    qwenVoiceJennifer: 'Brand-level, cinematic American female voice',
-    qwenVoiceRyan: 'Fast-paced, dramatic performance',
-    qwenVoiceKaterina: 'Mature lady with memorable rhythm',
-    qwenVoiceAiden: 'American boy who masters cooking',
-    qwenVoiceEldricSage: 'Steady and wise elder',
-    qwenVoiceMia: 'Gentle as spring water, well-behaved as snow',
-    qwenVoiceMochi: 'Smart little adult with childlike innocence',
-    qwenVoiceBellona: 'Loud voice, clear pronunciation, vivid characters',
-    qwenVoiceVincent: 'Unique hoarse voice telling tales of war and honor',
-    qwenVoiceBunny: 'Super cute loli',
-    qwenVoiceNeil: 'Professional news anchor',
-    qwenVoiceElias: 'Professional instructor',
-    qwenVoiceArthur: 'Simple voice soaked by years and dry tobacco',
-    qwenVoiceNini: 'Soft and sticky voice like glutinous rice cake',
-    qwenVoiceEbona: 'Her whisper is like a rusty key',
-    qwenVoiceSeren: 'Gentle and soothing voice to help you sleep',
-    qwenVoicePip: 'Naughty but full of childlike innocence',
-    qwenVoiceStella: 'Sweet confused girl voice that becomes just when shouting',
-    qwenVoiceBodega: 'Enthusiastic Spanish uncle',
-    qwenVoiceSonrisa: 'Enthusiastic Latin American lady',
-    qwenVoiceAlek: 'Cold of battle nation, warm under woolen coat',
-    qwenVoiceDolce: 'Lazy Italian uncle',
-    qwenVoiceSohee: 'Gentle, cheerful Korean unnie',
-    qwenVoiceOnoAnna: 'Mischievous childhood friend',
-    qwenVoiceLenn: 'Rational German youth who wears suit and listens to post-punk',
-    qwenVoiceEmilien: 'Romantic French big brother',
-    qwenVoiceAndre: 'Magnetic, natural and calm male voice',
-    qwenVoiceRadioGol: 'Football poet Rádio Gol!',
-    qwenVoiceJada: 'Lively Shanghai lady',
-    qwenVoiceDylan: 'Beijing boy',
-    qwenVoiceLi: 'Patient yoga teacher',
-    qwenVoiceMarcus: 'Broad face, short words, solid heart - old Shaanxi taste',
-    qwenVoiceRoy: 'Humorous and straightforward Taiwanese boy',
-    qwenVoicePeter: 'Tianjin cross-talk professional supporter',
-    qwenVoiceSunny: 'Sweet Sichuan girl',
-    qwenVoiceEric: 'Chengdu gentleman',
-    qwenVoiceRocky: 'Humorous Hong Kong guy',
-    qwenVoiceKiki: 'Sweet Hong Kong girl',
-    // ASR Language names (native forms - autoglossonyms)
-    lang_auto: 'Auto Detect',
-    lang_zh: '中文',
-    lang_yue: '粤語',
-    lang_en: 'English',
-    lang_ja: '日本語',
-    lang_ko: '한국어',
-    lang_es: 'Español',
-    lang_fr: 'Français',
-    lang_de: 'Deutsch',
-    lang_ru: 'Русский',
-    lang_ar: 'العربية',
-    lang_pt: 'Português',
-    lang_it: 'Italiano',
-    lang_af: 'Afrikaans',
-    lang_hy: 'Հայերեն',
-    lang_az: 'Azərbaycan',
-    lang_be: 'Беларуская',
-    lang_bs: 'Bosanski',
-    lang_bg: 'Български',
-    lang_ca: 'Català',
-    lang_hr: 'Hrvatski',
-    lang_cs: 'Čeština',
-    lang_da: 'Dansk',
-    lang_nl: 'Nederlands',
-    lang_et: 'Eesti',
-    lang_fi: 'Suomi',
-    lang_gl: 'Galego',
-    lang_el: 'Ελληνικά',
-    lang_he: 'עברית',
-    lang_hi: 'हिन्दी',
-    lang_hu: 'Magyar',
-    lang_is: 'Íslenska',
-    lang_id: 'Bahasa Indonesia',
-    lang_kn: 'ಕನ್ನಡ',
-    lang_kk: 'Қазақша',
-    lang_lv: 'Latviešu',
-    lang_lt: 'Lietuvių',
-    lang_mk: 'Македонски',
-    lang_ms: 'Bahasa Melayu',
-    lang_mr: 'मराठी',
-    lang_mi: 'Te Reo Māori',
-    lang_ne: 'नेपाली',
-    lang_no: 'Norsk',
-    lang_fa: 'فارسی',
-    lang_pl: 'Polski',
-    lang_ro: 'Română',
-    lang_sr: 'Српски',
-    lang_sk: 'Slovenčina',
-    lang_sl: 'Slovenščina',
-    lang_sw: 'Kiswahili',
-    lang_sv: 'Svenska',
-    lang_tl: 'Tagalog',
-    lang_fil: 'Filipino',
-    lang_ta: 'தமிழ்',
-    lang_th: 'ไทย',
-    lang_tr: 'Türkçe',
-    lang_uk: 'Українська',
-    lang_ur: 'اردو',
-    lang_vi: 'Tiếng Việt',
-    lang_cy: 'Cymraeg',
-    // BCP-47 format language codes (for Web Speech API)
-    'lang_zh-CN': '中文（简体，中国）',
-    'lang_zh-TW': '中文（繁體，台灣）',
-    'lang_zh-HK': '粵語（香港）',
-    'lang_yue-Hant-HK': '粵語（繁體）',
-    'lang_en-US': 'English (United States)',
-    'lang_en-GB': 'English (United Kingdom)',
-    'lang_en-AU': 'English (Australia)',
-    'lang_en-CA': 'English (Canada)',
-    'lang_en-IN': 'English (India)',
-    'lang_en-NZ': 'English (New Zealand)',
-    'lang_en-ZA': 'English (South Africa)',
-    'lang_ja-JP': '日本語（日本）',
-    'lang_ko-KR': '한국어（대한민국）',
-    'lang_de-DE': 'Deutsch (Deutschland)',
-    'lang_fr-FR': 'Français (France)',
-    'lang_es-ES': 'Español (España)',
-    'lang_es-MX': 'Español (México)',
-    'lang_es-AR': 'Español (Argentina)',
-    'lang_es-CO': 'Español (Colombia)',
-    'lang_it-IT': 'Italiano (Italia)',
-    'lang_pt-BR': 'Português (Brasil)',
-    'lang_pt-PT': 'Português (Portugal)',
-    'lang_ru-RU': 'Русский (Россия)',
-    'lang_nl-NL': 'Nederlands (Nederland)',
-    'lang_pl-PL': 'Polski (Polska)',
-    'lang_cs-CZ': 'Čeština (Česko)',
-    'lang_da-DK': 'Dansk (Danmark)',
-    'lang_fi-FI': 'Suomi (Suomi)',
-    'lang_sv-SE': 'Svenska (Sverige)',
-    'lang_no-NO': 'Norsk (Norge)',
-    'lang_tr-TR': 'Türkçe (Türkiye)',
-    'lang_el-GR': 'Ελληνικά (Ελλάδα)',
-    'lang_hu-HU': 'Magyar (Magyarország)',
-    'lang_ro-RO': 'Română (România)',
-    'lang_sk-SK': 'Slovenčina (Slovensko)',
-    'lang_bg-BG': 'Български (България)',
-    'lang_hr-HR': 'Hrvatski (Hrvatska)',
-    'lang_ca-ES': 'Català (Espanya)',
-    'lang_ar-SA': 'العربية (السعودية)',
-    'lang_ar-EG': 'العربية (مصر)',
-    'lang_he-IL': 'עברית (ישראל)',
-    'lang_hi-IN': 'हिन्दी (भारत)',
-    'lang_th-TH': 'ไทย (ประเทศไทย)',
-    'lang_vi-VN': 'Tiếng Việt (Việt Nam)',
-    'lang_id-ID': 'Bahasa Indonesia (Indonesia)',
-    'lang_ms-MY': 'Bahasa Melayu (Malaysia)',
-    'lang_fil-PH': 'Filipino (Pilipinas)',
-    'lang_af-ZA': 'Afrikaans (Suid-Afrika)',
-    'lang_uk-UA': 'Українська (Україна)',
-    // PDF settings
-    pdfSettings: 'PDF Parsing',
-    pdfParsingSettings: 'PDF Parsing Settings',
-    pdfDescription:
-      'Choose PDF parsing engine with support for text extraction, image processing, and table recognition',
-    pdfProvider: 'PDF Parser',
-    pdfFeatures: 'Supported Features',
-    pdfApiKey: 'API Key',
-    pdfBaseUrl: 'Base URL',
-    mineruDescription:
-      'MinerU is a commercial PDF parsing service that supports advanced features such as table extraction, formula recognition, and layout analysis.',
-    mineruApiKeyRequired: 'You need to apply for an API Key on the MinerU website before use.',
-    mineruWarning: 'Warning',
-    mineruCostWarning:
-      'MinerU is a commercial service and may incur fees. Please check the MinerU website for pricing details.',
-    enterMinerUApiKey: 'Enter MinerU API Key',
-    mineruLocalDescription:
-      'MinerU supports local deployment with advanced PDF parsing (tables, formulas, layout analysis). Requires deploying MinerU service first.',
-    mineruServerAddress: 'Local MinerU server address (e.g., http://localhost:8080)',
-    mineruApiKeyOptional: 'Only required if server has authentication enabled',
-    optionalApiKey: 'Optional API Key',
-    featureText: 'Text Extraction',
-    featureImages: 'Image Extraction',
-    featureTables: 'Table Extraction',
-    featureFormulas: 'Formula Recognition',
-    featureLayoutAnalysis: 'Layout Analysis',
-    featureMetadata: 'Metadata',
-    // Image Generation settings
-    enableImageGeneration: 'Enable AI Image Generation',
-    imageGenerationDisabledHint:
-      'When enabled, images will be auto-generated during course creation',
-    imageSettings: 'Image Generation',
-    imageSection: 'Text to Image',
-    imageProvider: 'Image Generation Provider',
-    imageModel: 'Image Generation Model',
-    providerSeedream: 'Seedream (ByteDance)',
-    providerQwenImage: 'Qwen Image (Alibaba)',
-    providerNanoBanana: 'Nano Banana (Gemini)',
-    providerMiniMaxImage: 'MiniMax Image',
-    providerGrokImage: 'Grok Image (xAI)',
-    testImageGeneration: 'Test Image Generation',
-    testImageConnectivity: 'Test Connection',
-    imageConnectivitySuccess: 'Image service connected successfully',
-    imageConnectivityFailed: 'Image service connection failed',
-    imageTestSuccess: 'Image generation test succeeded',
-    imageTestFailed: 'Image generation test failed',
-    imageTestPromptPlaceholder: 'Enter image description to test',
-    imageTestPromptDefault: 'A cute cat sitting on a desk',
-    imageGenerating: 'Generating image...',
-    imageGenerationFailed: 'Image generation failed',
-    // Video Generation settings
-    enableVideoGeneration: 'Enable AI Video Generation',
-    videoGenerationDisabledHint:
-      'When enabled, videos will be auto-generated during course creation',
-    videoSettings: 'Video Generation',
-    videoSection: 'Text to Video',
-    videoProvider: 'Video Generation Provider',
-    videoModel: 'Video Generation Model',
-    providerSeedance: 'Seedance (ByteDance)',
-    providerKling: 'Kling (Kuaishou)',
-    providerVeo: 'Veo (Google)',
-    providerSora: 'Sora (OpenAI)',
-    providerMiniMaxVideo: 'MiniMax Video',
-    providerGrokVideo: 'Grok Video (xAI)',
-    testVideoGeneration: 'Test Video Generation',
-    testVideoConnectivity: 'Test Connection',
-    videoConnectivitySuccess: 'Video service connected successfully',
-    videoConnectivityFailed: 'Video service connection failed',
-    testingConnection: 'Testing...',
-    videoTestSuccess: 'Video generation test succeeded',
-    videoTestFailed: 'Video generation test failed',
-    videoTestPromptDefault: 'A cute cat walking on a desk',
-    videoGenerating: 'Generating video (est. 1-2 min)...',
-    videoGenerationWarning: 'Video generation usually takes 1-2 minutes, please be patient',
-    mediaRetry: 'Retry',
-    mediaContentSensitive: 'Sorry, this content triggered a safety check.',
-    mediaGenerationDisabled: 'Generation disabled in settings',
-    // Agent settings (kept with main settings block above)
-    singleAgent: 'Single Agent',
-    multiAgent: 'Multi-Agent',
-    selectAgents: 'Select Agents',
-    noVisionWarning:
-      'Current model does not support vision. Images can still be placed in slides, but the model cannot understand image content to optimize selection and layout',
-    // Server provider configuration
-    serverConfigured: 'Server',
-    serverConfiguredNotice:
-      'Admin has configured an API key for this provider on the server. You can use it directly or enter your own key to override.',
-    optionalOverride: 'Optional — leave empty to use server config',
-    // Access code
-    setupNeeded: 'Setup required',
-    modelNotConfigured: 'Please select a model to get started',
-    // Clear cache
-    dangerZone: 'Danger Zone',
-    clearCache: 'Clear Local Cache',
-    clearCacheDescription:
-      'Delete all locally stored data, including classroom records, chat history, audio cache, and app settings. This action cannot be undone.',
-    clearCacheConfirmTitle: 'Are you sure you want to clear all cache?',
-    clearCacheConfirmDescription:
-      'This will permanently delete all of the following data and cannot be recovered:',
-    clearCacheConfirmItems:
-      'Classrooms & scenes, Chat history, Audio & image cache, App settings & preferences',
-    clearCacheConfirmInput: 'Type "DELETE" to continue',
-    clearCacheConfirmPhrase: 'DELETE',
-    clearCacheButton: 'Permanently Delete All Data',
-    clearCacheSuccess: 'Cache cleared, page will refresh shortly',
-    clearCacheFailed: 'Failed to clear cache, please try again',
-    // Web Search settings
-    webSearchSettings: 'Web Search',
-    webSearchApiKey: 'Tavily API Key',
-    webSearchApiKeyPlaceholder: 'Enter your Tavily API Key',
-    webSearchApiKeyPlaceholderServer: 'Server key configured, optionally override',
-    webSearchApiKeyHint: 'Get an API key from tavily.com for web search',
-    webSearchBaseUrl: 'Base URL',
-    webSearchServerConfigured: 'Server-side Tavily API key is configured',
-    optional: 'Optional',
-  },
-  profile: {
-    title: 'Profile',
-    defaultNickname: 'Student',
-    chooseAvatar: 'Choose Avatar',
-    uploadAvatar: 'Upload',
-    bioPlaceholder: 'Tell us about yourself — the AI teacher will personalize lessons for you...',
-    avatarHint: 'Your avatar will appear in classroom discussions and chats',
-    fileTooLarge: 'Image too large — please choose one under 5 MB',
-    invalidFileType: 'Please select an image file',
-    editTooltip: 'Click to edit profile',
-  },
-  media: {
-    imageCapability: 'Image Generation',
-    imageHint: 'Generate images in slides',
-    videoCapability: 'Video Generation',
-    videoHint: 'Generate videos in slides',
-    ttsCapability: 'Text-to-Speech',
-    ttsHint: 'AI teacher speaks aloud',
-    asrCapability: 'Speech Recognition',
-    asrHint: 'Voice input for discussion',
-    provider: 'Provider',
-    model: 'Model',
-    voice: 'Voice',
-    speed: 'Speed',
-    language: 'Language',
-  },
-} as const;
diff --git a/lib/i18n/stage.ts b/lib/i18n/stage.ts
deleted file mode 100644
index 0a376ca10..000000000
--- a/lib/i18n/stage.ts
+++ /dev/null
@@ -1,298 +0,0 @@
-export const stageZhCN = {
-  stage: {
-    currentScene: '当前场景',
-    generating: '生成中...',
-    paused: '已暂停',
-    generationFailed: '生成失败',
-    confirmSwitchTitle: '切换页面',
-    confirmSwitchMessage: '当前话题正在进行中，切换页面将结束当前话题。确定要切换吗？',
-    generatingNextPage: '场景正在生成，请稍候...',
-    fullscreen: '全屏',
-    exitFullscreen: '退出全屏',
-  },
-  whiteboard: {
-    title: '互动白板',
-    open: '打开白板',
-    clear: '清空白板',
-    minimize: '最小化白板',
-    ready: '白板已就绪',
-    readyHint: 'AI 添加元素后将在此显示',
-    clearSuccess: '白板已清空',
-    clearError: '清空白板失败：',
-    resetView: '重置视图',
-    restoreError: '恢复白板失败：',
-    history: '历史记录',
-    restore: '恢复',
-    noHistory: '暂无历史记录',
-    restored: '已恢复白板内容',
-    elementCount: '{count} 个元素',
-  },
-  quiz: {
-    title: '随堂测验',
-    subtitle: '检测你的学习成果',
-    questionsCount: '道题',
-    totalPrefix: '共',
-    pointsSuffix: '分',
-    startQuiz: '开始答题',
-    multipleChoiceHint: '（多选题，请选择所有正确答案）',
-    inputPlaceholder: '请在此输入你的回答...',
-    charCount: '字',
-    yourAnswer: '你的回答：',
-    notAnswered: '未作答',
-    aiComment: 'AI 点评',
-    singleChoice: '单选',
-    multipleChoice: '多选',
-    shortAnswer: '简答',
-    analysis: '解析：',
-    excellent: '优秀！',
-    keepGoing: '继续加油！',
-    needsReview: '需要复习',
-    correct: '正确',
-    incorrect: '错误',
-    answering: '答题中',
-    submitAnswers: '提交答案',
-    aiGrading: 'AI 正在批改中...',
-    aiGradingWait: '请稍候，正在分析你的答案',
-    quizReport: '答题报告',
-    retry: '重新答题',
-  },
-  roundtable: {
-    teacher: '教师',
-    you: '你',
-    inputPlaceholder: '输入你的消息...',
-    listening: '录音中...',
-    processing: '处理中...',
-    noSpeechDetected: '未检测到语音，请重试',
-    discussionEnded: '讨论已结束',
-    qaEnded: '问答已结束',
-    thinking: '思考中',
-    yourTurn: '轮到你发言了',
-    stopDiscussion: '结束讨论',
-    autoPlay: '自动播放',
-    autoPlayOff: '关闭自动播放',
-    speed: '倍速',
-    voiceInput: '语音输入',
-    voiceInputDisabled: '语音输入已禁用',
-    textInput: '文字输入',
-    stopRecording: '停止录音',
-    startRecording: '开始录音',
-  },
-  pbl: {
-    legacyFormat: '此PBL场景使用旧格式，请重新生成课程',
-    emptyProject: 'PBL项目尚未生成，请通过课程生成创建',
-    roleSelection: {
-      title: '选择你的角色',
-      description: '选择一个角色开始项目协作',
-    },
-    workspace: {
-      restart: '重新开始',
-      confirmRestart: '确定重置进度？',
-      confirm: '确定',
-      cancel: '取消',
-    },
-    issueboard: {
-      title: '任务看板',
-      noIssues: '暂无任务',
-      statusDone: '已完成',
-      statusActive: '进行中',
-      statusPending: '待处理',
-    },
-    chat: {
-      title: '项目讨论',
-      currentIssue: '当前任务',
-      mentionHint: '使用 @question 提问，@judge 提交评审',
-      placeholder: '输入消息...',
-      send: '发送',
-      welcomeMessage:
-        '你好！我是本任务的提问助手，当前任务：「{title}」\n\n为了帮助你开展工作，我准备了一些引导问题：\n\n{questions}\n\n随时可以 @question 向我提问！',
-      issueCompleteMessage: '任务「{completed}」已完成！进入下一个任务：「{next}」',
-      allCompleteMessage: '🎉 所有任务都已完成！项目做得很棒！',
-    },
-    guide: {
-      howItWorks: '如何参与项目',
-      help: '使用帮助',
-      title: '使用帮助',
-      step1: {
-        title: '第一步：选择角色',
-        desc: '项目生成后，从角色列表中选择一个角色（标记为🟢的非系统角色）',
-      },
-      step2: {
-        title: '第二步：完成任务',
-        desc: '每个任务代表一个学习目标：',
-        s1: {
-          title: '查看当前任务',
-          desc: '查看任务的标题、描述、负责人',
-        },
-        s2: {
-          title: '获取指导',
-          example: '@question 我应该从哪里开始？\n@question 如何实现这个功能？',
-          desc: '提问助手会提供引导性问题和提示（不直接给答案）',
-        },
-        s3: {
-          title: '提交作品',
-          example: '@judge 我已经完成了，请检查',
-          desc: '评审助手会评估你的工作并给出反馈：',
-          complete: '自动进入下一个任务',
-          revision: '根据反馈改进',
-        },
-      },
-      step3: {
-        title: '第三步：完成项目',
-        desc: '所有任务完成后，系统会显示「🎉 项目已完成！」',
-      },
-    },
-  },
-  share: {
-    notReady: '生成完成后可分享',
-  },
-} as const;
-
-export const stageEnUS = {
-  stage: {
-    currentScene: 'Current Scene',
-    generating: 'Generating...',
-    paused: 'Paused',
-    generationFailed: 'Generation failed',
-    confirmSwitchTitle: 'Switch Scene',
-    confirmSwitchMessage:
-      'A topic is currently in progress. Switching scenes will end the current topic. Are you sure?',
-    generatingNextPage: 'Scene is being generated, please wait...',
-    fullscreen: 'Fullscreen',
-    exitFullscreen: 'Exit Fullscreen',
-  },
-  whiteboard: {
-    title: 'Interactive Whiteboard',
-    open: 'Open Whiteboard',
-    clear: 'Clear Whiteboard',
-    minimize: 'Minimize Whiteboard',
-    ready: 'Whiteboard is ready',
-    readyHint: 'Elements will appear here when added by AI',
-    clearSuccess: 'Whiteboard cleared successfully',
-    clearError: 'Failed to clear whiteboard: ',
-    resetView: 'Reset View',
-    restoreError: 'Failed to restore whiteboard: ',
-    history: 'History',
-    restore: 'Restore',
-    noHistory: 'No history yet',
-    restored: 'Whiteboard restored',
-    elementCount: '{count} elements',
-  },
-  quiz: {
-    title: 'Quiz',
-    subtitle: 'Test your knowledge',
-    questionsCount: 'questions',
-    totalPrefix: '',
-    pointsSuffix: 'pts',
-    startQuiz: 'Start Quiz',
-    multipleChoiceHint: '(Multiple choice — select all correct answers)',
-    inputPlaceholder: 'Type your answer here...',
-    charCount: 'chars',
-    yourAnswer: 'Your answer:',
-    notAnswered: 'Not answered',
-    aiComment: 'AI Feedback',
-    singleChoice: 'Single',
-    multipleChoice: 'Multiple',
-    shortAnswer: 'Short answer',
-    analysis: 'Analysis: ',
-    excellent: 'Excellent!',
-    keepGoing: 'Keep going!',
-    needsReview: 'Needs review',
-    correct: 'correct',
-    incorrect: 'incorrect',
-    answering: 'In Progress',
-    submitAnswers: 'Submit Answers',
-    aiGrading: 'AI is grading...',
-    aiGradingWait: 'Please wait, analyzing your answers',
-    quizReport: 'Quiz Report',
-    retry: 'Retry',
-  },
-  roundtable: {
-    teacher: 'TEACHER',
-    you: 'YOU',
-    inputPlaceholder: 'Type your message...',
-    listening: 'Listening...',
-    processing: 'Processing...',
-    noSpeechDetected: 'No speech detected, please try again',
-    discussionEnded: 'Discussion ended',
-    qaEnded: 'Q&A ended',
-    thinking: 'Thinking',
-    yourTurn: 'Your turn',
-    stopDiscussion: 'Stop Discussion',
-    autoPlay: 'Auto-play',
-    autoPlayOff: 'Stop auto-play',
-    speed: 'Speed',
-    voiceInput: 'Voice input',
-    voiceInputDisabled: 'Voice input disabled',
-    textInput: 'Text input',
-    stopRecording: 'Stop recording',
-    startRecording: 'Start recording',
-  },
-  pbl: {
-    legacyFormat: 'This PBL scene uses a legacy format. Please regenerate the course.',
-    emptyProject: 'PBL project has not been generated yet. Please create via course generation.',
-    roleSelection: {
-      title: 'Choose Your Role',
-      description: 'Select a role to start collaborating on the project',
-    },
-    workspace: {
-      restart: 'Restart',
-      confirmRestart: 'Reset all progress?',
-      confirm: 'Confirm',
-      cancel: 'Cancel',
-    },
-    issueboard: {
-      title: 'Issue Board',
-      noIssues: 'No issues yet',
-      statusDone: 'Done',
-      statusActive: 'Active',
-      statusPending: 'Pending',
-    },
-    chat: {
-      title: 'Project Discussion',
-      currentIssue: 'Current Issue',
-      mentionHint: 'Use @question to ask, @judge to submit for review',
-      placeholder: 'Type a message...',
-      send: 'Send',
-      welcomeMessage:
-        'Hello! I\'m your Question Agent for this issue: "{title}"\n\nTo help guide your work, I\'ve prepared some questions for you:\n\n{questions}\n\nFeel free to @question me anytime if you need help or clarification!',
-      issueCompleteMessage: 'Issue "{completed}" completed! Moving to next issue: "{next}"',
-      allCompleteMessage: '🎉 All issues completed! Great work on the project!',
-    },
-    guide: {
-      howItWorks: 'How it works',
-      help: 'Help',
-      title: 'Help',
-      step1: {
-        title: 'Step 1: Choose a Role',
-        desc: 'After the project is generated, select a role from the list (non-system roles marked with 🟢)',
-      },
-      step2: {
-        title: 'Step 2: Complete Issues',
-        desc: 'Each issue represents a learning task:',
-        s1: {
-          title: 'View current Issue',
-          desc: "Check the issue's title, description, and assignee",
-        },
-        s2: {
-          title: 'Get guidance',
-          example: '@question Where should I start?\n@question How do I implement this feature?',
-          desc: 'The Question Agent provides guiding questions and hints (no direct answers)',
-        },
-        s3: {
-          title: 'Submit your work',
-          example: "@judge I'm done, please check my Notes",
-          desc: 'The Judge Agent evaluates your work and gives feedback:',
-          complete: 'Automatically moves to the next issue',
-          revision: 'Improve based on feedback',
-        },
-      },
-      step3: {
-        title: 'Step 3: Complete the Project',
-        desc: 'When all issues are done, the system displays "🎉 Project Complete!"',
-      },
-    },
-  },
-  share: {
-    notReady: 'Available after generation completes',
-  },
-} as const;
diff --git a/lib/i18n/types.ts b/lib/i18n/types.ts
index 6173b0be3..a58744507 100644
--- a/lib/i18n/types.ts
+++ b/lib/i18n/types.ts
@@ -1,3 +1,5 @@
-export type Locale = 'zh-CN' | 'en-US';
+import { supportedLocales } from './locales';
+
+export type Locale = (typeof supportedLocales)[number]['code'];
 
 export const defaultLocale: Locale = 'zh-CN';
diff --git a/package.json b/package.json
index 55835ca15..c27dba7ce 100644
--- a/package.json
+++ b/package.json
@@ -49,6 +49,8 @@
     "embla-carousel-react": "^8.6.0",
     "file-saver": "^2.0.5",
     "geist": "^1.7.0",
+    "i18next": "^26.0.1",
+    "i18next-resources-to-backend": "^1.2.1",
     "immer": "^11.1.3",
     "js-yaml": "^4.1.1",
     "jsonrepair": "^3.13.2",
@@ -80,6 +82,7 @@
     "radix-ui": "^1.4.3",
     "react": "19.2.3",
     "react-dom": "19.2.3",
+    "react-i18next": "^17.0.1",
     "shadcn": "^3.6.3",
     "sharp": "^0.34.5",
     "shiki": "^3.21.0",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index fac3752ea..7592f157b 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -98,6 +98,12 @@ importers:
       geist:
         specifier: ^1.7.0
         version: 1.7.0(next@16.1.2(@babel/core@7.29.0)(@opentelemetry/api@1.9.0)(@playwright/test@1.58.2)(react-dom@19.2.3(react@19.2.3))(react@19.2.3))
+      i18next:
+        specifier: ^26.0.1
+        version: 26.0.1(typescript@5.9.3)
+      i18next-resources-to-backend:
+        specifier: ^1.2.1
+        version: 1.2.1
       immer:
         specifier: ^11.1.3
         version: 11.1.4
@@ -191,6 +197,9 @@ importers:
       react-dom:
         specifier: 19.2.3
         version: 19.2.3(react@19.2.3)
+      react-i18next:
+        specifier: ^17.0.1
+        version: 17.0.1(i18next@26.0.1(typescript@5.9.3))(react-dom@19.2.3(react@19.2.3))(react@19.2.3)(typescript@5.9.3)
       shadcn:
         specifier: ^3.6.3
         version: 3.8.5(@cfworker/json-schema@4.1.1)(@types/node@20.19.37)(typescript@5.9.3)
@@ -281,7 +290,7 @@ importers:
         version: 9.39.4(jiti@2.6.1)
       eslint-config-next:
         specifier: 16.1.2
-        version: 16.1.2(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3)
+        version: 16.1.2(@typescript-eslint/parser@8.57.0(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3))(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3)
       prettier:
         specifier: 3.8.1
         version: 3.8.1
@@ -699,6 +708,10 @@ packages:
     resolution: {integrity: sha512-05WQkdpL9COIMz4LjTxGpPNCdlpyimKppYNoJ5Di5EUObifl8t4tuLuUBBZEpoLYOmfvIWrsp9fCl0HoPRVTdA==}
     engines: {node: '>=6.9.0'}
 
+  '@babel/runtime@7.29.2':
+    resolution: {integrity: sha512-JiDShH45zKHWyGe4ZNVRrCjBz8Nh9TMmZG1kh4QTK8hCBTWBi8Da+i7s1fJw7/lYpM4ccepSNfqzZ/QvABBi5g==}
+    engines: {node: '>=6.9.0'}
+
   '@babel/template@7.28.6':
     resolution: {integrity: sha512-YA6Ma2KsCdGb+WC6UpBVFJGXL58MDA6oyONbjyF/+5sBgxY/dwkhLogbMT2GXXyU84/IhRw/2D1Os1B/giz+BQ==}
     engines: {node: '>=6.9.0'}
@@ -5483,6 +5496,9 @@ packages:
   html-escaper@2.0.2:
     resolution: {integrity: sha512-H2iMtd0I4Mt5eYiapRdIDjp+XzelXQ0tFE4JS7YFwFevXXMmOp9myNrUvCg0D6ws8iqkRPBfKHgbwig1SmlLfg==}
 
+  html-parse-stringify@3.0.1:
+    resolution: {integrity: sha512-KknJ50kTInJ7qIScF3jeaFRpMpE8/lfiTdzf/twXyPBLAGrLRTmkz3AdTnKeh40X8k9L2fdYwEp/42WGXIRGcg==}
+
   html-url-attributes@3.0.1:
     resolution: {integrity: sha512-ol6UPyBWqsrO6EJySPz2O7ZSr856WDrEzM5zMqp+FJJLGMW35cLYmmZnl0vztAZxRUoNZJFTCohfjuIJ8I4QBQ==}
 
@@ -5520,6 +5536,17 @@ packages:
     engines: {node: '>=18'}
     hasBin: true
 
+  i18next-resources-to-backend@1.2.1:
+    resolution: {integrity: sha512-okHbVA+HZ7n1/76MsfhPqDou0fptl2dAlhRDu2ideXloRRduzHsqDOznJBef+R3DFZnbvWoBW+KxJ7fnFjd6Yw==}
+
+  i18next@26.0.1:
+    resolution: {integrity: sha512-vtz5sXU4+nkCm8yEU+JJ6yYIx0mkg9e68W0G0PXpnOsmzLajNsW5o28DJMqbajxfsfq0gV3XdrBudsDQnwxfsQ==}
+    peerDependencies:
+      typescript: ^5 || ^6
+    peerDependenciesMeta:
+      typescript:
+        optional: true
+
   iconv-lite@0.4.24:
     resolution: {integrity: sha512-v3MXnZAcvnywkTUEZomIActle7RXXeedOR31wwl7VlyoXO4Qi9arvSenNQWne1TcRwhCL1HwLI21bEqdpj8/rA==}
     engines: {node: '>=0.10.0'}
@@ -7706,6 +7733,22 @@ packages:
     peerDependencies:
       react: ^19.2.3
 
+  react-i18next@17.0.1:
+    resolution: {integrity: sha512-iG65FGnFHcYyHNuT01ukffYWCOBFTWSdVD8EZd/dCVWgtjFPObcSsvYYNwcsokO/rDcTb5d6D8Acv8MrOdm6Hw==}
+    peerDependencies:
+      i18next: '>= 26.0.1'
+      react: '>= 16.8.0'
+      react-dom: '*'
+      react-native: '*'
+      typescript: ^5 || ^6
+    peerDependenciesMeta:
+      react-dom:
+        optional: true
+      react-native:
+        optional: true
+      typescript:
+        optional: true
+
   react-is@16.13.1:
     resolution: {integrity: sha512-24e6ynE2H+OKt4kqsOvNd8kBpV65zoxbA4BVsEOB3ARVWQki/DHzaUoC5KuON/BiccDaCCTZBuOcfZs70kR8bQ==}
 
@@ -8963,6 +9006,10 @@ packages:
       jsdom:
         optional: true
 
+  void-elements@3.1.0:
+    resolution: {integrity: sha512-Dhxzh5HZuiHQhbvTW9AMetFfBHDMYpo23Uo9btPXgdYP+3T5S+p+jgNy7spra+veYhBP2dCSgxR/i2Y02h5/6w==}
+    engines: {node: '>=0.10.0'}
+
   vue-eslint-parser@2.0.3:
     resolution: {integrity: sha512-ZezcU71Owm84xVF6gfurBQUGg8WQ+WZGxgDEQu1IHFBZNx7BFZg3L1yHxrCBNNwbwFtE1GuvfJKMtb6Xuwc/Bw==}
     engines: {node: '>=4'}
@@ -9620,6 +9667,8 @@ snapshots:
 
   '@babel/runtime@7.28.6': {}
 
+  '@babel/runtime@7.29.2': {}
+
   '@babel/template@7.28.6':
     dependencies:
       '@babel/code-frame': 7.29.0
@@ -13759,13 +13808,13 @@ snapshots:
 
   escape-string-regexp@5.0.0: {}
 
-  eslint-config-next@16.1.2(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3):
+  eslint-config-next@16.1.2(@typescript-eslint/parser@8.57.0(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3))(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3):
     dependencies:
       '@next/eslint-plugin-next': 16.1.2
       eslint: 9.39.4(jiti@2.6.1)
       eslint-import-resolver-node: 0.3.9
       eslint-import-resolver-typescript: 3.10.1(eslint-plugin-import@2.32.0)(eslint@9.39.4(jiti@2.6.1))
-      eslint-plugin-import: 2.32.0(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1))
+      eslint-plugin-import: 2.32.0(@typescript-eslint/parser@8.57.0(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3))(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1))
       eslint-plugin-jsx-a11y: 6.10.2(eslint@9.39.4(jiti@2.6.1))
       eslint-plugin-react: 7.37.5(eslint@9.39.4(jiti@2.6.1))
       eslint-plugin-react-hooks: 7.0.1(eslint@9.39.4(jiti@2.6.1))
@@ -13798,21 +13847,22 @@ snapshots:
       tinyglobby: 0.2.15
       unrs-resolver: 1.11.1
     optionalDependencies:
-      eslint-plugin-import: 2.32.0(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1))
+      eslint-plugin-import: 2.32.0(@typescript-eslint/parser@8.57.0(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3))(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1))
     transitivePeerDependencies:
       - supports-color
 
-  eslint-module-utils@2.12.1(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1)):
+  eslint-module-utils@2.12.1(@typescript-eslint/parser@8.57.0(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1)):
     dependencies:
       debug: 3.2.7
     optionalDependencies:
+      '@typescript-eslint/parser': 8.57.0(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3)
       eslint: 9.39.4(jiti@2.6.1)
       eslint-import-resolver-node: 0.3.9
       eslint-import-resolver-typescript: 3.10.1(eslint-plugin-import@2.32.0)(eslint@9.39.4(jiti@2.6.1))
     transitivePeerDependencies:
       - supports-color
 
-  eslint-plugin-import@2.32.0(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1)):
+  eslint-plugin-import@2.32.0(@typescript-eslint/parser@8.57.0(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3))(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1)):
     dependencies:
       '@rtsao/scc': 1.1.0
       array-includes: 3.1.9
@@ -13823,7 +13873,7 @@ snapshots:
       doctrine: 2.1.0
       eslint: 9.39.4(jiti@2.6.1)
       eslint-import-resolver-node: 0.3.9
-      eslint-module-utils: 2.12.1(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1))
+      eslint-module-utils: 2.12.1(@typescript-eslint/parser@8.57.0(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.10.1)(eslint@9.39.4(jiti@2.6.1))
       hasown: 2.0.2
       is-core-module: 2.16.1
       is-glob: 4.0.3
@@ -13834,6 +13884,8 @@ snapshots:
       semver: 6.3.1
       string.prototype.trimend: 1.0.9
       tsconfig-paths: 3.15.0
+    optionalDependencies:
+      '@typescript-eslint/parser': 8.57.0(eslint@9.39.4(jiti@2.6.1))(typescript@5.9.3)
     transitivePeerDependencies:
       - eslint-import-resolver-typescript
       - eslint-import-resolver-webpack
@@ -14897,6 +14949,10 @@ snapshots:
 
   html-escaper@2.0.2: {}
 
+  html-parse-stringify@3.0.1:
+    dependencies:
+      void-elements: 3.1.0
+
   html-url-attributes@3.0.1: {}
 
   html-void-elements@3.0.0: {}
@@ -14930,6 +14986,16 @@ snapshots:
 
   husky@9.1.7: {}
 
+  i18next-resources-to-backend@1.2.1:
+    dependencies:
+      '@babel/runtime': 7.29.2
+
+  i18next@26.0.1(typescript@5.9.3):
+    dependencies:
+      '@babel/runtime': 7.29.2
+    optionalDependencies:
+      typescript: 5.9.3
+
   iconv-lite@0.4.24:
     dependencies:
       safer-buffer: 2.1.2
@@ -17462,6 +17528,17 @@ snapshots:
       react: 19.2.3
       scheduler: 0.27.0
 
+  react-i18next@17.0.1(i18next@26.0.1(typescript@5.9.3))(react-dom@19.2.3(react@19.2.3))(react@19.2.3)(typescript@5.9.3):
+    dependencies:
+      '@babel/runtime': 7.29.2
+      html-parse-stringify: 3.0.1
+      i18next: 26.0.1(typescript@5.9.3)
+      react: 19.2.3
+      use-sync-external-store: 1.6.0(react@19.2.3)
+    optionalDependencies:
+      react-dom: 19.2.3(react@19.2.3)
+      typescript: 5.9.3
+
   react-is@16.13.1: {}
 
   react-is@18.3.1: {}
@@ -18942,6 +19019,8 @@ snapshots:
     transitivePeerDependencies:
       - msw
 
+  void-elements@3.1.0: {}
+
   vue-eslint-parser@2.0.3(eslint@4.19.1):
     dependencies:
       debug: 3.2.7