feat: Add cht language support.

add CRLF to LF in Dockerfile.

.gitattributes

@@ -0,0 +1,8 @@
+# Normalize line endings to avoid CRLF issues in Linux containers
+* text=auto
+
+# Shell scripts must be LF for correct shebang parsing
+*.sh text eol=lf
+
+# PowerShell scripts are typically CRLF on Windows
+*.ps1 text eol=crlf

Dockerfile

@@ -6,9 +6,13 @@ ENV PYTHONDONTWRITEBYTECODE=1 \
 WORKDIR /app
 
 RUN apt-get update \
-    && apt-get install -y --no-install-recommends build-essential \
+    && apt-get install -y --no-install-recommends build-essential tzdata \
     && rm -rf /var/lib/apt/lists/*
 
+COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
+RUN sed -i 's/\r$//' /usr/local/bin/docker-entrypoint.sh \
+    && chmod +x /usr/local/bin/docker-entrypoint.sh
+
 COPY requirements.txt ./
 RUN pip install --no-cache-dir -r requirements.txt
 
@@ -17,4 +21,6 @@ COPY frontend ./frontend
 
 EXPOSE 8080
 
+ENTRYPOINT ["/usr/local/bin/docker-entrypoint.sh"]
+
 CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8080"]

README.md

@@ -26,6 +26,22 @@ PlexPlaylistSync 是一个用于同步 Plex 播放列表和本地 `.m3u`/`.m3u8`
 docker compose up --build
 ```
 
+### 配置容器时区
+
+本项目支持通过 `docker-compose.yml` 的环境变量 `TZ` 配置容器运行时区（需要使用有效的 IANA 时区名，例如 `Asia/Shanghai`、`UTC`、`America/New_York`）。
+
+- 临时指定（当前终端会话生效）：
+
+```bash
+TZ=UTC docker compose up --build
+```
+
+- 或在项目根目录创建 `.env`：
+
+```env
+TZ=Asia/Shanghai
+```
+
 - 默认会以 `--reload` 模式启动，监听本地 8080 端口，可在浏览器访问 `http://localhost:8080`。
 - 通过 `./app/config.json` 保存的 Plex 配置信息会在主机和容器间共享，便于调试时保留登录 token 等数据。
 - 如需自定义端口或其他参数，可在 `docker-compose.yml` 中调整。

docker-compose.yml

@@ -11,4 +11,5 @@ services:
       - PYTHONUNBUFFERED=1
       - PYTHONDONTWRITEBYTECODE=1
       - LOG_LEVEL=INFO
+      - TZ=${TZ:-Asia/Tokyo}
     restart: unless-stopped

docker-entrypoint.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env sh
+set -eu
+
+# Configure timezone inside the container if TZ is provided.
+# This avoids relying on host mounts like /etc/localtime, which are awkward on Windows.
+if [ "${TZ:-}" != "" ]; then
+  ZONEINFO="/usr/share/zoneinfo/${TZ}"
+  if [ -e "$ZONEINFO" ]; then
+    ln -snf "$ZONEINFO" /etc/localtime
+    echo "$TZ" > /etc/timezone
+  else
+    echo "[entrypoint] Warning: TZ='$TZ' not found at $ZONEINFO; keeping existing timezone." >&2
+  fi
+fi
+
+exec "$@"

frontend/App.tsx

@@ -15,7 +15,9 @@ import { SYNC_BANNER_PADDING_X, SYNC_BANNER_PADDING_Y, SYNC_BANNER_MIN_WIDTH } f
 import ServerPanel from './components/ServerPanel';
 import StrategySelector from './components/StrategySelector';
 import ConnectionModal from './components/ConnectionModal';
-import { ArrowLeftRight, ShieldCheck, X, Server, ServerOff, Clock, Eye, EyeOff, Type, Code2, Archive } from 'lucide-react';
+import OverflowMarquee from './components/OverflowMarquee';
+import { ArrowLeftRight, ShieldCheck, X, Server, ServerOff, Clock, Eye, EyeOff, Type, Code2, Archive, Languages } from 'lucide-react';
+import { useLanguage } from './LanguageContext';
 
 interface Toast {
   id: number;
@@ -112,6 +114,7 @@ const useStripeAnimation = (syncState: SyncState) => {
 };
 
 const App: React.FC = () => {
+  const { t, language, setLanguage } = useLanguage();
   const [localPlaylists, setLocalPlaylists] = useState<Playlist[]>([]);
   const [cloudPlaylists, setCloudPlaylists] = useState<Playlist[]>([]);
   const [cloudServerInfo, setCloudServerInfo] = useState<PlexServerConnection | undefined>(undefined);
@@ -134,6 +137,7 @@ const App: React.FC = () => {
 
   // Connection Modal State
   const [isConnectionModalOpen, setIsConnectionModalOpen] = useState(false);
+  const [isLangMenuOpen, setIsLangMenuOpen] = useState(false);
 
   // Strategy State
   const [currentStrategy, setCurrentStrategy] = useState<SyncStrategy>(SyncStrategy.LOCAL_OVERWRITE);
@@ -269,13 +273,15 @@ const App: React.FC = () => {
        loadSchedule();
 
        if (settings.mode === ScheduleMode.DISABLED) {
-          addToast("Scheduled tasks disabled.");
+         addToast(t('toasts.scheduleDisabled'));
+       } else if (settings.mode === ScheduleMode.CRON && settings.cronExpression.trim() === '') {
+         addToast(t('toasts.scheduleEmpty'));
        } else {
-          addToast("Scheduled task updated successfully.");
+         addToast(t('toasts.scheduleStarted'));
        }
        return true;
     } else {
-       addToast(result.message || "Failed to update schedule.");
+       addToast(result.message || t('toasts.scheduleFailed'));
        return false;
     }
   };
@@ -285,9 +291,9 @@ const App: React.FC = () => {
     const result = await apiService.saveBackupSettings(settings);
     if (result.status === 'success') {
       setBackupSettings(settings);
-      addToast('Backup settings have been saved.');
+      addToast(t('toasts.backupSaved'));
     } else {
-      addToast(result.message || 'Failed to save backup settings.');
+      addToast(result.message || t('toasts.backupFailed'));
     }
   };
 
@@ -311,7 +317,7 @@ const App: React.FC = () => {
       localAbortRef.current.abort();
       localAbortRef.current = null;
       setLoadingLocal(false);
-      addToast("Local refresh cancelled.");
+      addToast(t('toasts.localRefreshCancelled'));
     }
   };
 
@@ -345,7 +351,7 @@ const App: React.FC = () => {
       cloudAbortRef.current.abort();
       cloudAbortRef.current = null;
       setLoadingCloud(false);
-      addToast("Cloud refresh cancelled.");
+      addToast(t('toasts.cloudRefreshCancelled'));
     }
   };
 
@@ -372,9 +378,9 @@ const App: React.FC = () => {
     setCurrentStrategy(strategy);
     const result = await apiService.updateSyncStrategy(strategy);
     if (result.status === 'success') {
-      addToast(`Selected strategy "${label}" has been saved.`);
+      addToast(t('toasts.strategySaved', { strategy: label }));
     } else {
-      addToast(result.message || 'Failed to save sync strategy.');
+      addToast(result.message || t('toasts.strategySaveFailed'));
     }
   };
 
@@ -383,9 +389,9 @@ const App: React.FC = () => {
     setPathMappingConfig(config);
     const result = await apiService.savePathMapping(config);
     if (result.status === 'success') {
-      addToast('Path mapping rules have been saved.');
+      addToast(t('toasts.mappingSaved'));
     } else {
-      addToast(result.message || 'Failed to save path mapping rules.');
+      addToast(result.message || t('toasts.mappingSaveFailed'));
     }
   };
 
@@ -410,7 +416,7 @@ const App: React.FC = () => {
       }, SYNC_SUCCESS_TOTAL_MS);
     } else {
       setSyncState(SyncState.ERROR);
-      addToast(result.message || 'Sync failed. Please check connection.');
+      addToast(result.message || t('toasts.syncFailed'));
       setTimeout(() => setSyncState(SyncState.IDLE), SYNC_ERROR_RESET_MS);
     }
   };
@@ -457,11 +463,11 @@ const App: React.FC = () => {
                 setSyncState(SyncState.SUCCESS);
                 refreshLocal();
                 refreshCloud();
-                addToast("Background sync completed successfully.");
+               addToast(t('toasts.backgroundSyncSuccess'));
                 setTimeout(() => setSyncState(SyncState.IDLE), SYNC_SUCCESS_TOTAL_MS);
              } else if (status === 'error') {
                 setSyncState(SyncState.ERROR);
-                addToast(`Background sync failed: ${error}`);
+               addToast(t('toasts.backgroundSyncFailed', { error: error || '' }));
                 setTimeout(() => setSyncState(SyncState.IDLE), SYNC_ERROR_RESET_MS);
              }
           } else {
@@ -518,30 +524,22 @@ const App: React.FC = () => {
   const isConnected = cloudServerInfo?.isConnected;
 
   const getScheduleDisplayInfo = () => {
-    const result = { 
+    const result = {
-        label: 'Auto-Sync', 
+      label: t('dashboard.autoSync'),
-        value: 'Not configured', 
+      value: t('schedule.notConfigured'),
-        active: false,
+      active: false,
-        autoWatch: scheduleSettings.autoWatch 
+      autoWatch: scheduleSettings.autoWatch,
     };
 
     if (scheduleSettings.mode === ScheduleMode.DISABLED) {
-      result.label = 'Auto-Sync';
+      result.value = t('common.disabled');
-      result.value = 'Disabled';
       return result;
     }
-    
-    let label = 'Auto-Sync';
-    if (scheduleSettings.mode === ScheduleMode.CRON) label = 'Cron-Sync';
-    else if (scheduleSettings.mode === ScheduleMode.DAILY) label = 'Daily-Sync';
-    else if (scheduleSettings.mode === ScheduleMode.WEEKLY) label = 'Weekly-Sync';
 
-    result.label = label;
+    if (scheduleSettings.mode === ScheduleMode.CRON && scheduleSettings.cronExpression.trim() === '') {
-    
+      result.value = t('dashboard.notSet');
-    if (scheduleSettings.mode === ScheduleMode.CRON && !scheduleSettings.cronExpression) {
-        result.value = 'Not Set';
     } else {
-        result.value = nextRunTime ? `${nextRunTime}` : 'Calculating...';
+      result.value = nextRunTime ? `${nextRunTime}` : t('common.loading');
     }
 
     result.active = true;
@@ -553,39 +551,36 @@ const App: React.FC = () => {
   // Helper: Calculate Path Mapping Info
   const getPathMappingDisplayInfo = (config: PathMappingConfig) => {
     let count = 0;
-    let modeLabel = '';
     let Icon = Type;
-    let label = 'Mapping';
 
     if (config.mode === PathMappingMode.SIMPLE) {
-        modeLabel = 'Simple';
+      count = config.simple.length;
-        label = 'Simple-Mapping';
+      Icon = Type;
-        count = config.simple.length;
-        Icon = Type;
     } else {
-        modeLabel = 'Regex';
+      count =
-        label = 'Regex-Mapping';
+        config.regex.localPre.length +
-        count = config.regex.localPre.length +
+        config.regex.localPost.length +
-                config.regex.localPost.length + 
+        config.regex.remotePre.length +
-                config.regex.remotePre.length + 
+        config.regex.remotePost.length;
-                config.regex.remotePost.length;
+      Icon = Code2;
-        Icon = Code2;
     }
 
     if (count === 0) {
-        return {
+      return {
-            label: 'Mapping',
+        label: t('dashboard.mapping'),
-            value: 'Not Set',
+        value: t('dashboard.notSet'),
-            active: false,
+        active: false,
-            Icon: Icon
+        Icon,
-        };
+      };
     }
 
+    const modeLabel = config.mode === PathMappingMode.SIMPLE ? t('mapping.simple') : t('mapping.regex');
+
     return {
-        label: label,
+      label: t('dashboard.mapping'),
-        value: `${modeLabel} (${count})`,
+      value: `${modeLabel} (${count})`,
-        active: true,
+      active: true,
-        Icon: Icon
+      Icon,
     };
   };
 
@@ -594,16 +589,16 @@ const App: React.FC = () => {
   // Helper: Calculate Backup Info
   const getBackupDisplayInfo = (settings: BackupSettings) => {
     if (!settings.enabled) {
-        return {
+      return {
-            label: 'Backups',
+        label: t('dashboard.backup'),
-            value: 'Disabled',
+        value: t('common.disabled'),
-            active: false
+        active: false,
-        };
+      };
     }
     return {
-        label: 'Backups',
+      label: t('dashboard.backup'),
-        value: `Keep ${settings.retentionCount}`,
+      value: t('dashboard.keep', { count: settings.retentionCount }),
-        active: true
+      active: true,
     };
   };
 
@@ -691,7 +686,9 @@ const App: React.FC = () => {
                          <span className={`text-[9px] font-bold uppercase tracking-widest transition-colors ${pathMappingInfo.active ? 'text-plex-orange' : 'text-gray-500 group-hover/item:text-gray-400'}`}>{pathMappingInfo.label}</span>
                          <div className={`flex items-center gap-1.5 text-xs font-medium ${pathMappingInfo.active ? 'text-blue-400' : 'text-gray-600'}`}>
                             <pathMappingInfo.Icon size={12} strokeWidth={2.5} className="flex-shrink-0" />
-                            <span className="truncate">{pathMappingInfo.value === 'Not Set' ? 'None' : pathMappingInfo.value}</span>
+                              <OverflowMarquee>
+                                {pathMappingInfo.active ? pathMappingInfo.value : t('common.none')}
+                              </OverflowMarquee>
                          </div>
                       </div>
 
@@ -700,7 +697,9 @@ const App: React.FC = () => {
                          <span className={`text-[9px] font-bold uppercase tracking-widest transition-colors ${backupInfo.active ? 'text-plex-orange' : 'text-gray-500 group-hover/item:text-gray-400'}`}>{backupInfo.label}</span>
                          <div className={`flex items-center gap-1.5 text-xs font-medium ${backupInfo.active ? 'text-indigo-400' : 'text-gray-600'}`}>
                             <Archive size={12} strokeWidth={2.5} className="flex-shrink-0" />
-                            <span className="truncate">{backupInfo.active ? backupInfo.value.replace('Keep ', 'Retain: ') : 'Disabled'}</span>
+                           <OverflowMarquee>
+                             {backupInfo.active ? t('dashboard.retain', { count: backupSettings.retentionCount }) : backupInfo.value}
+                           </OverflowMarquee>
                          </div>
                       </div>
 
@@ -711,19 +710,63 @@ const App: React.FC = () => {
                             {/* Watch Indicator Badge */}
                             <div 
                                 className={`flex items-center gap-1 px-1 rounded-[2px] transition-colors ${scheduleInfo.autoWatch ? 'text-plex-orange bg-plex-orange/10' : 'text-gray-700 bg-gray-800'}`}
-                                title={scheduleInfo.autoWatch ? "Watch Mode: Active" : "Watch Mode: Disabled"}
+                                title={scheduleInfo.autoWatch ? t('dashboard.watchModeActive') : t('dashboard.watchModeDisabled')}
                             >
                                 {scheduleInfo.autoWatch ? <Eye size={9} /> : <EyeOff size={9} />}
-                                <span className="text-[8px] font-bold uppercase">Watch</span>
+                                <span className="text-[8px] font-bold uppercase">{t('dashboard.watch')}</span>
                             </div>
                          </div>
                          <div className={`flex items-center gap-1.5 text-xs font-medium mt-0.5 ${scheduleInfo.active ? 'text-green-400' : 'text-gray-600'}`}>
                             <Clock size={12} strokeWidth={2.5} className="flex-shrink-0" />
-                            <span className="truncate">{scheduleInfo.active ? scheduleInfo.value : 'Disabled'}</span>
+                           <OverflowMarquee>
+                            {scheduleInfo.active ? scheduleInfo.value : t('common.disabled')}
+                           </OverflowMarquee>
                          </div>
                       </div>
                   </div>
 
+                  {/* Language Switcher */}
+                  <div className="relative">
+                    <button
+                      onClick={() => setIsLangMenuOpen(!isLangMenuOpen)}
+                      className="flex items-center justify-center w-9 h-9 rounded-full border border-gray-700 bg-gray-800/50 text-gray-400 hover:text-white hover:bg-gray-700 transition-all"
+                      title={t('common.switchLanguage')}
+                    >
+                      <Languages size={18} />
+                    </button>
+                    {isLangMenuOpen && (
+                      <>
+                        <div className="fixed inset-0 z-40" onClick={() => setIsLangMenuOpen(false)}></div>
+                        <div className="absolute right-0 top-full mt-2 w-32 bg-gray-800 border border-gray-700 rounded-lg shadow-xl z-50 overflow-hidden">
+                          <button 
+                            onClick={() => { setLanguage('en'); setIsLangMenuOpen(false); }}
+                            className={`w-full px-4 py-2 text-sm text-left hover:bg-gray-700 transition-colors ${language === 'en' ? 'text-plex-orange font-bold' : 'text-gray-300'}`}
+                          >
+                            English
+                          </button>
+                          <button 
+                            onClick={() => { setLanguage('es'); setIsLangMenuOpen(false); }}
+                            className={`w-full px-4 py-2 text-sm text-left hover:bg-gray-700 transition-colors ${language === 'es' ? 'text-plex-orange font-bold' : 'text-gray-300'}`}
+                          >
+                            Español
+                          </button>
+                          <button 
+                            onClick={() => { setLanguage('chs'); setIsLangMenuOpen(false); }}
+                            className={`w-full px-4 py-2 text-sm text-left hover:bg-gray-700 transition-colors ${language === 'chs' ? 'text-plex-orange font-bold' : 'text-gray-300'}`}
+                          >
+                            简体中文
+                          </button>
+                          <button 
+                            onClick={() => { setLanguage('cht'); setIsLangMenuOpen(false); }}
+                            className={`w-full px-4 py-2 text-sm text-left hover:bg-gray-700 transition-colors ${language === 'cht' ? 'text-plex-orange font-bold' : 'text-gray-300'}`}
+                          >
+                            繁體中文
+                          </button>
+                        </div>
+                      </>
+                    )}
+                  </div>
+
                   {/* Connection Status Button */}
                   <button 
                     onClick={() => setIsConnectionModalOpen(true)}
@@ -732,7 +775,7 @@ const App: React.FC = () => {
                         ? "bg-green-500/10 border-green-500/50 text-green-400 hover:bg-green-500/20 hover:shadow-green-500/20"
                         : "bg-red-500/10 border-red-500/50 text-red-400 hover:bg-red-500/20 hover:shadow-red-500/20"
                       }`}
-                    title={isConnected ? "Connected to Plex" : "Disconnected"}
+                    title={isConnected ? t('dashboard.connected') : t('dashboard.disconnected')}
                   >
                     {isConnected ? <Server size={18} /> : <ServerOff size={18} />}
                   </button>
@@ -749,7 +792,7 @@ const App: React.FC = () => {
                  }}
                >
                   <h1 className={`text-xl md:text-2xl font-black tracking-[0.2em] uppercase whitespace-nowrap transition-colors duration-300 ${syncState === SyncState.SUCCESS ? 'text-[#22c55e]' : 'text-[#F59E0B]'}`}>
-                    {syncState === SyncState.SYNCING ? 'SYNCHRONIZING' : 'SYNC COMPLETE'}
+                    {syncState === SyncState.SYNCING ? t('dashboard.synchronizing') : t('dashboard.syncComplete')}
                   </h1>
                </div>
             </div>
@@ -834,7 +877,7 @@ const App: React.FC = () => {
       
       {/* Footer */}
       <footer className="flex-none py-4 text-center text-xs text-gray-600 border-t border-white/5 bg-gray-900/50 backdrop-blur">
-        <p>&copy; {new Date().getFullYear()} PlexSync Manager. Connected to Docker backend.</p>
+        <p>{t('app.footer', { year: new Date().getFullYear() })}</p>
       </footer>
 
       {/* Modals */}

frontend/LanguageContext.tsx

@@ -0,0 +1,63 @@
+import React, { createContext, useContext, useEffect, useState, ReactNode } from 'react';
+import { translations, Language } from './translations';
+
+interface LanguageContextProps {
+  language: Language;
+  setLanguage: (lang: Language) => void;
+  t: (path: string, params?: Record<string, string | number>) => string;
+}
+
+const LanguageContext = createContext<LanguageContextProps | undefined>(undefined);
+
+export const LanguageProvider: React.FC<{ children: ReactNode }> = ({ children }) => {
+  const [language, setLanguageState] = useState<Language>('en');
+
+  useEffect(() => {
+    const savedLang = localStorage.getItem('plexsync-language') as Language;
+    if (savedLang && translations[savedLang]) {
+      setLanguageState(savedLang);
+    }
+  }, []);
+
+  const setLanguage = (lang: Language) => {
+    setLanguageState(lang);
+    localStorage.setItem('plexsync-language', lang);
+  };
+
+  const t = (path: string, params?: Record<string, string | number>): string => {
+    const keys = path.split('.');
+    let current: any = translations[language];
+
+    for (const key of keys) {
+      if (current[key] === undefined) {
+        console.warn(`Missing translation for key: ${path} in language: ${language}`);
+        return path;
+      }
+      current = current[key];
+    }
+
+    let text = current as string;
+
+    if (params) {
+      Object.entries(params).forEach(([key, value]) => {
+        text = text.replace(`{${key}}`, String(value));
+      });
+    }
+
+    return text;
+  };
+
+  return (
+    <LanguageContext.Provider value={{ language, setLanguage, t }}>
+      {children}
+    </LanguageContext.Provider>
+  );
+};
+
+export const useLanguage = () => {
+  const context = useContext(LanguageContext);
+  if (!context) {
+    throw new Error('useLanguage must be used within a LanguageProvider');
+  }
+  return context;
+};

frontend/components/ConnectionModal.tsx

@@ -3,6 +3,7 @@ import React, { useState, useEffect, useRef } from 'react';
 import { PlexConnectionSettings, PlexServerConnection, PlexLibrary } from '../types';
 import { apiService } from '../services/api';
 import { X, Server, Lock, User, Key, Globe, Eye, EyeOff, CheckCircle, Library, ChevronDown, ChevronRight, Settings, Loader2 } from 'lucide-react';
+import { useLanguage } from '../LanguageContext';
 
 interface ConnectionModalProps {
   isOpen: boolean;
@@ -13,6 +14,7 @@ interface ConnectionModalProps {
 }
 
 const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onConnectSuccess, onShowMessage, initialSettings }) => {
+  const { t } = useLanguage();
   const [formData, setFormData] = useState<PlexConnectionSettings>({
     protocol: 'http',
     address: '',
@@ -90,9 +92,9 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
        onConnectSuccess(updatedInfo);
        const saveResult = await apiService.updateLibrary(lib.title);
        if (saveResult.status !== 'success') {
-         onShowMessage(saveResult.message || 'Failed to save library selection');
+         onShowMessage(saveResult.message || t('toasts.librarySaveFailed'));
        } else {
-         onShowMessage(`Library switched to ${lib.title}`);
+         onShowMessage(t('toasts.librarySwitched', { library: lib.title }));
        }
     }
   };
@@ -112,7 +114,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
         abortControllerRef.current.abort();
         abortControllerRef.current = null;
         setIsConnecting(false);
-        setError("Connection cancelled by user.");
+        setError(t('toasts.connectionCancelled'));
       }
       return;
     }
@@ -141,7 +143,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
 
       const info = result.data.serverInfo;
       setConnectedServerInfo(info);
-      onShowMessage(`Successfully connected to ${info.name || 'Plex Server'}`);
+      onShowMessage(t('toasts.connectedTo', { name: info.name || 'Plex Server' }));
 
       const libs = info.libraries || [];
       const musicLibraries = libs.filter((lib) => lib.type === 'artist').sort((a, b) => a.title.localeCompare(b.title));
@@ -157,13 +159,13 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
           });
           const saveResult = await apiService.updateLibrary(defaultLib.title);
           if (saveResult.status !== 'success') {
-            setError(saveResult.message || 'Failed to save library selection');
+            setError(saveResult.message || t('toasts.librarySaveFailed'));
           }
       } else {
           onConnectSuccess(info);
       }
     } else {
-      setError(result.message || "Connection failed");
+      setError(result.message || t('server.connectionFailed'));
     }
   };
 
@@ -183,7 +185,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
         <div className="px-6 py-4 bg-gray-800 border-b border-gray-700 flex items-center justify-between flex-none">
           <h3 className="text-lg font-semibold text-white flex items-center gap-2">
             <Server size={18} className={isConnected ? "text-green-400" : "text-plex-orange"} />
-            {isConnected ? 'Server Connected' : 'Connect Plex Server'}
+            {isConnected ? t('connection.titleConnected') : t('connection.titleConnect')}
           </h3>
           <button onClick={onClose} className="text-gray-400 hover:text-white transition-colors">
             <X size={20} />
@@ -202,7 +204,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
 
             {/* Server Connection */}
             <div className="space-y-3">
-                <label className="text-xs font-semibold text-gray-400 uppercase tracking-wider">Server Details</label>
+              <label className="text-xs font-semibold text-gray-400 uppercase tracking-wider">{t('connection.serverDetails')}</label>
                 <div className="grid grid-cols-4 gap-3">
                 <div className="col-span-1">
                     <select
@@ -226,7 +228,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
                         name="address"
                         required
                         disabled={isConnected || isConnecting}
-                        placeholder="IP Address or Domain"
+                      placeholder={t('connection.address')}
                         value={formData.address}
                         onChange={handleChange}
                         className={`w-full h-10 pl-9 pr-3 bg-gray-800 border border-gray-600 rounded-md text-sm text-white placeholder-gray-500 focus:border-plex-orange focus:outline-none focus:ring-1 focus:ring-plex-orange transition-all ${isConnected ? 'opacity-60 cursor-not-allowed' : ''}`}
@@ -240,7 +242,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
                     type="text" 
                     name="port"
                     disabled={isConnected || isConnecting}
-                    placeholder="Port (e.g. 32400)"
+                  placeholder={t('connection.port')}
                     value={formData.port}
                     onChange={handleChange}
                     className={`w-full h-10 px-3 bg-gray-800 border border-gray-600 rounded-md text-sm text-white placeholder-gray-500 focus:border-plex-orange focus:outline-none focus:ring-1 focus:ring-plex-orange transition-all ${isConnected ? 'opacity-60 cursor-not-allowed' : ''}`}
@@ -252,7 +254,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
 
             {/* Authentication */}
             <div className="space-y-3">
-                <label className="text-xs font-semibold text-gray-400 uppercase tracking-wider">Authentication</label>
+              <label className="text-xs font-semibold text-gray-400 uppercase tracking-wider">{t('connection.authentication')}</label>
                 
                 {/* Token */}
                 <div className="relative">
@@ -263,7 +265,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
                     type="text" 
                     name="token"
                     disabled={isConnected || isConnecting}
-                    placeholder="X-Plex-Token (Optional)"
+                  placeholder={t('connection.token')}
                     value={formData.token}
                     onChange={handleChange}
                     className={`w-full h-10 pl-9 pr-3 bg-gray-800 border border-gray-600 rounded-md text-sm text-white placeholder-gray-500 focus:border-plex-orange focus:outline-none focus:ring-1 focus:ring-plex-orange transition-all font-mono ${isConnected ? 'opacity-60 cursor-not-allowed' : ''}`}
@@ -285,7 +287,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
                             type="text" 
                             name="username"
                             disabled={isTokenProvided || isConnecting}
-                            placeholder="Username / Email"
+                          placeholder={t('connection.username')}
                             value={formData.username}
                             onChange={handleChange}
                             className={`w-full h-10 pl-9 pr-3 rounded-md text-sm transition-all focus:outline-none ${disabledInputClass}`}
@@ -301,7 +303,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
                             type={showPassword ? "text" : "password"} 
                             name="password"
                             disabled={isTokenProvided || isConnecting}
-                            placeholder="Password"
+                          placeholder={t('connection.password')}
                             value={formData.password}
                             onChange={handleChange}
                             className={`w-full h-10 pl-9 pr-10 rounded-md text-sm transition-all focus:outline-none ${disabledInputClass}`}
@@ -329,7 +331,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
                 >
                   <div className="flex items-center gap-2">
                     <Settings size={14} />
-                    <span>Advanced Options</span>
+                    <span>{t('connection.advanced')}</span>
                   </div>
                   {showAdvanced ? <ChevronDown size={14} /> : <ChevronRight size={14} />}
                 </button>
@@ -337,7 +339,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
                 {showAdvanced && (
                   <div className="p-3 bg-gray-900/50 space-y-3 animate-in slide-in-from-top-2">
                     <div>
-                      <label className="text-xs text-gray-500 mb-1 block">Connection Timeout (Seconds)</label>
+                      <label className="text-xs text-gray-500 mb-1 block">{t('connection.timeout')}</label>
                       <input 
                         type="number"
                         min="1"
@@ -366,15 +368,15 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
                     {isConnecting ? (
                       <>
                         <Loader2 size={16} className="animate-spin" />
-                        <span>Connecting... <span className="opacity-75 font-normal ml-1">(Cancel)</span></span>
+                        <span>{t('connection.connecting')} <span className="opacity-75 font-normal ml-1">({t('common.cancel')})</span></span>
                       </>
-                    ) : 'Connect Server'}
+                    ) : t('connection.connectBtn')}
                 </button>
             ) : (
                 <div className="mt-2 p-2 bg-green-500/10 border border-green-500/20 rounded-lg text-center">
                     <p className="text-green-400 text-sm font-semibold flex items-center justify-center gap-2">
                         <CheckCircle size={16} />
-                        Connected Successfully
+                      {t('connection.connectedSuccess')}
                     </p>
                 </div>
             )}
@@ -383,7 +385,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
             {/* Library Selection - Appears after connection */}
             {isConnected && libraries.length > 0 && (
                 <div className="mt-6 pt-5 border-t border-gray-700 animate-in slide-in-from-top-2 fade-in">
-                    <label className="text-xs font-semibold text-gray-400 uppercase tracking-wider block mb-2">Select Library to Sync</label>
+                  <label className="text-xs font-semibold text-gray-400 uppercase tracking-wider block mb-2">{t('connection.selectLibrary')}</label>
                     <div className="relative">
                         <div className="absolute inset-y-0 left-0 pl-3 flex items-center pointer-events-none">
                             <Library size={14} className="text-plex-orange" />
@@ -407,7 +409,7 @@ const ConnectionModal: React.FC<ConnectionModalProps> = ({ isOpen, onClose, onCo
                             onClick={onClose}
                             className="px-6 py-2 bg-gray-700 hover:bg-gray-600 text-white text-sm font-medium rounded-lg transition-colors border border-gray-600 hover:border-gray-500"
                         >
-                            Done
+                          {t('common.done')}
                         </button>
                     </div>
                 </div>

frontend/components/OverflowMarquee.tsx

@@ -0,0 +1,117 @@
+import React, { useEffect, useLayoutEffect, useMemo, useRef, useState } from 'react';
+
+type OverflowMarqueeProps = {
+  children: React.ReactNode;
+  className?: string;
+  textClassName?: string;
+  title?: string;
+  speedPxPerSec?: number;
+  minDurationSec?: number;
+};
+
+type MarqueeMetrics = {
+  isOverflowing: boolean;
+  overflowPx: number;
+  durationSec: number;
+};
+
+const DEFAULT_SPEED_PX_PER_SEC = 24;
+const DEFAULT_MIN_DURATION_SEC = 4;
+
+const OverflowMarquee: React.FC<OverflowMarqueeProps> = ({
+  children,
+  className,
+  textClassName,
+  title,
+  speedPxPerSec = DEFAULT_SPEED_PX_PER_SEC,
+  minDurationSec = DEFAULT_MIN_DURATION_SEC,
+}) => {
+  const containerRef = useRef<HTMLSpanElement>(null);
+  const textRef = useRef<HTMLSpanElement>(null);
+  const [metrics, setMetrics] = useState<MarqueeMetrics>({
+    isOverflowing: false,
+    overflowPx: 0,
+    durationSec: minDurationSec,
+  });
+
+  const fallbackTitle = useMemo(() => {
+    if (title) return title;
+    return typeof children === 'string' ? children : undefined;
+  }, [children, title]);
+
+  const recompute = () => {
+    const container = containerRef.current;
+    const text = textRef.current;
+    if (!container || !text) return;
+
+    // Ensure we measure with current layout.
+    const available = container.clientWidth;
+    const content = text.scrollWidth;
+    const overflowPx = Math.ceil(content - available);
+
+    if (overflowPx > 1) {
+      const durationSec = Math.max(minDurationSec, overflowPx / Math.max(1, speedPxPerSec));
+      setMetrics({ isOverflowing: true, overflowPx, durationSec });
+    } else {
+      // Avoid re-render loops if already not overflowing.
+      setMetrics((prev) => (prev.isOverflowing ? { isOverflowing: false, overflowPx: 0, durationSec: minDurationSec } : prev));
+    }
+  };
+
+  useLayoutEffect(() => {
+    recompute();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [children]);
+
+  useEffect(() => {
+    recompute();
+
+    const container = containerRef.current;
+    const text = textRef.current;
+    if (!container || !text) return;
+
+    const ro = new ResizeObserver(() => recompute());
+    ro.observe(container);
+    ro.observe(text);
+
+    const onResize = () => recompute();
+    window.addEventListener('resize', onResize);
+
+    return () => {
+      ro.disconnect();
+      window.removeEventListener('resize', onResize);
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  const textStyle: React.CSSProperties | undefined = metrics.isOverflowing
+    ? ({
+        ['--marquee-distance' as any]: `${metrics.overflowPx}px`,
+        ['--marquee-duration' as any]: `${metrics.durationSec}s`,
+      } satisfies React.CSSProperties)
+    : undefined;
+
+  return (
+    <span
+      ref={containerRef}
+      className={['overflow-marquee', className].filter(Boolean).join(' ')}
+      title={fallbackTitle}
+    >
+      <span
+        ref={textRef}
+        className={[
+          'overflow-marquee__text',
+          metrics.isOverflowing ? 'overflow-marquee__text--animate' : '',
+          textClassName,
+        ]
+          .filter(Boolean)
+          .join(' ')}
+        style={textStyle}
+      >
+        {children}
+      </span>
+    </span>
+  );
+};
+
+export default OverflowMarquee;

frontend/components/PlaylistCard.tsx

@@ -1,26 +1,31 @@
 import React from 'react';
 import { Playlist } from '../types';
 import { Disc3, Clock } from 'lucide-react';
+import { useLanguage } from '../LanguageContext';
+import OverflowMarquee from './OverflowMarquee';
 
 interface PlaylistCardProps {
   playlist: Playlist;
 }
 
 const PlaylistCard: React.FC<PlaylistCardProps> = ({ playlist }) => {
+  const { t } = useLanguage();
   return (
     <div className="group flex flex-col w-full p-2.5 bg-gray-800/60 rounded-md border border-gray-700/50 hover:bg-gray-700 hover:border-plex-orange/50 transition-all duration-200 cursor-pointer shadow-sm">
       <div className="flex items-center justify-between">
-        <h4 className="text-sm font-medium text-gray-200 truncate flex-1 mr-2 group-hover:text-white transition-colors">
+        <h4 className="text-sm font-medium text-gray-200 flex-1 mr-2 group-hover:text-white transition-colors min-w-0">
-          {playlist.title}
+          <OverflowMarquee>
+            {playlist.title}
+          </OverflowMarquee>
         </h4>
       </div>
       
       <div className="flex items-center mt-1.5 space-x-4 text-xs text-gray-500 group-hover:text-gray-400">
-        <span className="flex items-center" title="Track Count">
+        <span className="flex items-center" title={t('playlist.trackCount')}>
           <Disc3 size={12} className="mr-1.5 opacity-70" />
           {playlist.trackCount}
         </span>
-        <span className="flex items-center" title="Last Updated">
+        <span className="flex items-center" title={t('playlist.lastUpdated')}>
           <Clock size={12} className="mr-1.5 opacity-70" />
           {new Date(playlist.lastUpdated).toLocaleDateString()}
         </span>

frontend/components/ServerPanel.tsx

@@ -3,6 +3,8 @@ import React from 'react';
 import { Playlist, ServerType, PlexServerConnection } from '../types';
 import PlaylistCard from './PlaylistCard';
 import { RefreshCw, Server, Cloud, WifiOff, X } from 'lucide-react';
+import { useLanguage } from '../LanguageContext';
+import OverflowMarquee from './OverflowMarquee';
 
 interface ServerPanelProps {
   type: ServerType;
@@ -14,6 +16,7 @@ interface ServerPanelProps {
 }
 
 const ServerPanel: React.FC<ServerPanelProps> = ({ type, playlists, isLoading, onRefresh, onCancel, serverInfo }) => {
+  const { t } = useLanguage();
   const isLocal = type === ServerType.LOCAL;
   
   let Icon = isLocal ? Server : Cloud;
@@ -28,39 +31,44 @@ const ServerPanel: React.FC<ServerPanelProps> = ({ type, playlists, isLoading, o
   let displaySubtitle: React.ReactNode = null;
 
   if (isLocal) {
-    displayTitle = 'Local Server';
+    displayTitle = t('server.local');
     displaySubtitle = (
       <p className="text-xs text-gray-400 font-medium mt-0.5 md:mt-0 md:ml-0">
-        {playlists.length} Playlists
+        {t('server.playlists', { count: playlists.length })}
       </p>
     );
   } else {
     // Cloud Logic
     if (serverInfo) {
       if (serverInfo.isConnected) {
-        displayTitle = serverInfo.name || 'Cloud Server';
+        displayTitle = serverInfo.name || t('server.cloud');
         displaySubtitle = (
            <div className="flex items-center text-xs text-gray-300 font-medium space-x-1.5 truncate mt-0.5 md:mt-0">
-              <span className="text-plex-orange truncate font-semibold">{serverInfo.libraryName}</span>
+              <span className="text-plex-orange font-semibold min-w-0 max-w-full">
+                <span className="block md:hidden truncate">{serverInfo.libraryName}</span>
+                <OverflowMarquee className="hidden md:inline-block">
+                  {serverInfo.libraryName}
+                </OverflowMarquee>
+              </span>
               <span className="text-gray-600 hidden md:inline">•</span>
               <span className="text-gray-500 font-mono text-[10px] hidden md:inline">{serverInfo.ip}:{serverInfo.port}</span>
            </div>
         );
       } else {
-        displayTitle = 'Not Connected';
+        displayTitle = t('server.notConnected');
         Icon = WifiOff;
         headerColor = 'text-red-400';
         displaySubtitle = (
           <p className="text-xs text-gray-500 font-medium mt-0.5">
-             Connection failed
+             {t('server.connectionFailed')}
           </p>
         );
       }
     } else {
-      displayTitle = 'Cloud Server';
+      displayTitle = t('server.cloud');
       displaySubtitle = (
         <p className="text-xs text-gray-500 font-medium mt-0.5">
-           {isLoading ? 'Connecting...' : 'Waiting...'}
+           {isLoading ? t('server.connecting') : t('server.waiting')}
         </p>
       );
     }
@@ -121,7 +129,7 @@ const ServerPanel: React.FC<ServerPanelProps> = ({ type, playlists, isLoading, o
                : 'text-gray-400 hover:text-white hover:bg-white/10'
              }
           `}
-          title={isLoading ? "Cancel Refresh" : "Refresh Playlists"}
+          title={isLoading ? t('server.cancelRefresh') : t('server.refreshPlaylists')}
         >
           {isLoading ? (
             <div className="relative flex items-center justify-center">
@@ -141,11 +149,11 @@ const ServerPanel: React.FC<ServerPanelProps> = ({ type, playlists, isLoading, o
         {isLoading && playlists.length === 0 ? (
           <div className="flex flex-col items-center justify-center h-full text-gray-500 space-y-3">
             <RefreshCw size={24} className="animate-spin text-plex-orange/50" />
-            <p className="text-xs font-medium tracking-wide uppercase">Syncing...</p>
+            <p className="text-xs font-medium tracking-wide uppercase">{t('server.syncing')}</p>
           </div>
         ) : playlists.length === 0 ? (
           <div className="flex flex-col items-center justify-center h-full text-gray-500">
-            <p className="text-sm">No playlists found.</p>
+            <p className="text-sm">{t('server.noPlaylists')}</p>
           </div>
         ) : (
           <div className="space-y-2.5 md:space-y-3">

frontend/components/StrategySelector.tsx

@@ -23,6 +23,7 @@ import {
   History,
   Eye
 } from 'lucide-react';
+import { useLanguage } from '../LanguageContext';
 
 // Generate a UUID for mapping rules
 const generateUUID = (): string => {
@@ -40,8 +41,8 @@ const generateUUID = (): string => {
 
 interface StrategyOption {
   value: SyncStrategy;
-  label: string;
+  labelKey: string;
-  description: string;
+  descKey: string;
   icon: React.ElementType;
   color: string;
 }
@@ -49,35 +50,35 @@ interface StrategyOption {
 const STRATEGIES: StrategyOption[] = [
   {
     value: SyncStrategy.LOCAL_OVERWRITE,
-    label: 'Local Overwrite',
+    labelKey: 'strategies.localOverwrite.label',
-    description: 'Local playlist completely overwrites Cloud. (No Diff)',
+    descKey: 'strategies.localOverwrite.desc',
     icon: ArrowRightCircle,
     color: 'text-blue-400'
   },
   {
     value: SyncStrategy.CLOUD_OVERWRITE,
-    label: 'Cloud Overwrite',
+    labelKey: 'strategies.cloudOverwrite.label',
-    description: 'Cloud playlist completely overwrites Local. (No Diff)',
+    descKey: 'strategies.cloudOverwrite.desc',
     icon: ArrowLeftCircle,
     color: 'text-green-400'
   },
   {
     value: SyncStrategy.MERGE_LOCAL,
-    label: 'Two-way Merge (Local Priority)',
+    labelKey: 'strategies.mergeLocal.label',
-    description: 'Merge both. Conflicts resolve to Local version.',
+    descKey: 'strategies.mergeLocal.desc',
     icon: GitMerge,
     color: 'text-blue-300'
   },
   {
     value: SyncStrategy.MERGE_CLOUD,
-    label: 'Two-way Merge (Cloud Priority)',
+    labelKey: 'strategies.mergeCloud.label',
-    description: 'Merge both. Conflicts resolve to Cloud version.',
+    descKey: 'strategies.mergeCloud.desc',
     icon: GitMerge,
     color: 'text-green-300'
   }
 ];
 
-const WEEK_DAYS = ['S', 'M', 'T', 'W', 'T', 'F', 'S'];
+const WEEK_DAY_INDEXES = [0, 1, 2, 3, 4, 5, 6];
 
 // Color Theme Variables for Mapping Editors
 const MAPPING_THEME = {
@@ -145,6 +146,7 @@ const MappingGroupEditor: React.FC<MappingGroupEditorProps> = ({
   leftInputClass,
   rightInputClass
 }) => {
+  const { t } = useLanguage();
   
   const handleAdd = () => {
     if (isLocked) return;
@@ -176,7 +178,7 @@ const MappingGroupEditor: React.FC<MappingGroupEditorProps> = ({
            onClick={handleAdd}
            disabled={isLocked}
            className="p-1 rounded bg-gray-700/50 hover:bg-gray-600 text-gray-400 hover:text-white transition-colors"
-           title="Add Rule"
+           title={t('common.add')}
          >
            <Plus size={12} />
          </button>
@@ -185,14 +187,14 @@ const MappingGroupEditor: React.FC<MappingGroupEditorProps> = ({
        <div className="flex-1 space-y-2 overflow-y-auto max-h-32 custom-scrollbar pr-1">
          {rules.length === 0 ? (
            <div className="text-xs text-gray-600 italic text-center py-2 border border-dashed border-gray-700/50 rounded-lg">
-             No rules defined.
+             {t('mapping.noRules')}
            </div>
          ) : (
            rules.map((rule) => (
              <div key={rule.id} className="flex items-center space-x-1 animate-in slide-in-from-left-1 duration-200">
                 <input 
                   type="text" 
-                  placeholder={leftPlaceholder}
+                  placeholder={leftPlaceholder || t('mapping.pattern')}
                   value={rule.search}
                   onChange={(e) => handleUpdate(rule.id, 'search', e.target.value)}
                   className={`flex-1 min-w-0 border rounded px-1.5 py-1 text-xs focus:outline-none transition-colors ${leftInputClass || defaultInputStyle}`}
@@ -200,7 +202,7 @@ const MappingGroupEditor: React.FC<MappingGroupEditorProps> = ({
                 <Link size={12} className="text-gray-600 flex-none opacity-50" />
                 <input 
                   type="text" 
-                  placeholder={rightPlaceholder}
+                  placeholder={rightPlaceholder || t('mapping.replace')}
                   value={rule.replace}
                   onChange={(e) => handleUpdate(rule.id, 'replace', e.target.value)}
                   className={`flex-1 min-w-0 border rounded px-1.5 py-1 text-xs focus:outline-none transition-colors ${rightInputClass || defaultInputStyle}`}
@@ -244,6 +246,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
   syncState,
   onSync
 }) => {
+  const { t } = useLanguage();
   const [isOpen, setIsOpen] = useState(false);
   const dropdownRef = useRef<HTMLDivElement>(null);
 
@@ -321,7 +324,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
 
   const handleSelect = (strategy: StrategyOption) => {
     if (isLocked) return;
-    onSelect(strategy.value, strategy.label);
+    onSelect(strategy.value, t(strategy.labelKey));
   };
 
   // --- Path Mapping Handlers ---
@@ -453,7 +456,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
       <button
         onClick={() => setIsOpen(!isOpen)}
         className="flex items-center justify-center w-12 h-12 rounded-full bg-gray-800/90 border border-gray-600 hover:border-plex-orange text-gray-300 hover:text-white hover:bg-gray-700/80 transition-all shadow-2xl hover:shadow-plex-orange/30 ring-[6px] md:ring-8 ring-gray-900 backdrop-blur-sm active:scale-95"
-        title={`Current Strategy: ${selectedOption.label}`}
+        title={`${t('strategies.title')}: ${t(selectedOption.labelKey)}`}
       >
         <selectedOption.icon size={22} className={selectedOption.color} strokeWidth={2.5} />
         <div className="absolute -bottom-1 -right-1 bg-gray-900 rounded-full border border-gray-600 p-[2px] shadow-sm">
@@ -479,7 +482,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
             
             {/* Section 1: Sync Strategy */}
             <div className="px-4 py-3 bg-black/20 border-b border-white/5 flex-none">
-            <h3 className="text-[10px] font-bold text-gray-500 uppercase tracking-widest mb-2">Sync Strategy</h3>
+            <h3 className="text-[10px] font-bold text-gray-500 uppercase tracking-widest mb-2">{t('strategies.title')}</h3>
             <div className="space-y-1">
                 {STRATEGIES.map((strategy) => (
                 <div
@@ -494,7 +497,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                     <div className="flex items-center space-x-3 overflow-hidden">
                     <strategy.icon size={18} className={strategy.color} />
                     <span className={`text-sm font-medium truncate ${currentStrategy === strategy.value ? 'text-white' : 'text-gray-300 group-hover:text-white'}`}>
-                        {strategy.label}
+                      {t(strategy.labelKey)}
                     </span>
                     </div>
                     
@@ -502,7 +505,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                     <div className="relative group/tooltip">
                         <HelpCircle size={14} className="text-gray-600 hover:text-gray-400 transition-colors" />
                         <div className="absolute right-0 bottom-full mb-2 w-48 p-2.5 bg-gray-900 text-xs text-gray-300 rounded-lg shadow-xl border border-gray-700 pointer-events-none opacity-0 group-hover/tooltip:opacity-100 transition-opacity z-50">
-                            {strategy.description}
+                          {t(strategy.descKey)}
                         </div>
                     </div>
                     
@@ -518,7 +521,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
             {/* Section 1.5: Backup Retention */}
             <div className="px-4 py-3 bg-gray-900/40 border-b border-white/5 flex-none">
               <div className="flex items-center justify-between mb-3">
-                 <h3 className="text-[10px] font-bold text-gray-500 uppercase tracking-widest">Backup Retention</h3>
+                <h3 className="text-[10px] font-bold text-gray-500 uppercase tracking-widest">{t('backup.title')}</h3>
               </div>
               
               <div className="flex flex-col space-y-3">
@@ -528,8 +531,8 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                           <Archive size={16} />
                        </div>
                        <div className="flex flex-col">
-                          <span className="text-sm font-medium text-gray-200">Enable Backups</span>
+                          <span className="text-sm font-medium text-gray-200">{t('backup.enable')}</span>
-                          <span className="text-[10px] text-gray-500">Create a copy before changes</span>
+                          <span className="text-[10px] text-gray-500">{t('backup.enableDesc')}</span>
                        </div>
                     </div>
 
@@ -546,7 +549,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                     <div className="flex items-center justify-between p-2.5 rounded-lg bg-black/20 border border-white/5">
                         <div className="flex items-center space-x-2">
                            <History size={14} className="text-gray-500" />
-                           <span className="text-xs text-gray-400">Max versions to keep:</span>
+                          <span className="text-xs text-gray-400">{t('backup.maxVersions')}</span>
                         </div>
                         <div className="flex items-center space-x-2">
                             <input 
@@ -560,7 +563,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                                }}
                                className="w-16 bg-gray-800 border border-gray-700 text-center text-sm rounded py-1 text-white focus:border-plex-orange focus:outline-none"
                             />
-                            <span className="text-[10px] text-gray-600 italic">{localBackup.retentionCount === 0 ? 'No auto-delete' : 'Oldest deleted automatically'}</span>
+                            <span className="text-[10px] text-gray-600 italic">{localBackup.retentionCount === 0 ? t('backup.noAutoDelete') : t('backup.autoDelete')}</span>
                         </div>
                     </div>
                  </div>
@@ -575,7 +578,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                             : 'bg-transparent border-transparent text-gray-700 cursor-not-allowed'}`}
                     >
                         <RotateCcw size={12} />
-                        <span>Revert</span>
+                        <span>{t('common.revert')}</span>
                     </button>
                     <button
                         onClick={handleSaveBackupClick}
@@ -586,7 +589,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                             : 'bg-gray-800/30 border-gray-800/50 text-gray-600 cursor-not-allowed'}`}
                     >
                         <Save size={12} />
-                        <span>Save</span>
+                        <span>{t('common.save')}</span>
                     </button>
                  </div>
               </div>
@@ -595,14 +598,14 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
             {/* Section 2: Path Mapping (Tabs + Grid) */}
             <div className="p-4 bg-gray-900/40 border-b border-white/5 flex-none">
                 <div className="flex items-center justify-between mb-3">
-                    <h3 className="text-[10px] font-bold text-gray-500 uppercase tracking-widest">Path Mapping</h3>
+                <h3 className="text-[10px] font-bold text-gray-500 uppercase tracking-widest">{t('mapping.title')}</h3>
                 </div>
 
                 {/* Tabs for Path Mapping Mode */}
                 <div className="flex space-x-1 bg-black/30 p-1 rounded-lg mb-4">
                   {[
-                    { id: PathMappingMode.SIMPLE, label: 'Simple Mapping', icon: Type },
+                    { id: PathMappingMode.SIMPLE, label: t('mapping.simple'), icon: Type },
-                    { id: PathMappingMode.REGEX, label: 'Regex Rules', icon: Code2 },
+                    { id: PathMappingMode.REGEX, label: t('mapping.regex'), icon: Code2 },
                   ].map((tab) => (
                     <button
                       key={tab.id}
@@ -613,8 +616,8 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                           : 'text-gray-400 hover:text-gray-200 hover:bg-white/5'
                         }`}
                     >
-                        <tab.icon size={12} />
+                      <tab.icon size={12} />
-                        <span>{tab.label}</span>
+                      <span>{tab.label}</span>
                     </button>
                   ))}
                 </div>
@@ -625,15 +628,15 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                        // Simple Mode: Single Editor
                        <div className="animate-in fade-in duration-200">
                           <MappingGroupEditor 
-                             title="Path Mapping"
+                              title={t('mapping.simpleTitle')}
-                             subtitle="Map Local paths to Cloud paths using simple string matching"
+                              subtitle={t('mapping.simpleSubtitle')}
                              rules={simpleRules}
                              onChange={updateSimpleGroup}
                              isLocked={isLocked}
                              borderColor={MAPPING_THEME.simple.borderColor}
                              bgColor={MAPPING_THEME.simple.bgColor}
-                             leftPlaceholder="Local Path"
+                              leftPlaceholder={t('mapping.localPath')}
-                             rightPlaceholder="Cloud Path"
+                              rightPlaceholder={t('mapping.cloudPath')}
                              leftInputClass={MAPPING_THEME.inputs.local}
                              rightInputClass={MAPPING_THEME.inputs.cloud}
                           />
@@ -643,8 +646,8 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                        <div className="grid grid-cols-1 md:grid-cols-2 gap-4 animate-in fade-in duration-200">
                           {/* Row 1: Pre-Processing */}
                           <MappingGroupEditor 
-                             title="Local Playlist"
+                              title={t('server.local')}
-                             subtitle="Pre-Processing (Before Sync)"
+                              subtitle={t('mapping.regexPre')}
                              rules={regexRules.localPre}
                              onChange={(rules) => updateRegexGroup('localPre', rules)}
                              isLocked={isLocked}
@@ -653,8 +656,8 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                           />
 
                           <MappingGroupEditor 
-                             title="Remote Playlist"
+                              title={t('server.cloud')}
-                             subtitle="Pre-Processing (Before Sync)"
+                              subtitle={t('mapping.regexPre')}
                              rules={regexRules.remotePre}
                              onChange={(rules) => updateRegexGroup('remotePre', rules)}
                              isLocked={isLocked}
@@ -664,8 +667,8 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
 
                           {/* Row 2: Post-Processing */}
                           <MappingGroupEditor 
-                             title="Local Playlist"
+                              title={t('server.local')}
-                             subtitle="Post-Processing (After Sync / Result)"
+                              subtitle={t('mapping.regexPost')}
                              rules={regexRules.localPost}
                              onChange={(rules) => updateRegexGroup('localPost', rules)}
                              isLocked={isLocked}
@@ -674,8 +677,8 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                           />
 
                           <MappingGroupEditor 
-                             title="Remote Playlist"
+                              title={t('server.cloud')}
-                             subtitle="Post-Processing (After Sync / Result)"
+                              subtitle={t('mapping.regexPost')}
                              rules={regexRules.remotePost}
                              onChange={(rules) => updateRegexGroup('remotePost', rules)}
                              isLocked={isLocked}
@@ -696,7 +699,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                             : 'bg-transparent border-transparent text-gray-700 cursor-not-allowed'}`}
                     >
                         <RotateCcw size={12} />
-                        <span>Revert</span>
+                        <span>{t('common.revert')}</span>
                     </button>
                     <button
                         onClick={handleSaveMappingClick}
@@ -707,7 +710,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                             : 'bg-gray-800/30 border-gray-800/50 text-gray-600 cursor-not-allowed'}`}
                     >
                         <Save size={12} />
-                        <span>Save Rules</span>
+                        <span>{t('mapping.saveRules')}</span>
                     </button>
                 </div>
             </div>
@@ -715,15 +718,14 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
             {/* Section 3: Scheduled Tasks */}
             <div className="p-4 bg-gray-900/40 border-b border-white/5 flex-none">
                  <div className="flex items-center justify-between mb-3">
-                    <h3 className="text-[10px] font-bold text-gray-500 uppercase tracking-widest">Scheduled Tasks</h3>
+                  <h3 className="text-[10px] font-bold text-gray-500 uppercase tracking-widest">{t('schedule.title')}</h3>
                  </div>
 
-                 {/* Tabs */}
                  <div className="flex space-x-1 bg-black/30 p-1 rounded-lg mb-4">
-                    {[
+                   {[
-                      { id: ScheduleMode.CRON, label: 'Cron', icon: Repeat },
+                      { id: ScheduleMode.CRON, label: t('schedule.cron'), icon: Repeat },
-                      { id: ScheduleMode.DAILY, label: 'Daily', icon: Clock },
+                      { id: ScheduleMode.DAILY, label: t('schedule.daily'), icon: Clock },
-                      { id: ScheduleMode.WEEKLY, label: 'Weekly', icon: Calendar },
+                      { id: ScheduleMode.WEEKLY, label: t('schedule.weekly'), icon: Calendar },
                     ].map((tab) => (
                       <button
                         key={tab.id}
@@ -746,7 +748,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                       <div className="flex flex-col animate-in fade-in duration-200">
                          {/* Top Row: Label + Switch */}
                          <div className="flex items-center justify-between mb-3 px-1">
-                           <span className="text-xs text-gray-400 font-medium">Enable Cron Schedule</span>
+                           <span className="text-xs text-gray-400 font-medium">{t('schedule.enableCron')}</span>
                            <button 
                                onClick={() => toggleScheduleEnable(ScheduleMode.CRON)}
                                className={`relative inline-flex h-6 w-11 items-center rounded-full transition-colors focus:outline-none focus:ring-2 focus:ring-plex-orange focus:ring-offset-2 focus:ring-offset-gray-900 ${localSchedule.mode === ScheduleMode.CRON ? 'bg-plex-orange' : 'bg-gray-700'}`}
@@ -779,7 +781,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                        <div className="flex flex-col animate-in fade-in duration-200">
                           {/* Top Row: Label + Switch */}
                           <div className="flex items-center justify-between mb-3 px-1">
-                            <span className="text-xs text-gray-400 font-medium">Enable Daily Run</span>
+                            <span className="text-xs text-gray-400 font-medium">{t('schedule.enableDaily')}</span>
                             <button 
                                 onClick={() => toggleScheduleEnable(ScheduleMode.DAILY)}
                                 className={`relative inline-flex h-6 w-11 items-center rounded-full transition-colors focus:outline-none focus:ring-2 focus:ring-plex-orange focus:ring-offset-2 focus:ring-offset-gray-900 ${localSchedule.mode === ScheduleMode.DAILY ? 'bg-plex-orange' : 'bg-gray-700'}`}
@@ -805,7 +807,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                        <div className="flex flex-col animate-in fade-in duration-200">
                           {/* Top Row: Label + Switch */}
                           <div className="flex items-center justify-between mb-3 px-1">
-                            <span className="text-xs text-gray-400 font-medium">Enable Weekly Run</span>
+                            <span className="text-xs text-gray-400 font-medium">{t('schedule.enableWeekly')}</span>
                             <button 
                                 onClick={() => toggleScheduleEnable(ScheduleMode.WEEKLY)}
                                 className={`relative inline-flex h-6 w-11 items-center rounded-full transition-colors focus:outline-none focus:ring-2 focus:ring-plex-orange focus:ring-offset-2 focus:ring-offset-gray-900 ${localSchedule.mode === ScheduleMode.WEEKLY ? 'bg-plex-orange' : 'bg-gray-700'}`}
@@ -816,12 +818,12 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
 
                           {/* Middle Row: Full Width Capsules */}
                           <div className={`grid grid-cols-7 w-full transition-opacity duration-200 mb-3 ${localSchedule.mode !== ScheduleMode.WEEKLY ? 'opacity-50 pointer-events-none' : ''}`}>
-                             {WEEK_DAYS.map((day, index) => {
+                             {WEEK_DAY_INDEXES.map((dayIndex) => {
-                               const isSelected = localSchedule.weeklyDays.includes(index);
+                               const isSelected = localSchedule.weeklyDays.includes(dayIndex);
                                return (
                                  <button
-                                   key={index}
+                                   key={dayIndex}
-                                   onClick={() => toggleWeekDay(index)}
+                                   onClick={() => toggleWeekDay(dayIndex)}
                                    className={`h-9 text-xs font-bold border-y border-l last:border-r border-gray-600/50 transition-colors
                                      first:rounded-l-lg last:rounded-r-lg
                                      ${isSelected 
@@ -830,7 +832,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                                      }
                                    `}
                                  >
-                                   {day}
+                                   {t(`schedule.weekdaysNarrow.${dayIndex}`)}
                                  </button>
                                )
                              })}
@@ -857,8 +859,8 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                              <Eye size={16} />
                         </div>
                         <div className="flex flex-col">
-                             <span className="text-sm font-medium text-gray-200">Watch Local Changes</span>
+                             <span className="text-sm font-medium text-gray-200">{t('schedule.watchLocal')}</span>
-                             <span className="text-[10px] text-gray-500">Auto-sync when local playlist updates</span>
+                             <span className="text-[10px] text-gray-500">{t('schedule.watchDesc')}</span>
                         </div>
                     </div>
                     <button 
@@ -880,7 +882,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                                 : 'bg-transparent border-transparent text-gray-700 cursor-not-allowed'}`}
                         >
                             <RotateCcw size={12} />
-                            <span>Revert</span>
+                            <span>{t('common.revert')}</span>
                         </button>
                         <button
                             onClick={handleSaveScheduleClick}
@@ -891,7 +893,7 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                                 : 'bg-gray-800/30 border-gray-800/50 text-gray-600 cursor-not-allowed'}`}
                         >
                             <Save size={12} />
-                            <span>Save</span>
+                            <span>{t('common.save')}</span>
                         </button>
                     </div>
             </div>
@@ -913,18 +915,18 @@ const StrategySelector: React.FC<StrategySelectorProps> = ({
                 {isSyncing ? (
                     <>
                         <Loader2 size={16} className="animate-spin" />
-                        <span>Sync in Progress...</span>
+                        <span>{t('strategies.syncing')}</span>
                     </>
                 ) : (
                     <>
                         <Zap size={16} fill="currentColor" />
-                        <span>Sync Now</span>
+                        <span>{t('strategies.syncNow')}</span>
                     </>
                 )}
             </button>
             {(isMappingDirty || isBackupDirty) && (
                 <p className="text-[10px] text-plex-orange text-center mt-2">
-                    Please save pending changes (Backups/Path Mapping) before syncing.
+                    {t('strategies.saveWarning')}
                 </p>
             )}
         </div>

frontend/index.html

@@ -36,6 +36,41 @@
       ::-webkit-scrollbar-thumb:hover {
         background: #6b7280; 
       }
+
+      /* Overflow marquee (auto-scroll when truncated) */
+      .overflow-marquee {
+        display: inline-block;
+        overflow: hidden;
+        white-space: nowrap;
+        max-width: 100%;
+      }
+
+      .overflow-marquee__text {
+        display: inline-block;
+        will-change: transform;
+      }
+
+      .overflow-marquee__text--animate {
+        animation: overflow-marquee-scroll var(--marquee-duration, 6s) linear infinite;
+      }
+
+      @keyframes overflow-marquee-scroll {
+        0%, 12% {
+          transform: translateX(0);
+        }
+        70%, 86% {
+          transform: translateX(calc(var(--marquee-distance, 0px) * -1));
+        }
+        100% {
+          transform: translateX(0);
+        }
+      }
+
+      @media (prefers-reduced-motion: reduce) {
+        .overflow-marquee__text--animate {
+          animation: none;
+        }
+      }
     </style>
   <script type="importmap">
 {

frontend/index.tsx

@@ -1,6 +1,7 @@
 import React from 'react';
 import ReactDOM from 'react-dom/client';
 import App from './App';
+import { LanguageProvider } from './LanguageContext';
 
 const rootElement = document.getElementById('root');
 if (!rootElement) {
@@ -10,6 +11,8 @@ if (!rootElement) {
 const root = ReactDOM.createRoot(rootElement);
 root.render(
   <React.StrictMode>
-    <App />
+    <LanguageProvider>
+      <App />
+    </LanguageProvider>
   </React.StrictMode>
 );

frontend/locales/cht.ts

@@ -0,0 +1,161 @@
+export const cht = {
+  app: {
+    title: 'PlexSync',
+    manager: '管理',
+    footer: '© {year} PMS Playlist Sync。已連線至 Docker 後端。',
+  },
+  common: {
+    save: '儲存',
+    cancel: '取消',
+    revert: '還原',
+    delete: '刪除',
+    done: '完成',
+    loading: '載入中…',
+    refresh: '重新整理',
+    close: '關閉',
+    none: '無',
+    disabled: '已停用',
+    add: '新增',
+    switchLanguage: '切換語言',
+  },
+  server: {
+    local: '本機伺服器',
+    cloud: '雲端伺服器',
+    playlists: '{count} 個播放清單',
+    notConnected: '未連線',
+    connectionFailed: '連線失敗',
+    connecting: '連線中…',
+    waiting: '等待中…',
+    syncing: '同步中…',
+    noPlaylists: '找不到播放清單。',
+    cancelRefresh: '取消重新整理',
+    refreshPlaylists: '重新整理播放清單',
+  },
+  playlist: {
+    trackCount: '曲目數',
+    lastUpdated: '上次更新',
+  },
+  dashboard: {
+    mapping: '路徑對應',
+    backup: '備份',
+    autoSync: '自動同步',
+    watch: '監看',
+    watchModeActive: '監看模式：啟用',
+    watchModeDisabled: '監看模式：停用',
+    notSet: '未設定',
+    retain: '保留：{count}',
+    keep: '保留 {count}',
+    connected: '已連線至 Plex',
+    disconnected: '未連線',
+    synchronizing: 'SYNCHRONIZING',
+    syncComplete: 'SYNC COMPLETE',
+  },
+  strategies: {
+    title: '同步策略',
+    localOverwrite: {
+      label: '本機覆寫',
+      desc: '本機播放清單完全覆寫雲端。（無 Diff）',
+    },
+    cloudOverwrite: {
+      label: '雲端覆寫',
+      desc: '雲端播放清單完全覆寫本機。（無 Diff）',
+    },
+    mergeLocal: {
+      label: '雙向合併（本機優先）',
+      desc: '合併兩端。衝突以本機版本為準。',
+    },
+    mergeCloud: {
+      label: '雙向合併（雲端優先）',
+      desc: '合併兩端。衝突以雲端版本為準。',
+    },
+    syncNow: '立即同步',
+    syncing: '同步進行中…',
+    saveWarning: '同步前請先儲存待處理的變更（備份/路徑對應）。',
+  },
+  mapping: {
+    title: '路徑對應',
+    simple: '簡易對應',
+    regex: 'Regex 規則',
+    simpleTitle: '路徑對應',
+    simpleSubtitle: '使用簡單字串比對將本機路徑對應到雲端路徑',
+    regexPre: '前處理（同步前）',
+    regexPost: '後處理（同步後 / 結果）',
+    localPath: '本機路徑',
+    cloudPath: '雲端路徑',
+    pattern: '模式',
+    replace: '取代',
+    saveRules: '儲存規則',
+    noRules: '尚未定義規則。',
+  },
+  backup: {
+    title: '備份保留',
+    enable: '啟用備份',
+    enableDesc: '變更前建立副本',
+    maxVersions: '保留的最大版本數：',
+    noAutoDelete: '不自動刪除',
+    autoDelete: '自動刪除最舊版本',
+  },
+  schedule: {
+    title: '排程任務',
+    cron: 'Cron',
+    daily: '每日',
+    weekly: '每週',
+    weekdaysNarrow: {
+      0: '日',
+      1: '一',
+      2: '二',
+      3: '三',
+      4: '四',
+      5: '五',
+      6: '六',
+    },
+    enableCron: '啟用 Cron 排程',
+    enableDaily: '啟用每日執行',
+    enableWeekly: '啟用每週執行',
+    watchLocal: '監看本機變更',
+    watchDesc: '本機播放清單更新時自動同步',
+    schedule: '排程',
+    notConfigured: '尚未設定',
+    today: '今天',
+    tomorrow: '明天',
+  },
+  connection: {
+    titleConnected: '伺服器已連線',
+    titleConnect: '連線 Plex 伺服器',
+    serverDetails: '伺服器詳細資訊',
+    authentication: '驗證',
+    protocol: '通訊協定',
+    address: 'IP 位址或網域',
+    port: '連接埠',
+    token: 'X-Plex-Token（選填）',
+    username: '使用者名稱 / 電子郵件',
+    password: '密碼',
+    advanced: '進階選項',
+    timeout: '連線逾時（秒）',
+    connectBtn: '連線伺服器',
+    connecting: '連線中…',
+    connectedSuccess: '連線成功',
+    selectLibrary: '選擇要同步的媒體庫',
+  },
+  toasts: {
+    localRefreshCancelled: '已取消本機重新整理。',
+    cloudRefreshCancelled: '已取消雲端重新整理。',
+    strategySaved: '已儲存選擇的策略「{strategy}」。',
+    strategySaveFailed: '儲存同步策略失敗。',
+    mappingSaved: '已儲存路徑對應規則。',
+    mappingSaveFailed: '儲存路徑對應規則失敗。',
+    backupSaved: '已儲存備份設定。',
+    backupFailed: '儲存備份設定失敗。',
+    scheduleDisabled: '已停用排程任務。',
+    scheduleEmpty: '已停用排程任務（Cron 為空）。',
+    scheduleStarted: '排程任務更新成功。',
+    scheduleFailed: '更新排程失敗。',
+    syncFailed: '同步失敗。請檢查連線。',
+    backgroundSyncSuccess: '背景同步已成功完成。',
+    backgroundSyncFailed: '背景同步失敗：{error}',
+    librarySwitched: '媒體庫已切換為 {library}',
+    connectedTo: '已成功連線到 {name}',
+    connectionCancelled: '使用者已取消連線。',
+    librarySaveFailed: '儲存媒體庫選擇失敗。',
+  },
+};

frontend/locales/en.ts

@@ -0,0 +1,161 @@
+export const en = {
+  app: {
+    title: 'PlexSync',
+    manager: 'Manager',
+    footer: '© {year} PMS Playlist Sync. Connected to Docker backend.',
+  },
+  common: {
+    save: 'Save',
+    cancel: 'Cancel',
+    revert: 'Revert',
+    delete: 'Delete',
+    done: 'Done',
+    loading: 'Loading...',
+    refresh: 'Refresh',
+    close: 'Close',
+    none: 'None',
+    disabled: 'Disabled',
+    add: 'Add',
+    switchLanguage: 'Switch Language',
+  },
+  server: {
+    local: 'Local Server',
+    cloud: 'Cloud Server',
+    playlists: '{count} Playlists',
+    notConnected: 'Not Connected',
+    connectionFailed: 'Connection failed',
+    connecting: 'Connecting...',
+    waiting: 'Waiting...',
+    syncing: 'Syncing...',
+    noPlaylists: 'No playlists found.',
+    cancelRefresh: 'Cancel Refresh',
+    refreshPlaylists: 'Refresh Playlists',
+  },
+  playlist: {
+    trackCount: 'Track Count',
+    lastUpdated: 'Last Updated',
+  },
+  dashboard: {
+    mapping: 'Mapping',
+    backup: 'Backup',
+    autoSync: 'Auto-Sync',
+    watch: 'Watch',
+    watchModeActive: 'Watch Mode: Active',
+    watchModeDisabled: 'Watch Mode: Disabled',
+    notSet: 'Not Set',
+    retain: 'Retain: {count}',
+    keep: 'Keep {count}',
+    connected: 'Connected to Plex',
+    disconnected: 'Disconnected',
+    synchronizing: 'SYNCHRONIZING',
+    syncComplete: 'SYNC COMPLETE',
+  },
+  strategies: {
+    title: 'Sync Strategy',
+    localOverwrite: {
+      label: 'Local Overwrite',
+      desc: 'Local playlist completely overwrites Cloud. (No Diff)',
+    },
+    cloudOverwrite: {
+      label: 'Cloud Overwrite',
+      desc: 'Cloud playlist completely overwrites Local. (No Diff)',
+    },
+    mergeLocal: {
+      label: 'Two-way Merge (Local Priority)',
+      desc: 'Merge both. Conflicts resolve to Local version.',
+    },
+    mergeCloud: {
+      label: 'Two-way Merge (Cloud Priority)',
+      desc: 'Merge both. Conflicts resolve to Cloud version.',
+    },
+    syncNow: 'Sync Now',
+    syncing: 'Sync in Progress...',
+    saveWarning: 'Please save pending changes (Backups/Path Mapping) before syncing.',
+  },
+  mapping: {
+    title: 'Path Mapping',
+    simple: 'Simple Mapping',
+    regex: 'Regex Rules',
+    simpleTitle: 'Path Mapping',
+    simpleSubtitle: 'Map Local paths to Cloud paths using simple string matching',
+    regexPre: 'Pre-Processing (Before Sync)',
+    regexPost: 'Post-Processing (After Sync / Result)',
+    localPath: 'Local Path',
+    cloudPath: 'Cloud Path',
+    pattern: 'Pattern',
+    replace: 'Replace',
+    saveRules: 'Save Rules',
+    noRules: 'No rules defined.',
+  },
+  backup: {
+    title: 'Backup Retention',
+    enable: 'Enable Backups',
+    enableDesc: 'Create a copy before changes',
+    maxVersions: 'Max versions to keep:',
+    noAutoDelete: 'No auto-delete',
+    autoDelete: 'Oldest deleted automatically',
+  },
+  schedule: {
+    title: 'Scheduled Tasks',
+    cron: 'Cron',
+    daily: 'Daily',
+    weekly: 'Weekly',
+    weekdaysNarrow: {
+      0: 'S',
+      1: 'M',
+      2: 'T',
+      3: 'W',
+      4: 'T',
+      5: 'F',
+      6: 'S',
+    },
+    enableCron: 'Enable Cron Schedule',
+    enableDaily: 'Enable Daily Run',
+    enableWeekly: 'Enable Weekly Run',
+    watchLocal: 'Watch Local Changes',
+    watchDesc: 'Auto-sync when local playlist updates',
+    schedule: 'Schedule',
+    notConfigured: 'Not configured',
+    today: 'Today',
+    tomorrow: 'Tomorrow',
+  },
+  connection: {
+    titleConnected: 'Server Connected',
+    titleConnect: 'Connect Plex Server',
+    serverDetails: 'Server Details',
+    authentication: 'Authentication',
+    protocol: 'Protocol',
+    address: 'IP Address or Domain',
+    port: 'Port',
+    token: 'X-Plex-Token (Optional)',
+    username: 'Username / Email',
+    password: 'Password',
+    advanced: 'Advanced Options',
+    timeout: 'Connection Timeout (Seconds)',
+    connectBtn: 'Connect Server',
+    connecting: 'Connecting...',
+    connectedSuccess: 'Connected Successfully',
+    selectLibrary: 'Select Library to Sync',
+  },
+  toasts: {
+    localRefreshCancelled: 'Local refresh cancelled.',
+    cloudRefreshCancelled: 'Cloud refresh cancelled.',
+    strategySaved: 'Selected strategy "{strategy}" has been saved.',
+    strategySaveFailed: 'Failed to save sync strategy.',
+    mappingSaved: 'Path mapping rules have been saved.',
+    mappingSaveFailed: 'Failed to save path mapping rules.',
+    backupSaved: 'Backup settings have been saved.',
+    backupFailed: 'Failed to save backup settings.',
+    scheduleDisabled: 'Scheduled tasks disabled.',
+    scheduleEmpty: 'Scheduled tasks disabled (Empty Cron).',
+    scheduleStarted: 'Scheduled task updated successfully.',
+    scheduleFailed: 'Failed to update schedule.',
+    syncFailed: 'Sync failed. Please check connection.',
+    backgroundSyncSuccess: 'Background sync completed successfully.',
+    backgroundSyncFailed: 'Background sync failed: {error}',
+    librarySwitched: 'Library switched to {library}',
+    connectedTo: 'Successfully connected to {name}',
+    connectionCancelled: 'Connection cancelled by user.',
+    librarySaveFailed: 'Failed to save library selection.',
+  },
+};

frontend/locales/es.ts

@@ -0,0 +1,161 @@
+export const es = {
+  app: {
+    title: 'PlexSync',
+    manager: 'Gestor',
+    footer: '© {year} PMS Playlist Sync. Conectado al backend Docker.',
+  },
+  common: {
+    save: 'Guardar',
+    cancel: 'Cancelar',
+    revert: 'Revertir',
+    delete: 'Eliminar',
+    done: 'Hecho',
+    loading: 'Cargando...',
+    refresh: 'Actualizar',
+    close: 'Cerrar',
+    none: 'Ninguno',
+    disabled: 'Deshabilitado',
+    add: 'Añadir',
+    switchLanguage: 'Cambiar idioma',
+  },
+  server: {
+    local: 'Servidor Local',
+    cloud: 'Servidor Nube',
+    playlists: '{count} Listas',
+    notConnected: 'No Conectado',
+    connectionFailed: 'Conexión fallida',
+    connecting: 'Conectando...',
+    waiting: 'Esperando...',
+    syncing: 'Sincronizando...',
+    noPlaylists: 'No se encontraron listas.',
+    cancelRefresh: 'Cancelar',
+    refreshPlaylists: 'Actualizar Listas',
+  },
+  playlist: {
+    trackCount: 'Pistas',
+    lastUpdated: 'Actualizado',
+  },
+  dashboard: {
+    mapping: 'Mapeo',
+    backup: 'Respaldo',
+    autoSync: 'Auto-Sync',
+    watch: 'Vigilar',
+    watchModeActive: 'Modo Vigía: Activo',
+    watchModeDisabled: 'Modo Vigía: Desactivado',
+    notSet: 'No Def.',
+    retain: 'Retener: {count}',
+    keep: 'Guardar {count}',
+    connected: 'Conectado a Plex',
+    disconnected: 'Desconectado',
+    synchronizing: 'SINCRONIZANDO',
+    syncComplete: 'SINCRONIZACIÓN COMPLETA',
+  },
+  strategies: {
+    title: 'Estrategia de Sync',
+    localOverwrite: {
+      label: 'Sobreescribir Local',
+      desc: 'La lista local sobreescribe la nube. (Sin Diff)',
+    },
+    cloudOverwrite: {
+      label: 'Sobreescribir Nube',
+      desc: 'La lista de la nube sobreescribe la local. (Sin Diff)',
+    },
+    mergeLocal: {
+      label: 'Fusión (Prioridad Local)',
+      desc: 'Fusionar ambas. Conflictos resueltos a versión Local.',
+    },
+    mergeCloud: {
+      label: 'Fusión (Prioridad Nube)',
+      desc: 'Fusionar ambas. Conflictos resueltos a versión Nube.',
+    },
+    syncNow: 'Sincronizar Ahora',
+    syncing: 'Sincronizando...',
+    saveWarning: 'Guarde los cambios pendientes (Respaldos/Mapeo) antes de sincronizar.',
+  },
+  mapping: {
+    title: 'Mapeo de Rutas',
+    simple: 'Mapeo Simple',
+    regex: 'Reglas Regex',
+    simpleTitle: 'Mapeo de Rutas',
+    simpleSubtitle: 'Mapear rutas locales a la nube usando coincidencia simple',
+    regexPre: 'Pre-Procesamiento (Antes de Sync)',
+    regexPost: 'Post-Procesamiento (Después de Sync)',
+    localPath: 'Ruta Local',
+    cloudPath: 'Ruta Nube',
+    pattern: 'Patrón',
+    replace: 'Reemplazo',
+    saveRules: 'Guardar Reglas',
+    noRules: 'No hay reglas definidas.',
+  },
+  backup: {
+    title: 'Retención de Respaldo',
+    enable: 'Habilitar Respaldos',
+    enableDesc: 'Crear copia antes de cambios',
+    maxVersions: 'Máx versiones a guardar:',
+    noAutoDelete: 'Sin auto-borrado',
+    autoDelete: 'El más antiguo se borra automáticamente',
+  },
+  schedule: {
+    title: 'Tareas Programadas',
+    cron: 'Cron',
+    daily: 'Diario',
+    weekly: 'Semanal',
+    weekdaysNarrow: {
+      0: 'D',
+      1: 'L',
+      2: 'M',
+      3: 'X',
+      4: 'J',
+      5: 'V',
+      6: 'S',
+    },
+    enableCron: 'Habilitar Cron',
+    enableDaily: 'Habilitar Ejecución Diaria',
+    enableWeekly: 'Habilitar Ejecución Semanal',
+    watchLocal: 'Vigilar Cambios Locales',
+    watchDesc: 'Auto-sync cuando la lista local se actualiza',
+    schedule: 'Horario',
+    notConfigured: 'No configurado',
+    today: 'Hoy',
+    tomorrow: 'Mañana',
+  },
+  connection: {
+    titleConnected: 'Servidor Conectado',
+    titleConnect: 'Conectar Servidor Plex',
+    serverDetails: 'Detalles del Servidor',
+    authentication: 'Autenticación',
+    protocol: 'Protocolo',
+    address: 'Dirección IP o Dominio',
+    port: 'Puerto',
+    token: 'X-Plex-Token (Opcional)',
+    username: 'Usuario / Email',
+    password: 'Password',
+    advanced: 'Opciones Avanzadas',
+    timeout: 'Tiempo de espera (Segundos)',
+    connectBtn: 'Conectar Servidor',
+    connecting: 'Conectando...',
+    connectedSuccess: 'Conectado Exitosamente',
+    selectLibrary: 'Seleccionar Librería',
+  },
+  toasts: {
+    localRefreshCancelled: 'Actualización local cancelada.',
+    cloudRefreshCancelled: 'Actualización nube cancelada.',
+    strategySaved: 'Estrategia seleccionada "{strategy}" guardada.',
+    strategySaveFailed: 'Error al guardar estrategia de sync.',
+    mappingSaved: 'Reglas de mapeo guardadas.',
+    mappingSaveFailed: 'Error al guardar reglas de mapeo.',
+    backupSaved: 'Configuración de respaldo guardada.',
+    backupFailed: 'Error al guardar configuración de respaldo.',
+    scheduleDisabled: 'Tareas programadas deshabilitadas.',
+    scheduleEmpty: 'Tareas programadas deshabilitadas (Cron Vacío).',
+    scheduleStarted: 'Tarea programada actualizada exitosamente.',
+    scheduleFailed: 'Error al actualizar horario.',
+    syncFailed: 'Fallo en sync. Revise conexión.',
+    backgroundSyncSuccess: 'Sync en segundo plano completado.',
+    backgroundSyncFailed: 'Sync en segundo plano falló: {error}',
+    librarySwitched: 'Librería cambiada a {library}',
+    connectedTo: 'Conectado exitosamente a {name}',
+    connectionCancelled: 'Conexión cancelada por usuario.',
+    librarySaveFailed: 'Error al guardar selección de librería.',
+  },
+};

frontend/locales/zh.ts

@@ -0,0 +1,161 @@
+export const zh = {
+  app: {
+    title: 'PlexSync',
+    manager: '管理',
+    footer: '© {year} PMS Playlist Sync。已连接到 Docker 后端。',
+  },
+  common: {
+    save: '保存',
+    cancel: '取消',
+    revert: '恢复',
+    delete: '删除',
+    done: '完成',
+    loading: '加载中...',
+    refresh: '刷新',
+    close: '关闭',
+    none: '无',
+    disabled: '已禁用',
+    add: '添加',
+    switchLanguage: '切换语言',
+  },
+  server: {
+    local: '本地服务器',
+    cloud: '云端服务器',
+    playlists: '{count} 个播放列表',
+    notConnected: '未连接',
+    connectionFailed: '连接失败',
+    connecting: '正在连接...',
+    waiting: '等待中...',
+    syncing: '同步中...',
+    noPlaylists: '未找到播放列表。',
+    cancelRefresh: '取消刷新',
+    refreshPlaylists: '刷新播放列表',
+  },
+  playlist: {
+    trackCount: '曲目数',
+    lastUpdated: '最近更新',
+  },
+  dashboard: {
+    mapping: '路径映射',
+    backup: '备份',
+    autoSync: '自动同步',
+    watch: '监听',
+    watchModeActive: '监听模式：启用',
+    watchModeDisabled: '监听模式：禁用',
+    notSet: '未设置',
+    retain: '保留：{count}',
+    keep: '保留 {count}',
+    connected: '已连接 Plex',
+    disconnected: '未连接',
+    synchronizing: 'SYNCHRONIZING',
+    syncComplete: 'SYNC COMPLETE',
+  },
+  strategies: {
+    title: '同步策略',
+    localOverwrite: {
+      label: '本地覆盖',
+      desc: '本地播放列表完全覆盖云端。（无 Diff）',
+    },
+    cloudOverwrite: {
+      label: '云端覆盖',
+      desc: '云端播放列表完全覆盖本地。（无 Diff）',
+    },
+    mergeLocal: {
+      label: '双向合并（本地优先）',
+      desc: '合并两端。冲突以本地版本为准。',
+    },
+    mergeCloud: {
+      label: '双向合并（云端优先）',
+      desc: '合并两端。冲突以云端版本为准。',
+    },
+    syncNow: '立即同步',
+    syncing: '同步进行中...',
+    saveWarning: '同步前请先保存待处理的更改（备份/路径映射）。',
+  },
+  mapping: {
+    title: '路径映射',
+    simple: '简单映射',
+    regex: '正则规则',
+    simpleTitle: '路径映射',
+    simpleSubtitle: '使用简单字符串匹配将本地路径映射到云端路径',
+    regexPre: '预处理（同步前）',
+    regexPost: '后处理（同步后 / 结果）',
+    localPath: '本地路径',
+    cloudPath: '云端路径',
+    pattern: '模式',
+    replace: '替换',
+    saveRules: '保存规则',
+    noRules: '尚未定义规则。',
+  },
+  backup: {
+    title: '备份保留',
+    enable: '启用备份',
+    enableDesc: '在更改前创建副本',
+    maxVersions: '保留的最大版本数：',
+    noAutoDelete: '不自动删除',
+    autoDelete: '自动删除最旧版本',
+  },
+  schedule: {
+    title: '定时任务',
+    cron: 'Cron',
+    daily: '每日',
+    weekly: '每周',
+    weekdaysNarrow: {
+      0: '日',
+      1: '一',
+      2: '二',
+      3: '三',
+      4: '四',
+      5: '五',
+      6: '六',
+    },
+    enableCron: '启用 Cron 计划',
+    enableDaily: '启用每日运行',
+    enableWeekly: '启用每周运行',
+    watchLocal: '监听本地更改',
+    watchDesc: '本地播放列表更新时自动同步',
+    schedule: '计划',
+    notConfigured: '未配置',
+    today: '今天',
+    tomorrow: '明天',
+  },
+  connection: {
+    titleConnected: '服务器已连接',
+    titleConnect: '连接 Plex 服务器',
+    serverDetails: '服务器详情',
+    authentication: '认证',
+    protocol: '协议',
+    address: 'IP 地址或域名',
+    port: '端口',
+    token: 'X-Plex-Token（可选）',
+    username: '用户名 / 邮箱',
+    password: '密码',
+    advanced: '高级选项',
+    timeout: '连接超时（秒）',
+    connectBtn: '连接服务器',
+    connecting: '连接中...',
+    connectedSuccess: '连接成功',
+    selectLibrary: '选择要同步的媒体库',
+  },
+  toasts: {
+    localRefreshCancelled: '本地刷新已取消。',
+    cloudRefreshCancelled: '云端刷新已取消。',
+    strategySaved: '已保存选择的策略“{strategy}”。',
+    strategySaveFailed: '保存同步策略失败。',
+    mappingSaved: '已保存路径映射规则。',
+    mappingSaveFailed: '保存路径映射规则失败。',
+    backupSaved: '已保存备份设置。',
+    backupFailed: '保存备份设置失败。',
+    scheduleDisabled: '已禁用定时任务。',
+    scheduleEmpty: '已禁用定时任务（Cron 为空）。',
+    scheduleStarted: '定时任务更新成功。',
+    scheduleFailed: '更新定时任务失败。',
+    syncFailed: '同步失败。请检查连接。',
+    backgroundSyncSuccess: '后台同步已成功完成。',
+    backgroundSyncFailed: '后台同步失败：{error}',
+    librarySwitched: '媒体库已切换为 {library}',
+    connectedTo: '已成功连接到 {name}',
+    connectionCancelled: '用户已取消连接。',
+    librarySaveFailed: '保存媒体库选择失败。',
+  },
+};

frontend/translations.ts

@@ -0,0 +1,14 @@
+import { en } from './locales/en';
+import { es } from './locales/es';
+import { zh as chs } from './locales/zh';
+import { cht } from './locales/cht';
+
+export const translations = {
+  en,
+  es,
+  chs,
+  cht,
+};
+
+export type Language = keyof typeof translations;
+export type TranslationStructure = typeof en;