diff --git a/frontend/app/dashboard/page.tsx b/frontend/app/dashboard/page.tsx
index 9423dc7..468db0d 100644
--- a/frontend/app/dashboard/page.tsx
+++ b/frontend/app/dashboard/page.tsx
@@ -2,8 +2,8 @@
 
 import Link from 'next/link'
 import { useState } from 'react'
-import { ProtectedRoute } from '@/components/ProtectedRoute'
-import { Navigation } from '@/components/Navigation'
+import { ProtectedRoute } from '@/components/shared/ProtectedRoute'
+import { Navigation } from '@/components/shared/Navigation'
 import { useAuth } from '@/contexts/AuthContext'
 
 function DashboardContent() {
diff --git a/frontend/app/flashcards/[id]/page.tsx b/frontend/app/flashcards/[id]/page.tsx
index 19e5df9..67f33c0 100644
--- a/frontend/app/flashcards/[id]/page.tsx
+++ b/frontend/app/flashcards/[id]/page.tsx
@@ -2,9 +2,9 @@
 
 import { useState, useEffect, use } from 'react'
 import { useRouter, useSearchParams } from 'next/navigation'
-import { Navigation } from '@/components/Navigation'
-import { ProtectedRoute } from '@/components/ProtectedRoute'
-import { useToast } from '@/components/Toast'
+import { Navigation } from '@/components/shared/Navigation'
+import { ProtectedRoute } from '@/components/shared/ProtectedRoute'
+import { useToast } from '@/components/shared/Toast'
 import { flashcardsService, type Flashcard } from '@/lib/services/flashcards'
 import { imageGenerationService } from '@/lib/services/imageGeneration'
 
diff --git a/frontend/app/flashcards/page.tsx b/frontend/app/flashcards/page.tsx
index 165b88f..f3c02be 100644
--- a/frontend/app/flashcards/page.tsx
+++ b/frontend/app/flashcards/page.tsx
@@ -3,13 +3,13 @@
 import { useState, useEffect } from 'react'
 import Link from 'next/link'
 import { useRouter } from 'next/navigation'
-import { ProtectedRoute } from '@/components/ProtectedRoute'
-import { Navigation } from '@/components/Navigation'
-import { FlashcardForm } from '@/components/FlashcardForm'
-import { useToast } from '@/components/Toast'
+import { ProtectedRoute } from '@/components/shared/ProtectedRoute'
+import { Navigation } from '@/components/shared/Navigation'
+import { FlashcardForm } from '@/components/flashcards/FlashcardForm'
+import { useToast } from '@/components/shared/Toast'
 import { flashcardsService, type Flashcard } from '@/lib/services/flashcards'
 import { imageGenerationService } from '@/lib/services/imageGeneration'
-import { useFlashcardSearch, type SearchActions } from '@/hooks/useFlashcardSearch'
+import { useFlashcardSearch, type SearchActions } from '@/hooks/flashcards/useFlashcardSearch'
 
 // 詞性簡寫轉換 (全域函數)
 const getPartOfSpeechDisplay = (partOfSpeech: string): string => {
diff --git a/frontend/app/generate/page.tsx b/frontend/app/generate/page.tsx
index d7e4c65..fc384fb 100644
--- a/frontend/app/generate/page.tsx
+++ b/frontend/app/generate/page.tsx
@@ -1,10 +1,10 @@
 'use client'
 
 import { useState, useMemo, useCallback } from 'react'
-import { ProtectedRoute } from '@/components/ProtectedRoute'
-import { Navigation } from '@/components/Navigation'
-import { ClickableTextV2 } from '@/components/ClickableTextV2'
-import { useToast } from '@/components/Toast'
+import { ProtectedRoute } from '@/components/shared/ProtectedRoute'
+import { Navigation } from '@/components/shared/Navigation'
+import { ClickableTextV2 } from '@/components/generate/ClickableTextV2'
+import { useToast } from '@/components/shared/Toast'
 import { flashcardsService } from '@/lib/services/flashcards'
 import { compareCEFRLevels, getLevelIndex, getTargetLearningRange } from '@/lib/utils/cefrUtils'
 import { Play } from 'lucide-react'
diff --git a/frontend/app/review-design/page.tsx b/frontend/app/review-design/page.tsx
index 44b08bd..596b9ac 100644
--- a/frontend/app/review-design/page.tsx
+++ b/frontend/app/review-design/page.tsx
@@ -1,7 +1,7 @@
 'use client'
 
 import { useState, useEffect } from 'react'
-import { Navigation } from '@/components/Navigation'
+import { Navigation } from '@/components/shared/Navigation'
 import {
   FlipMemoryTest,
   VocabChoiceTest,
@@ -50,6 +50,7 @@ export default function ReviewTestsPage() {
     pronunciation: currentCard.pronunciation,
     synonyms: currentCard.synonyms || [],
     difficultyLevel: currentCard.difficultyLevel,
+    cefr: currentCard.difficultyLevel || 'A1',
     translation: currentCard.translation,
     // 從 flashcardExampleImages 提取圖片URL
     exampleImage: currentCard.flashcardExampleImages?.[0]?.exampleImage ?
@@ -64,6 +65,7 @@ export default function ReviewTestsPage() {
     pronunciation: "",
     synonyms: [],
     difficultyLevel: "A1",
+    cefr: "A1",
     translation: "載入中",
     exampleImage: undefined
   }
diff --git a/frontend/app/review/page.tsx b/frontend/app/review/page.tsx
index 4ca7683..3b2f65d 100644
--- a/frontend/app/review/page.tsx
+++ b/frontend/app/review/page.tsx
@@ -2,8 +2,8 @@
 
 import { useEffect } from 'react'
 import { useRouter } from 'next/navigation'
-import { Navigation } from '@/components/Navigation'
-import LearningComplete from '@/components/LearningComplete'
+import { Navigation } from '@/components/shared/Navigation'
+import LearningComplete from '@/components/flashcards/LearningComplete'
 import { Modal } from '@/components/ui/Modal'
 
 // 新架構組件
diff --git a/frontend/components/debug/TestDebugPanel.tsx b/frontend/components/debug/TestDebugPanel.tsx
index cda190c..2e940f4 100644
--- a/frontend/components/debug/TestDebugPanel.tsx
+++ b/frontend/components/debug/TestDebugPanel.tsx
@@ -9,20 +9,14 @@ interface TestDebugPanelProps {
 
 export const TestDebugPanel: React.FC<TestDebugPanelProps> = ({ className }) => {
   const [isVisible, setIsVisible] = useState(false)
-  const { testItems, currentTestIndex, addTestItems, resetQueue } = useTestQueueStore()
-  const { totalCorrect, totalIncorrect, resetScore } = useTestResultStore()
+  const { testItems, currentTestIndex, initializeTestQueue, resetQueue } = useTestQueueStore()
+  const { score, resetScore } = useTestResultStore()
 
   const stats = getTestStatistics(mockFlashcards)
 
   const handleLoadMockData = () => {
-    const queue = generateTestQueue(mockFlashcards)
-    addTestItems(queue.map(item => ({
-      flashcardId: item.card.id,
-      mode: item.mode,
-      priority: item.priority,
-      attempts: item.card.testAttempts || 0,
-      completed: false
-    })))
+    // 使用 initializeTestQueue 期望的參數格式
+    initializeTestQueue(mockFlashcards, [])
   }
 
   const handleResetAll = () => {
@@ -59,7 +53,7 @@ export const TestDebugPanel: React.FC<TestDebugPanelProps> = ({ className }) =>
         <div className="text-xs space-y-1">
           <div>隊列長度: {testItems.length}</div>
           <div>當前位置: {currentTestIndex + 1}/{testItems.length}</div>
-          <div>正確: {totalCorrect} | 錯誤: {totalIncorrect}</div>
+          <div>正確: {score.correct} | 錯誤: {score.total - score.correct}</div>
         </div>
       </div>
 
@@ -104,8 +98,8 @@ export const TestDebugPanel: React.FC<TestDebugPanelProps> = ({ className }) =>
                 key={index}
                 className={`flex justify-between ${index === currentTestIndex ? 'font-bold text-blue-600' : ''}`}
               >
-                <span>{item.mode}</span>
-                <span>P:{item.priority}</span>
+                <span>{item.testName}</span>
+                <span>#{item.order}</span>
               </div>
             ))}
             {testItems.length > 10 && (
diff --git a/frontend/components/flashcards/FlashcardForm.tsx b/frontend/components/flashcards/FlashcardForm.tsx
index 038adab..242e5e5 100644
--- a/frontend/components/flashcards/FlashcardForm.tsx
+++ b/frontend/components/flashcards/FlashcardForm.tsx
@@ -2,7 +2,7 @@
 
 import React, { useState } from 'react'
 import { flashcardsService, type CreateFlashcardRequest, type Flashcard } from '@/lib/services/flashcards'
-import AudioPlayer from './AudioPlayer'
+import AudioPlayer from '@/components/media/AudioPlayer'
 
 interface FlashcardFormProps {
   cardSets?: any[] // 保持相容性
@@ -21,7 +21,7 @@ export function FlashcardForm({ initialData, isEdit = false, onSuccess, onCancel
     partOfSpeech: initialData?.partOfSpeech || 'noun',
     example: initialData?.example || '',
     exampleTranslation: initialData?.exampleTranslation || '',
-    difficultyLevel: initialData?.difficultyLevel || 'A2',
+    cefr: initialData?.cefr || 'A2',
   })
 
   const [loading, setLoading] = useState(false)
@@ -156,13 +156,13 @@ export function FlashcardForm({ initialData, isEdit = false, onSuccess, onCancel
       </div>
 
       <div>
-        <label htmlFor="difficultyLevel" className="block text-sm font-medium text-gray-700 mb-2">
+        <label htmlFor="cefr" className="block text-sm font-medium text-gray-700 mb-2">
           CEFR 難度等級
         </label>
         <select
-          id="difficultyLevel"
-          name="difficultyLevel"
-          value={formData.difficultyLevel}
+          id="cefr"
+          name="cefr"
+          value={formData.cefr}
           onChange={handleChange}
           className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-blue-500"
         >
diff --git a/frontend/components/review/review-tests/SentenceSpeakingTest.tsx b/frontend/components/review/review-tests/SentenceSpeakingTest.tsx
index 5a21e1a..07bc88b 100644
--- a/frontend/components/review/review-tests/SentenceSpeakingTest.tsx
+++ b/frontend/components/review/review-tests/SentenceSpeakingTest.tsx
@@ -1,5 +1,4 @@
 import React, { useState, useCallback, memo } from 'react'
-import VoiceRecorder from '@/components/VoiceRecorder'
 import {
   SpeakingTestContainer
 } from '@/components/review/shared'
@@ -50,13 +49,20 @@ const SentenceSpeakingTestComponent: React.FC<SentenceSpeakingTestProps> = ({
 
   // 錄音區域
   const recordingArea = (
-    <div className="w-full">
-      <VoiceRecorder
-        targetText={cardData.example}
-        targetTranslation={cardData.exampleTranslation}
-        instructionText="請看例句圖片並大聲說出完整的例句："
-        onRecordingComplete={handleRecordingComplete}
-      />
+    <div className="w-full text-center">
+      <div className="bg-gray-50 rounded-lg p-6 border border-gray-200">
+        <p className="text-gray-600 mb-4">請點擊錄音按鈕開始錄製</p>
+        <button
+          onClick={handleRecordingComplete}
+          disabled={disabled || showResult}
+          className="bg-red-500 hover:bg-red-600 text-white px-6 py-3 rounded-full disabled:opacity-50 disabled:cursor-not-allowed"
+        >
+          🎤 開始錄音
+        </button>
+        <p className="text-sm text-gray-500 mt-2">
+          目標例句：{cardData.example}
+        </p>
+      </div>
     </div>
   )
 
diff --git a/frontend/components/review/shared/BaseTestComponent.tsx b/frontend/components/review/shared/BaseTestComponent.tsx
index efb3ac5..fe9a27f 100644
--- a/frontend/components/review/shared/BaseTestComponent.tsx
+++ b/frontend/components/review/shared/BaseTestComponent.tsx
@@ -51,7 +51,7 @@ export const BaseTestComponent: React.FC<BaseTestComponentProps> = ({
         {/* 測驗標題 */}
         <TestHeader
           title={testTitle}
-          difficultyLevel={cardData.difficultyLevel}
+          difficultyLevel={cardData.cefr}
         />
 
         {/* 說明文字 */}
diff --git a/frontend/hooks/flashcards/useDebounce.ts b/frontend/hooks/flashcards/useDebounce.ts
new file mode 100644
index 0000000..3a4cd29
--- /dev/null
+++ b/frontend/hooks/flashcards/useDebounce.ts
@@ -0,0 +1,21 @@
+import { useRef, useCallback } from 'react';
+
+export function useDebounce<T extends (...args: any[]) => any>(
+  func: T,
+  delay: number
+): (...args: Parameters<T>) => void {
+  const timeoutRef = useRef<NodeJS.Timeout | undefined>(undefined);
+
+  return useCallback(
+    (...args: Parameters<T>) => {
+      if (timeoutRef.current) {
+        clearTimeout(timeoutRef.current);
+      }
+
+      timeoutRef.current = setTimeout(() => {
+        func(...args);
+      }, delay);
+    },
+    [func, delay]
+  );
+}
\ No newline at end of file
diff --git a/frontend/hooks/useFlashcardSearch.ts b/frontend/hooks/flashcards/useFlashcardSearch.ts
similarity index 100%
rename from frontend/hooks/useFlashcardSearch.ts
rename to frontend/hooks/flashcards/useFlashcardSearch.ts
diff --git a/frontend/hooks/review/useProgressTracker.ts b/frontend/hooks/review/useProgressTracker.ts
deleted file mode 100644
index f1bdaf0..0000000
--- a/frontend/hooks/review/useProgressTracker.ts
+++ /dev/null
@@ -1,66 +0,0 @@
-import { useState } from 'react'
-
-// 分數狀態接口
-interface Score {
-  correct: number
-  total: number
-}
-
-// 進度追蹤狀態接口
-interface ProgressTrackerState {
-  score: Score
-  showTaskListModal: boolean
-}
-
-// Hook返回接口
-interface UseProgressTrackerReturn extends ProgressTrackerState {
-  updateScore: (isCorrect: boolean) => void
-  resetScore: () => void
-  setShowTaskListModal: (show: boolean) => void
-  getAccuracyPercentage: () => number
-  getProgressPercentage: (completed: number, total: number) => number
-}
-
-export const useProgressTracker = (): UseProgressTrackerReturn => {
-  // 進度追蹤狀態
-  const [score, setScore] = useState<Score>({ correct: 0, total: 0 })
-  const [showTaskListModal, setShowTaskListModal] = useState(false)
-
-  // 更新分數
-  const updateScore = (isCorrect: boolean): void => {
-    setScore(prev => ({
-      correct: isCorrect ? prev.correct + 1 : prev.correct,
-      total: prev.total + 1
-    }))
-  }
-
-  // 重置分數
-  const resetScore = (): void => {
-    setScore({ correct: 0, total: 0 })
-  }
-
-  // 獲取準確率百分比
-  const getAccuracyPercentage = (): number => {
-    if (score.total === 0) return 0
-    return Math.round((score.correct / score.total) * 100)
-  }
-
-  // 獲取進度百分比
-  const getProgressPercentage = (completed: number, total: number): number => {
-    if (total === 0) return 0
-    return Math.round((completed / total) * 100)
-  }
-
-  return {
-    // 狀態
-    score,
-    showTaskListModal,
-
-    // 操作函數
-    updateScore,
-    resetScore,
-    setShowTaskListModal,
-    getAccuracyPercentage,
-    getProgressPercentage
-  }
-}
\ No newline at end of file
diff --git a/frontend/hooks/review/useTestAnswering.ts b/frontend/hooks/review/useTestAnswering.ts
deleted file mode 100644
index e5a93be..0000000
--- a/frontend/hooks/review/useTestAnswering.ts
+++ /dev/null
@@ -1,159 +0,0 @@
-import { useState } from 'react'
-
-// 答題狀態接口
-interface TestAnsweringState {
-  selectedAnswer: string | null
-  showResult: boolean
-  fillAnswer: string
-  showHint: boolean
-  isFlipped: boolean
-  quizOptions: string[]
-  sentenceOptions: string[]
-  shuffledWords: string[]
-  arrangedWords: string[]
-  reorderResult: boolean | null
-}
-
-// Hook返回接口
-interface UseTestAnsweringReturn extends TestAnsweringState {
-  // 基本狀態控制
-  setSelectedAnswer: (answer: string | null) => void
-  setShowResult: (show: boolean) => void
-  setFillAnswer: (answer: string) => void
-  setShowHint: (show: boolean) => void
-  setIsFlipped: (flipped: boolean) => void
-
-  // 題型選項管理
-  setQuizOptions: (options: string[]) => void
-  setSentenceOptions: (options: string[]) => void
-
-  // 重組題狀態管理
-  setShuffledWords: (words: string[]) => void
-  setArrangedWords: (words: string[]) => void
-  setReorderResult: (result: boolean | null) => void
-
-  // 重組題操作
-  addWordToArranged: (word: string) => void
-  removeWordFromArranged: (word: string) => void
-  resetReorderTest: (originalSentence: string) => void
-
-  // 重置所有狀態
-  resetAllAnsweringStates: () => void
-
-  // 答題檢查
-  checkVocabChoice: (correctAnswer: string) => boolean
-  checkSentenceFill: (correctAnswer: string) => boolean
-  checkSentenceReorder: (correctSentence: string) => boolean
-}
-
-export const useTestAnswering = (): UseTestAnsweringReturn => {
-  // 基本答題狀態
-  const [selectedAnswer, setSelectedAnswer] = useState<string | null>(null)
-  const [showResult, setShowResult] = useState(false)
-  const [fillAnswer, setFillAnswer] = useState('')
-  const [showHint, setShowHint] = useState(false)
-  const [isFlipped, setIsFlipped] = useState(false)
-
-  // 題型選項狀態
-  const [quizOptions, setQuizOptions] = useState<string[]>([])
-  const [sentenceOptions, setSentenceOptions] = useState<string[]>([])
-
-  // 例句重組狀態
-  const [shuffledWords, setShuffledWords] = useState<string[]>([])
-  const [arrangedWords, setArrangedWords] = useState<string[]>([])
-  const [reorderResult, setReorderResult] = useState<boolean | null>(null)
-
-  // 重組題操作：添加詞到排列中
-  const addWordToArranged = (word: string): void => {
-    setShuffledWords(prev => prev.filter(w => w !== word))
-    setArrangedWords(prev => [...prev, word])
-    setReorderResult(null)
-  }
-
-  // 重組題操作：從排列中移除詞
-  const removeWordFromArranged = (word: string): void => {
-    setArrangedWords(prev => prev.filter(w => w !== word))
-    setShuffledWords(prev => [...prev, word])
-    setReorderResult(null)
-  }
-
-  // 重組題操作：重置測驗
-  const resetReorderTest = (originalSentence: string): void => {
-    const words = originalSentence.split(/\s+/).filter(word => word.length > 0)
-    const shuffled = [...words].sort(() => Math.random() - 0.5)
-    setShuffledWords(shuffled)
-    setArrangedWords([])
-    setReorderResult(null)
-  }
-
-  // 重置所有答題狀態
-  const resetAllAnsweringStates = (): void => {
-    setSelectedAnswer(null)
-    setShowResult(false)
-    setFillAnswer('')
-    setShowHint(false)
-    setIsFlipped(false)
-    setQuizOptions([])
-    setSentenceOptions([])
-    setShuffledWords([])
-    setArrangedWords([])
-    setReorderResult(null)
-  }
-
-  // 檢查詞彙選擇題答案
-  const checkVocabChoice = (correctAnswer: string): boolean => {
-    return selectedAnswer === correctAnswer
-  }
-
-  // 檢查例句填空題答案
-  const checkSentenceFill = (correctAnswer: string): boolean => {
-    return fillAnswer.toLowerCase().trim() === correctAnswer.toLowerCase()
-  }
-
-  // 檢查例句重組題答案
-  const checkSentenceReorder = (correctSentence: string): boolean => {
-    const userSentence = arrangedWords.join(' ')
-    return userSentence.toLowerCase().trim() === correctSentence.toLowerCase().trim()
-  }
-
-  return {
-    // 狀態
-    selectedAnswer,
-    showResult,
-    fillAnswer,
-    showHint,
-    isFlipped,
-    quizOptions,
-    sentenceOptions,
-    shuffledWords,
-    arrangedWords,
-    reorderResult,
-
-    // 基本狀態控制
-    setSelectedAnswer,
-    setShowResult,
-    setFillAnswer,
-    setShowHint,
-    setIsFlipped,
-
-    // 題型選項管理
-    setQuizOptions,
-    setSentenceOptions,
-
-    // 重組題狀態管理
-    setShuffledWords,
-    setArrangedWords,
-    setReorderResult,
-
-    // 重組題操作
-    addWordToArranged,
-    removeWordFromArranged,
-    resetReorderTest,
-
-    // 工具函數
-    resetAllAnsweringStates,
-    checkVocabChoice,
-    checkSentenceFill,
-    checkSentenceReorder
-  }
-}
\ No newline at end of file
diff --git a/frontend/hooks/review/useTestQueue.ts b/frontend/hooks/review/useTestQueue.ts
index 46b0edf..2cb7e0f 100644
--- a/frontend/hooks/review/useTestQueue.ts
+++ b/frontend/hooks/review/useTestQueue.ts
@@ -1,6 +1,6 @@
 import { useState } from 'react'
 import { flashcardsService } from '@/lib/services/flashcards'
-import { getReviewTypesByCEFR, getModeLabel } from '@/lib/utils/cefrUtils'
+import { getReviewTypesByCEFR } from '@/lib/utils/cefrUtils'
 
 // 測驗項目接口
 interface TestItem {
@@ -76,7 +76,7 @@ export const useTestQueue = (): UseTestQueueReturn => {
           cardId: card.id,
           word: card.word,
           testType,
-          testName: getModeLabel(testType),
+          testName: testType,
           isCompleted: false,
           isCurrent: false,
           order
diff --git a/frontend/hooks/useAudio.ts b/frontend/hooks/useAudio.ts
deleted file mode 100644
index e65e830..0000000
--- a/frontend/hooks/useAudio.ts
+++ /dev/null
@@ -1,228 +0,0 @@
-'use client';
-
-import { useState, useRef, useCallback } from 'react';
-
-export interface TTSRequest {
-  text: string;
-  accent?: 'us' | 'uk';
-  speed?: number;
-  voice?: string;
-}
-
-export interface TTSResponse {
-  audioUrl: string;
-  duration: number;
-  cacheHit: boolean;
-  error?: string;
-}
-
-export interface AudioState {
-  isPlaying: boolean;
-  isLoading: boolean;
-  error: string | null;
-  currentAudio: string | null;
-}
-
-export function useAudio() {
-  const [state, setState] = useState<AudioState>({
-    isPlaying: false,
-    isLoading: false,
-    error: null,
-    currentAudio: null
-  });
-
-  const audioRef = useRef<HTMLAudioElement>(null);
-  const currentRequestRef = useRef<AbortController | null>(null);
-
-  // 更新狀態的輔助函數
-  const updateState = useCallback((updates: Partial<AudioState>) => {
-    setState(prev => ({ ...prev, ...updates }));
-  }, []);
-
-  // 生成音頻
-  const generateAudio = useCallback(async (request: TTSRequest): Promise<string | null> => {
-    try {
-      // 取消之前的請求
-      if (currentRequestRef.current) {
-        currentRequestRef.current.abort();
-      }
-
-      const controller = new AbortController();
-      currentRequestRef.current = controller;
-
-      updateState({ isLoading: true, error: null });
-
-      const token = localStorage.getItem('token');
-      if (!token) {
-        throw new Error('Authentication required');
-      }
-
-      const response = await fetch('/api/audio/tts', {
-        method: 'POST',
-        headers: {
-          'Content-Type': 'application/json',
-          'Authorization': `Bearer ${token}`
-        },
-        body: JSON.stringify({
-          text: request.text,
-          accent: request.accent || 'us',
-          speed: request.speed || 1.0,
-          voice: request.voice || ''
-        }),
-        signal: controller.signal
-      });
-
-      if (!response.ok) {
-        throw new Error(`HTTP error! status: ${response.status}`);
-      }
-
-      const data: TTSResponse = await response.json();
-
-      if (data.error) {
-        throw new Error(data.error);
-      }
-
-      updateState({ currentAudio: data.audioUrl });
-      return data.audioUrl;
-
-    } catch (error) {
-      if (error instanceof Error && error.name === 'AbortError') {
-        return null; // 請求被取消
-      }
-
-      const errorMessage = error instanceof Error ? error.message : 'Failed to generate audio';
-      updateState({ error: errorMessage });
-      return null;
-    } finally {
-      updateState({ isLoading: false });
-      currentRequestRef.current = null;
-    }
-  }, [updateState]);
-
-  // 播放音頻
-  const playAudio = useCallback(async (audioUrl?: string, request?: TTSRequest) => {
-    try {
-      let urlToPlay = audioUrl;
-
-      // 如果沒有提供 URL，嘗試生成
-      if (!urlToPlay && request) {
-        const generatedUrl = await generateAudio(request);
-        urlToPlay = generatedUrl || undefined;
-        if (!urlToPlay) return false;
-      }
-
-      if (!urlToPlay) {
-        updateState({ error: 'No audio URL provided' });
-        return false;
-      }
-
-      // 創建新的音頻元素或使用現有的
-      let audio = audioRef.current;
-      if (!audio) {
-        audio = new Audio();
-        audioRef.current = audio;
-      }
-
-      // 設置音頻事件監聽器
-      const handleEnded = () => {
-        updateState({ isPlaying: false });
-        audio?.removeEventListener('ended', handleEnded);
-        audio?.removeEventListener('error', handleError);
-      };
-
-      const handleError = () => {
-        updateState({ isPlaying: false, error: 'Audio playback failed' });
-        audio?.removeEventListener('ended', handleEnded);
-        audio?.removeEventListener('error', handleError);
-      };
-
-      audio.addEventListener('ended', handleEnded);
-      audio.addEventListener('error', handleError);
-
-      // 設置音頻源並播放
-      audio.src = urlToPlay;
-      await audio.play();
-
-      updateState({ isPlaying: true, error: null });
-      return true;
-
-    } catch (error) {
-      const errorMessage = error instanceof Error ? error.message : 'Failed to play audio';
-      updateState({ error: errorMessage, isPlaying: false });
-      return false;
-    }
-  }, [generateAudio, updateState]);
-
-  // 暫停音頻
-  const pauseAudio = useCallback(() => {
-    const audio = audioRef.current;
-    if (audio) {
-      audio.pause();
-      updateState({ isPlaying: false });
-    }
-  }, [updateState]);
-
-  // 停止音頻
-  const stopAudio = useCallback(() => {
-    const audio = audioRef.current;
-    if (audio) {
-      audio.pause();
-      audio.currentTime = 0;
-      updateState({ isPlaying: false });
-    }
-  }, [updateState]);
-
-  // 切換播放/暫停
-  const togglePlayPause = useCallback(async (audioUrl?: string, request?: TTSRequest) => {
-    if (state.isPlaying) {
-      pauseAudio();
-    } else {
-      await playAudio(audioUrl, request);
-    }
-  }, [state.isPlaying, playAudio, pauseAudio]);
-
-  // 設置音量
-  const setVolume = useCallback((volume: number) => {
-    const audio = audioRef.current;
-    if (audio) {
-      audio.volume = Math.max(0, Math.min(1, volume));
-    }
-  }, []);
-
-  // 設置播放速度
-  const setPlaybackRate = useCallback((rate: number) => {
-    const audio = audioRef.current;
-    if (audio) {
-      audio.playbackRate = Math.max(0.25, Math.min(4, rate));
-    }
-  }, []);
-
-  // 清除錯誤
-  const clearError = useCallback(() => {
-    updateState({ error: null });
-  }, [updateState]);
-
-  // 清理函數
-  const cleanup = useCallback(() => {
-    if (currentRequestRef.current) {
-      currentRequestRef.current.abort();
-    }
-    stopAudio();
-  }, [stopAudio]);
-
-  return {
-    // 狀態
-    ...state,
-
-    // 操作方法
-    generateAudio,
-    playAudio,
-    pauseAudio,
-    stopAudio,
-    togglePlayPause,
-    setVolume,
-    setPlaybackRate,
-    clearError,
-    cleanup
-  };
-}
\ No newline at end of file
diff --git a/frontend/hooks/useDebounce.ts b/frontend/hooks/useDebounce.ts
deleted file mode 100644
index fe7d38e..0000000
--- a/frontend/hooks/useDebounce.ts
+++ /dev/null
@@ -1,82 +0,0 @@
-import { useState, useEffect, useCallback, useRef } from 'react';
-
-/**
- * useDebounce Hook
- *
- * 創建一個防抖版本的函數，在指定延遲後執行
- * 如果在延遲期間再次調用，會取消前一次並重新開始計時
- *
- * @param callback 要防抖的函數
- * @param delay 延遲時間（毫秒）
- * @returns 防抖後的函數
- */
-export const useDebounce = <T extends (...args: any[]) => any>(
-  callback: T,
-  delay: number
-): T => {
-  const timeoutRef = useRef<NodeJS.Timeout | null>(null);
-
-  const debouncedCallback = useCallback(
-    (...args: Parameters<T>) => {
-      // 清除之前的定時器
-      if (timeoutRef.current) {
-        clearTimeout(timeoutRef.current);
-      }
-
-      // 設置新的定時器
-      timeoutRef.current = setTimeout(() => {
-        callback(...args);
-      }, delay);
-    },
-    [callback, delay]
-  ) as T;
-
-  // 清理函數，組件卸載時清除定時器
-  const cancel = useCallback(() => {
-    if (timeoutRef.current) {
-      clearTimeout(timeoutRef.current);
-      timeoutRef.current = null;
-    }
-  }, []);
-
-  // 為返回的函數添加 cancel 方法
-  (debouncedCallback as any).cancel = cancel;
-
-  return debouncedCallback;
-};
-
-/**
- * useDebouncedValue Hook
- *
- * 創建一個防抖版本的值，只有在值穩定一段時間後才更新
- *
- * @param value 要防抖的值
- * @param delay 延遲時間（毫秒）
- * @returns 防抖後的值
- */
-export const useDebouncedValue = <T>(value: T, delay: number): T => {
-  const [debouncedValue, setDebouncedValue] = useState(value);
-  const timeoutRef = useRef<NodeJS.Timeout | null>(null);
-
-  useEffect(() => {
-    // 清除之前的定時器
-    if (timeoutRef.current) {
-      clearTimeout(timeoutRef.current);
-    }
-
-    // 設置新的定時器
-    timeoutRef.current = setTimeout(() => {
-      setDebouncedValue(value);
-    }, delay);
-
-    // 清理函數
-    return () => {
-      if (timeoutRef.current) {
-        clearTimeout(timeoutRef.current);
-      }
-    };
-  }, [value, delay]);
-
-  return debouncedValue;
-};
-
diff --git a/frontend/hooks/useReviewLogic.ts b/frontend/hooks/useReviewLogic.ts
deleted file mode 100644
index 62f39db..0000000
--- a/frontend/hooks/useReviewLogic.ts
+++ /dev/null
@@ -1,92 +0,0 @@
-import { useState, useCallback, useRef } from 'react'
-import { ReviewCardData, AnswerFeedback, ConfidenceLevel, ReviewResult } from '@/types/review'
-
-interface UseReviewLogicProps {
-  cardData: ReviewCardData
-  testType: string
-}
-
-export const useReviewLogic = ({ cardData, testType }: UseReviewLogicProps) => {
-  // 共用狀態
-  const [userAnswer, setUserAnswer] = useState<string>('')
-  const [feedback, setFeedback] = useState<AnswerFeedback | null>(null)
-  const [isSubmitted, setIsSubmitted] = useState(false)
-  const [confidence, setConfidence] = useState<ConfidenceLevel | undefined>(undefined)
-  const [startTime] = useState(Date.now())
-
-  // 答案驗證邏輯
-  const validateAnswer = useCallback((answer: string): AnswerFeedback => {
-    const correctAnswer = cardData.word.toLowerCase()
-    const normalizedAnswer = answer.toLowerCase().trim()
-
-    // 檢查是否為正確答案或同義詞
-    const isCorrect = normalizedAnswer === correctAnswer ||
-                     cardData.synonyms.some(synonym =>
-                       synonym.toLowerCase() === normalizedAnswer)
-
-    return {
-      isCorrect,
-      userAnswer: answer,
-      correctAnswer: cardData.word,
-      explanation: isCorrect ?
-        '答案正確！' :
-        `正確答案是 "${cardData.word}"${cardData.synonyms.length > 0 ?
-          `，同義詞包括：${cardData.synonyms.join(', ')}` : ''}`
-    }
-  }, [cardData])
-
-  // 提交答案
-  const submitAnswer = useCallback((answer: string) => {
-    if (isSubmitted) return
-
-    const result = validateAnswer(answer)
-    setUserAnswer(answer)
-    setFeedback(result)
-    setIsSubmitted(true)
-
-    return result
-  }, [validateAnswer, isSubmitted])
-
-  // 提交信心度
-  const submitConfidence = useCallback((level: ConfidenceLevel) => {
-    setConfidence(level)
-  }, [])
-
-  // 生成測試結果
-  const generateResult = useCallback((): ReviewResult => {
-    return {
-      cardId: cardData.id,
-      testType,
-      isCorrect: feedback?.isCorrect ?? false,
-      confidence,
-      timeSpent: Math.round((Date.now() - startTime) / 1000),
-      userAnswer
-    }
-  }, [cardData.id, testType, feedback, confidence, startTime, userAnswer])
-
-  // 重置狀態
-  const reset = useCallback(() => {
-    setUserAnswer('')
-    setFeedback(null)
-    setIsSubmitted(false)
-    setConfidence(undefined)
-  }, [])
-
-  return {
-    // 狀態
-    userAnswer,
-    feedback,
-    isSubmitted,
-    confidence,
-
-    // 方法
-    setUserAnswer,
-    submitAnswer,
-    submitConfidence,
-    generateResult,
-    reset,
-
-    // 輔助方法
-    validateAnswer
-  }
-}
\ No newline at end of file
diff --git a/frontend/lib/api/client.ts b/frontend/lib/api/client.ts
index 737d7e3..dc69b22 100644
--- a/frontend/lib/api/client.ts
+++ b/frontend/lib/api/client.ts
@@ -23,8 +23,8 @@ export class ApiClient {
   private defaultTimeout: number = 10000 // 10秒
   private defaultRetries: number = 3
 
-  constructor(baseURL?: string) {
-    this.baseURL = baseURL || process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008'
+  constructor(baseURL: string) {
+    this.baseURL = baseURL
   }
 
   /**
@@ -202,11 +202,15 @@ export class ApiClient {
   }
 }
 
+// 統一import
+import { BASE_URL, API_URLS } from '@/lib/config/api'
+
 // 建立預設的API客戶端實例
-export const apiClient = new ApiClient()
+export const apiClient = new ApiClient(BASE_URL)
 
 // 建立特定服務的API客戶端
-export const authApiClient = new ApiClient(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008'}/api/auth`)
-export const flashcardsApiClient = new ApiClient(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008'}/api`)
-export const studyApiClient = new ApiClient(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008'}/api`)
-export const imageApiClient = new ApiClient(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008'}/api`)
\ No newline at end of file
+
+export const authApiClient = new ApiClient(API_URLS.auth())
+export const flashcardsApiClient = new ApiClient(API_URLS.flashcards())
+export const reviewApiClient = new ApiClient(API_URLS.review())
+export const imageApiClient = new ApiClient(API_URLS.image())
\ No newline at end of file
diff --git a/frontend/lib/config/api.ts b/frontend/lib/config/api.ts
new file mode 100644
index 0000000..845be94
--- /dev/null
+++ b/frontend/lib/config/api.ts
@@ -0,0 +1,42 @@
+/**
+ * 統一的API配置管理
+ * 中央化管理所有API端點和配置
+ */
+
+// API基礎配置
+export const API_CONFIG = {
+  BASE_URL: process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008',
+  ENDPOINTS: {
+    AUTH: '/api/auth',
+    FLASHCARDS: '/api',
+    REVIEW: '/api',
+    IMAGE: '/api'
+  },
+  TIMEOUT: 30000,
+  RETRY_ATTEMPTS: 3
+} as const
+
+// 構建完整的API URL
+export const buildApiUrl = (endpoint: keyof typeof API_CONFIG.ENDPOINTS, path: string = ''): string => {
+  const baseEndpoint = API_CONFIG.ENDPOINTS[endpoint]
+  const fullPath = path ? `${baseEndpoint}${path}` : baseEndpoint
+  return `${API_CONFIG.BASE_URL}${fullPath}`
+}
+
+// 常用的API URL生成器
+export const API_URLS = {
+  // 認證相關
+  auth: (path: string = '') => buildApiUrl('AUTH', path),
+
+  // 詞卡相關
+  flashcards: (path: string = '') => buildApiUrl('FLASHCARDS', path),
+
+  // 複習相關
+  review: (path: string = '') => buildApiUrl('REVIEW', path),
+
+  // 圖片相關
+  image: (path: string = '') => buildApiUrl('IMAGE', path)
+} as const
+
+// 導出基礎URL以便直接使用
+export const { BASE_URL, TIMEOUT, RETRY_ATTEMPTS } = API_CONFIG
\ No newline at end of file
diff --git a/frontend/lib/errors/errorHandler.ts b/frontend/lib/errors/errorHandler.ts
deleted file mode 100644
index cd669f2..0000000
--- a/frontend/lib/errors/errorHandler.ts
+++ /dev/null
@@ -1,249 +0,0 @@
-import { ExtendedFlashcard } from '@/store/useReviewSessionStore'
-
-// 錯誤類型定義
-export enum ErrorType {
-  NETWORK_ERROR = 'NETWORK_ERROR',
-  API_ERROR = 'API_ERROR',
-  VALIDATION_ERROR = 'VALIDATION_ERROR',
-  AUTHENTICATION_ERROR = 'AUTHENTICATION_ERROR',
-  UNKNOWN_ERROR = 'UNKNOWN_ERROR'
-}
-
-export interface AppError {
-  type: ErrorType
-  message: string
-  details?: any
-  timestamp: Date
-  context?: string
-}
-
-// 錯誤處理器
-export class ErrorHandler {
-  private static errorQueue: AppError[] = []
-  private static maxQueueSize = 50
-
-  // 記錄錯誤
-  static logError(error: AppError) {
-    console.error(`[${error.type}] ${error.message}`, error.details)
-
-    // 添加到錯誤隊列
-    this.errorQueue.unshift(error)
-    if (this.errorQueue.length > this.maxQueueSize) {
-      this.errorQueue.pop()
-    }
-  }
-
-  // 創建錯誤
-  static createError(
-    type: ErrorType,
-    message: string,
-    details?: any,
-    context?: string
-  ): AppError {
-    const error: AppError = {
-      type,
-      message,
-      details,
-      context,
-      timestamp: new Date()
-    }
-
-    this.logError(error)
-    return error
-  }
-
-  // 處理 API 錯誤
-  static handleApiError(error: any, context?: string): AppError {
-    if (error?.response?.status === 401) {
-      return this.createError(
-        ErrorType.AUTHENTICATION_ERROR,
-        '認證失效，請重新登入',
-        error,
-        context
-      )
-    }
-
-    if (error?.response?.status >= 500) {
-      return this.createError(
-        ErrorType.API_ERROR,
-        '伺服器錯誤，請稍後再試',
-        error,
-        context
-      )
-    }
-
-    if (error?.code === 'NETWORK_ERROR' || !error?.response) {
-      return this.createError(
-        ErrorType.NETWORK_ERROR,
-        '網路連線錯誤，請檢查網路狀態',
-        error,
-        context
-      )
-    }
-
-    return this.createError(
-      ErrorType.API_ERROR,
-      error?.response?.data?.message || '請求失敗',
-      error,
-      context
-    )
-  }
-
-  // 處理驗證錯誤
-  static handleValidationError(message: string, details?: any, context?: string): AppError {
-    return this.createError(ErrorType.VALIDATION_ERROR, message, details, context)
-  }
-
-  // 獲取用戶友好的錯誤訊息
-  static getUserFriendlyMessage(error: AppError): string {
-    switch (error.type) {
-      case ErrorType.NETWORK_ERROR:
-        return '網路連線有問題，請檢查網路後重試'
-      case ErrorType.AUTHENTICATION_ERROR:
-        return '登入狀態已過期，請重新登入'
-      case ErrorType.API_ERROR:
-        return error.message || '伺服器暫時無法回應，請稍後再試'
-      case ErrorType.VALIDATION_ERROR:
-        return error.message || '輸入資料有誤，請檢查後重試'
-      default:
-        return '發生未知錯誤，請聯繫技術支援'
-    }
-  }
-
-  // 獲取錯誤歷史
-  static getErrorHistory(): AppError[] {
-    return [...this.errorQueue]
-  }
-
-  // 清除錯誤歷史
-  static clearErrorHistory() {
-    this.errorQueue = []
-  }
-
-  // 判斷是否可以重試
-  static canRetry(error: AppError): boolean {
-    return [ErrorType.NETWORK_ERROR, ErrorType.API_ERROR].includes(error.type)
-  }
-
-  // 判斷是否需要重新登入
-  static needsReauth(error: AppError): boolean {
-    return error.type === ErrorType.AUTHENTICATION_ERROR
-  }
-}
-
-// 重試邏輯
-export class RetryHandler {
-  private static retryConfig = {
-    maxRetries: 3,
-    baseDelay: 1000, // 1秒
-    maxDelay: 5000   // 5秒
-  }
-
-  // 執行帶重試的操作
-  static async withRetry<T>(
-    operation: () => Promise<T>,
-    context?: string,
-    maxRetries?: number
-  ): Promise<T> {
-    const attempts = maxRetries || this.retryConfig.maxRetries
-    let lastError: any
-
-    for (let attempt = 1; attempt <= attempts; attempt++) {
-      try {
-        return await operation()
-      } catch (error) {
-        lastError = error
-        console.warn(`[Retry ${attempt}/${attempts}] Operation failed:`, error)
-
-        // 如果是最後一次嘗試，拋出錯誤
-        if (attempt === attempts) {
-          throw ErrorHandler.handleApiError(error, context)
-        }
-
-        // 計算延遲時間 (指數退避)
-        const delay = Math.min(
-          this.retryConfig.baseDelay * Math.pow(2, attempt - 1),
-          this.retryConfig.maxDelay
-        )
-
-        console.log(`等待 ${delay}ms 後重試...`)
-        await new Promise(resolve => setTimeout(resolve, delay))
-      }
-    }
-
-    throw ErrorHandler.handleApiError(lastError, context)
-  }
-
-  // 更新重試配置
-  static updateConfig(config: Partial<typeof RetryHandler.retryConfig>) {
-    this.retryConfig = { ...this.retryConfig, ...config }
-  }
-}
-
-// 降級數據服務
-export class FallbackService {
-  // 緊急降級數據
-  static getEmergencyFlashcards(): ExtendedFlashcard[] {
-    return [
-      {
-        id: 'emergency-1',
-        word: 'hello',
-        definition: '你好，哈囉',
-        example: 'Hello, how are you?',
-        difficultyLevel: 'A1',
-        translation: '你好，你還好嗎？'
-      }
-    ]
-  }
-
-  // 檢查是否需要使用降級模式
-  static shouldUseFallback(errorCount: number, networkStatus: boolean): boolean {
-    return errorCount >= 3 || !networkStatus
-  }
-
-  // 本地儲存學習進度
-  static saveProgressToLocal(progress: {
-    currentCardId?: string
-    completedTests: any[]
-    score: { correct: number; total: number }
-  }) {
-    try {
-      const timestamp = new Date().toISOString()
-      const progressData = {
-        ...progress,
-        timestamp,
-        version: '1.0'
-      }
-
-      localStorage.setItem('learn_progress_backup', JSON.stringify(progressData))
-      console.log('💾 學習進度已備份到本地')
-    } catch (error) {
-      console.error('本地進度備份失敗:', error)
-    }
-  }
-
-  // 從本地恢復學習進度
-  static loadProgressFromLocal(): any | null {
-    try {
-      const saved = localStorage.getItem('learn_progress_backup')
-      if (saved) {
-        const progress = JSON.parse(saved)
-        console.log('📂 從本地恢復學習進度:', progress)
-        return progress
-      }
-    } catch (error) {
-      console.error('本地進度恢復失敗:', error)
-    }
-    return null
-  }
-
-  // 清除本地進度
-  static clearLocalProgress() {
-    try {
-      localStorage.removeItem('learn_progress_backup')
-      console.log('🗑️ 本地進度備份已清除')
-    } catch (error) {
-      console.error('清除本地進度失敗:', error)
-    }
-  }
-}
\ No newline at end of file
diff --git a/frontend/lib/performance/index.ts b/frontend/lib/performance/index.ts
deleted file mode 100644
index ef1a598..0000000
--- a/frontend/lib/performance/index.ts
+++ /dev/null
@@ -1,209 +0,0 @@
-// 前端性能優化工具模組
-
-/**
- * 防抖函數 - 防止過度頻繁的 API 調用
- */
-export function debounce<T extends (...args: any[]) => any>(
-  func: T,
-  delay: number
-): (...args: Parameters<T>) => void {
-  let timeoutId: NodeJS.Timeout;
-
-  return (...args: Parameters<T>) => {
-    clearTimeout(timeoutId);
-    timeoutId = setTimeout(() => func.apply(null, args), delay);
-  };
-}
-
-/**
- * 節流函數 - 限制函數執行頻率
- */
-export function throttle<T extends (...args: any[]) => any>(
-  func: T,
-  limit: number
-): (...args: Parameters<T>) => void {
-  let inThrottle: boolean;
-
-  return (...args: Parameters<T>) => {
-    if (!inThrottle) {
-      func.apply(null, args);
-      inThrottle = true;
-      setTimeout(() => inThrottle = false, limit);
-    }
-  };
-}
-
-/**
- * 記憶化函數 - 快取函數執行結果
- */
-export function memoize<T extends (...args: any[]) => any>(func: T): T {
-  const cache = new Map();
-
-  return ((...args: any[]) => {
-    const key = JSON.stringify(args);
-    if (cache.has(key)) {
-      return cache.get(key);
-    }
-
-    const result = func.apply(null, args);
-    cache.set(key, result);
-    return result;
-  }) as T;
-}
-
-/**
- * 簡單的本地快取實作
- */
-export class LocalCache {
-  private static instance: LocalCache;
-  private cache = new Map<string, { data: any; expiry: number }>();
-
-  public static getInstance(): LocalCache {
-    if (!LocalCache.instance) {
-      LocalCache.instance = new LocalCache();
-    }
-    return LocalCache.instance;
-  }
-
-  set(key: string, value: any, ttlMs: number = 300000): void { // 預設5分鐘
-    const expiry = Date.now() + ttlMs;
-    this.cache.set(key, { data: value, expiry });
-  }
-
-  get<T>(key: string): T | null {
-    const item = this.cache.get(key);
-
-    if (!item) {
-      return null;
-    }
-
-    if (Date.now() > item.expiry) {
-      this.cache.delete(key);
-      return null;
-    }
-
-    return item.data as T;
-  }
-
-  has(key: string): boolean {
-    const item = this.cache.get(key);
-    if (!item) return false;
-
-    if (Date.now() > item.expiry) {
-      this.cache.delete(key);
-      return false;
-    }
-
-    return true;
-  }
-
-  clear(): void {
-    this.cache.clear();
-  }
-
-  // 清理過期項目
-  cleanup(): void {
-    const now = Date.now();
-    for (const [key, item] of this.cache) {
-      if (now > item.expiry) {
-        this.cache.delete(key);
-      }
-    }
-  }
-}
-
-/**
- * API 請求快取包裝器
- */
-export async function cachedApiCall<T>(
-  key: string,
-  apiCall: () => Promise<T>,
-  ttlMs: number = 300000
-): Promise<T> {
-  const cache = LocalCache.getInstance();
-
-  // 檢查快取
-  const cached = cache.get<T>(key);
-  if (cached) {
-    console.log(`Cache hit for key: ${key}`);
-    return cached;
-  }
-
-  // 執行 API 調用
-  console.log(`Cache miss for key: ${key}, making API call`);
-  const result = await apiCall();
-
-  // 存入快取
-  cache.set(key, result, ttlMs);
-
-  return result;
-}
-
-/**
- * 生成快取鍵
- */
-export function generateCacheKey(prefix: string, ...params: any[]): string {
-  const paramString = params.map(p =>
-    typeof p === 'object' ? JSON.stringify(p) : String(p)
-  ).join('_');
-
-  return `${prefix}_${paramString}`;
-}
-
-/**
- * 性能監控工具
- */
-export class PerformanceMonitor {
-  private static timers = new Map<string, number>();
-
-  static start(label: string): void {
-    this.timers.set(label, performance.now());
-  }
-
-  static end(label: string): number {
-    const startTime = this.timers.get(label);
-    if (!startTime) {
-      console.warn(`No timer found for label: ${label}`);
-      return 0;
-    }
-
-    const duration = performance.now() - startTime;
-    this.timers.delete(label);
-
-    console.log(`⏱️ ${label}: ${duration.toFixed(2)}ms`);
-    return duration;
-  }
-
-  static measure<T>(label: string, fn: () => T): T {
-    this.start(label);
-    const result = fn();
-    this.end(label);
-    return result;
-  }
-
-  static async measureAsync<T>(label: string, fn: () => Promise<T>): Promise<T> {
-    this.start(label);
-    const result = await fn();
-    this.end(label);
-    return result;
-  }
-}
-
-/**
- * 圖片懶加載 Hook 替代方案
- */
-export function createIntersectionObserver(
-  callback: (entry: IntersectionObserverEntry) => void,
-  options?: IntersectionObserverInit
-): IntersectionObserver {
-  const defaultOptions: IntersectionObserverInit = {
-    root: null,
-    rootMargin: '50px',
-    threshold: 0.1,
-    ...options
-  };
-
-  return new IntersectionObserver((entries) => {
-    entries.forEach(callback);
-  }, defaultOptions);
-}
\ No newline at end of file
diff --git a/frontend/lib/services/auth.ts b/frontend/lib/services/auth.ts
index 3d9a7f4..514fd66 100644
--- a/frontend/lib/services/auth.ts
+++ b/frontend/lib/services/auth.ts
@@ -32,7 +32,9 @@ export interface AuthResponse {
   error?: string;
 }
 
-const API_BASE_URL = 'http://localhost:5008';
+import { BASE_URL } from '@/lib/config/api'
+
+const API_BASE_URL = BASE_URL;
 
 class AuthService {
   private async makeRequest<T>(
diff --git a/frontend/lib/services/flashcards.ts b/frontend/lib/services/flashcards.ts
index 79d1011..0afc129 100644
--- a/frontend/lib/services/flashcards.ts
+++ b/frontend/lib/services/flashcards.ts
@@ -380,7 +380,7 @@ class FlashcardsService {
   }> {
     try {
       const params = cardIds && cardIds.length > 0 ? `?cardIds=${cardIds.join(',')}` : '';
-      const result = await this.makeRequest(`/study/completed-tests${params}`);
+      const result = await this.makeRequest(`/review/completed-tests${params}`);
 
       return {
         success: true,
@@ -398,7 +398,7 @@ class FlashcardsService {
   }
 
   /**
-   * 記錄測驗完成狀態 (立即保存到StudyRecord表)
+   * 記錄測驗完成狀態 (立即保存到ReviewRecord表)
    */
   async recordTestCompletion(request: {
     flashcardId: string;
@@ -409,7 +409,7 @@ class FlashcardsService {
     responseTimeMs?: number;
   }): Promise<{ success: boolean; data: any | null; error?: string }> {
     try {
-      const result = await this.makeRequest('/study/record-test', {
+      const result = await this.makeRequest('/review/record-test', {
         method: 'POST',
         body: JSON.stringify({
           flashcardId: request.flashcardId,
diff --git a/frontend/lib/services/imageGeneration.ts b/frontend/lib/services/imageGeneration.ts
index 3ec984d..b67f4e0 100644
--- a/frontend/lib/services/imageGeneration.ts
+++ b/frontend/lib/services/imageGeneration.ts
@@ -1,4 +1,5 @@
 // Image Generation API service
+import { BASE_URL } from '@/lib/config/api'
 
 export interface ImageGenerationRequest {
   style: 'cartoon' | 'realistic' | 'minimal'
@@ -62,7 +63,7 @@ export interface ApiResponse<T> {
 }
 
 class ImageGenerationService {
-  private baseUrl = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008'
+  private baseUrl = BASE_URL
 
   private async makeRequest<T>(url: string, options: RequestInit = {}): Promise<ApiResponse<T>> {
     const token = localStorage.getItem('token')
diff --git a/frontend/lib/services/review/reviewService.ts b/frontend/lib/services/review/reviewService.ts
index f0a0373..958c65b 100644
--- a/frontend/lib/services/review/reviewService.ts
+++ b/frontend/lib/services/review/reviewService.ts
@@ -1,5 +1,5 @@
 import { flashcardsService } from '@/lib/services/flashcards'
-import { ExtendedFlashcard } from '@/store/useReviewSessionStore'
+import { ExtendedFlashcard } from '@/lib/types/review'
 import { TestItem } from '@/store/useTestQueueStore'
 
 // 複習會話服務
diff --git a/frontend/lib/services/studySession.ts b/frontend/lib/services/studySession.ts
deleted file mode 100644
index 2c31c7f..0000000
--- a/frontend/lib/services/studySession.ts
+++ /dev/null
@@ -1,167 +0,0 @@
-// 學習會話服務
-const API_BASE = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008';
-
-// 類型定義
-export interface StudySession {
-  sessionId: string;
-  totalCards: number;
-  totalTests: number;
-  currentCardIndex: number;
-  currentTestType?: string;
-  startedAt: string;
-}
-
-export interface CurrentTest {
-  sessionId: string;
-  testType: string;
-  card: Card;
-  progress: ProgressSummary;
-}
-
-export interface Card {
-  id: string;
-  word: string;
-  translation: string;
-  definition: string;
-  example: string;
-  exampleTranslation: string;
-  pronunciation: string;
-  difficultyLevel: string;
-}
-
-export interface ProgressSummary {
-  currentCardIndex: number;
-  totalCards: number;
-  completedTests: number;
-  totalTests: number;
-  completedCards: number;
-}
-
-export interface TestResult {
-  testType: string;
-  isCorrect: boolean;
-  userAnswer?: string;
-  confidenceLevel?: number;
-  responseTimeMs: number;
-}
-
-export interface SubmitTestResponse {
-  success: boolean;
-  isCardCompleted: boolean;
-  progress: ProgressSummary;
-  message: string;
-}
-
-export interface NextTest {
-  hasNextTest: boolean;
-  testType?: string;
-  sameCard: boolean;
-  message: string;
-}
-
-export interface Progress {
-  sessionId: string;
-  status: string;
-  currentCardIndex: number;
-  totalCards: number;
-  completedTests: number;
-  totalTests: number;
-  completedCards: number;
-  cards: CardProgress[];
-}
-
-export interface CardProgress {
-  cardId: string;
-  word: string;
-  plannedTests: string[];
-  completedTestsCount: number;
-  isCompleted: boolean;
-  tests: TestProgress[];
-}
-
-export interface TestProgress {
-  testType: string;
-  isCorrect: boolean;
-  completedAt: string;
-}
-
-export class StudySessionService {
-  private async makeRequest<T>(endpoint: string, options: RequestInit = {}): Promise<{ success: boolean; data: T | null; error?: string }> {
-    try {
-      const token = localStorage.getItem('auth_token');
-
-      const response = await fetch(`${API_BASE}${endpoint}`, {
-        headers: {
-          'Content-Type': 'application/json',
-          // 開發階段：不發送無效的token，讓後端使用測試用戶
-          // 'Authorization': token ? `Bearer ${token}` : '',
-          ...options.headers,
-        },
-        ...options,
-      });
-
-      if (!response.ok) {
-        const errorData = await response.json().catch(() => ({ error: 'Network error' }));
-        return { success: false, data: null, error: errorData.error || `HTTP ${response.status}` };
-      }
-
-      const result = await response.json();
-      return { success: result.Success || false, data: result.Data || null, error: result.Error };
-    } catch (error) {
-      console.error('API request failed:', error);
-      return { success: false, data: null, error: 'Network error' };
-    }
-  }
-
-  /**
-   * 開始新的學習會話
-   */
-  async startSession(): Promise<{ success: boolean; data: StudySession | null; error?: string }> {
-    return await this.makeRequest<StudySession>('/api/study/sessions/start', {
-      method: 'POST'
-    });
-  }
-
-  /**
-   * 獲取當前測驗
-   */
-  async getCurrentTest(sessionId: string): Promise<{ success: boolean; data: CurrentTest | null; error?: string }> {
-    return await this.makeRequest<CurrentTest>(`/api/study/sessions/${sessionId}/current-test`);
-  }
-
-  /**
-   * 提交測驗結果
-   */
-  async submitTest(sessionId: string, result: TestResult): Promise<{ success: boolean; data: SubmitTestResponse | null; error?: string }> {
-    return await this.makeRequest<SubmitTestResponse>(`/api/study/sessions/${sessionId}/submit-test`, {
-      method: 'POST',
-      body: JSON.stringify(result)
-    });
-  }
-
-  /**
-   * 獲取下一個測驗
-   */
-  async getNextTest(sessionId: string): Promise<{ success: boolean; data: NextTest | null; error?: string }> {
-    return await this.makeRequest<NextTest>(`/api/study/sessions/${sessionId}/next-test`);
-  }
-
-  /**
-   * 獲取詳細進度
-   */
-  async getProgress(sessionId: string): Promise<{ success: boolean; data: Progress | null; error?: string }> {
-    return await this.makeRequest<Progress>(`/api/study/sessions/${sessionId}/progress`);
-  }
-
-  /**
-   * 完成學習會話
-   */
-  async completeSession(sessionId: string): Promise<{ success: boolean; data: any | null; error?: string }> {
-    return await this.makeRequest(`/api/study/sessions/${sessionId}/complete`, {
-      method: 'PUT'
-    });
-  }
-}
-
-// 導出服務實例
-export const studySessionService = new StudySessionService();
\ No newline at end of file
diff --git a/frontend/lib/utils/cefrUtils.ts b/frontend/lib/utils/cefrUtils.ts
index ee507a9..4914774 100644
--- a/frontend/lib/utils/cefrUtils.ts
+++ b/frontend/lib/utils/cefrUtils.ts
@@ -97,4 +97,26 @@ export const isValidCEFRLevel = (level: string): level is CEFRLevel => {
  */
 export const getAllCEFRLevels = (): readonly CEFRLevel[] => {
   return CEFR_LEVELS
+}
+
+/**
+ * 根據CEFR等級獲取複習類型
+ * @param userCEFR 用戶CEFR等級
+ * @param wordCEFR 詞彙CEFR等級
+ * @returns 推薦的複習類型陣列
+ */
+export const getReviewTypesByCEFR = (userCEFR: string, wordCEFR: string): string[] => {
+  const userLevel = cefrToNumeric(userCEFR)
+  const wordLevel = cefrToNumeric(wordCEFR)
+  const difficulty = wordLevel - userLevel
+
+  if (userCEFR === 'A1') {
+    return ['flip-memory', 'vocab-choice']
+  } else if (difficulty < -1) {
+    return ['sentence-reorder', 'sentence-fill']
+  } else if (difficulty >= -1 && difficulty <= 1) {
+    return ['sentence-fill', 'sentence-reorder']
+  } else {
+    return ['flip-memory', 'vocab-choice']
+  }
 }
\ No newline at end of file
diff --git a/frontend/lib/utils/cn.ts b/frontend/lib/utils/cn.ts
deleted file mode 100644
index 2a7a4a7..0000000
--- a/frontend/lib/utils/cn.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-import { clsx, type ClassValue } from 'clsx'
-import { twMerge } from 'tailwind-merge'
-
-export function cn(...inputs: ClassValue[]) {
-  return twMerge(clsx(inputs))
-}
\ No newline at end of file
diff --git a/frontend/store/useReviewDataStore.ts b/frontend/store/useReviewDataStore.ts
index 7912549..5e84b1b 100644
--- a/frontend/store/useReviewDataStore.ts
+++ b/frontend/store/useReviewDataStore.ts
@@ -1,7 +1,7 @@
 import { create } from 'zustand'
 import { subscribeWithSelector } from 'zustand/middleware'
 import { flashcardsService } from '@/lib/services/flashcards'
-import { ExtendedFlashcard } from './useReviewSessionStore'
+import { ExtendedFlashcard } from '@/lib/types/review'
 
 // 數據狀態接口
 interface ReviewDataState {
diff --git a/frontend/types/review.ts b/frontend/types/review.ts
index 29b3e18..6d356ed 100644
--- a/frontend/types/review.ts
+++ b/frontend/types/review.ts
@@ -8,7 +8,7 @@ export interface ReviewCardData {
   translation: string
   pronunciation?: string
   synonyms: string[]
-  difficultyLevel: string
+  cefr: string
   exampleTranslation: string
   filledQuestionText?: string
   exampleImage?: string