diff --git a/frontend/lib/services/flashcards.ts b/frontend/lib/services/flashcards.ts
index 49e8ab5..3bd0648 100644
--- a/frontend/lib/services/flashcards.ts
+++ b/frontend/lib/services/flashcards.ts
@@ -1,18 +1,4 @@
-// Flashcards API service for handling flashcard operations
-
-export interface CardSet {
-  id: string;
-  name: string;
-  description: string;
-  color: string;
-  cardCount: number;
-  createdAt: string;
-  updatedAt: string;
-  isDefault: boolean;
-  progress: number;
-  lastStudied: string;
-  tags: string[];
-}
+// Flashcards API service
 
 export interface Flashcard {
   id: string;
@@ -27,27 +13,20 @@ export interface Flashcard {
   timesReviewed: number;
   isFavorite: boolean;
   nextReviewDate: string;
+  difficultyLevel: string;
   createdAt: string;
-  cardSet: {
-    name: string;
-    color: string;
-  };
-}
-
-export interface CreateCardSetRequest {
-  name: string;
-  description: string;
-  isPublic?: boolean;
+  updatedAt?: string; // 設為可選，因為模擬資料可能沒有
+  // 移除 cardSet 屬性
 }
 
 export interface CreateFlashcardRequest {
-  cardSetId?: string;
   word: string;
   translation: string;
   definition: string;
   pronunciation: string;
   partOfSpeech: string;
   example: string;
+  exampleTranslation?: string;
 }
 
 export interface ApiResponse<T> {
@@ -57,25 +36,13 @@ export interface ApiResponse<T> {
   message?: string;
 }
 
-const API_BASE_URL = 'http://localhost:5008';
-
 class FlashcardsService {
-  private getAuthToken(): string | null {
-    if (typeof window === 'undefined') return null;
-    return localStorage.getItem('auth_token');
-  }
+  private readonly baseURL = `${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008'}/api`;
 
-  private async makeRequest<T>(
-    endpoint: string,
-    options: RequestInit = {}
-  ): Promise<T> {
-    const token = this.getAuthToken();
-    const url = `${API_BASE_URL}/api${endpoint}`;
-
-    const response = await fetch(url, {
+  private async makeRequest<T>(endpoint: string, options: RequestInit = {}): Promise<T> {
+    const response = await fetch(`${this.baseURL}${endpoint}`, {
       headers: {
         'Content-Type': 'application/json',
-        ...(token && { 'Authorization': `Bearer ${token}` }),
         ...options.headers,
       },
       ...options,
@@ -89,50 +56,17 @@ class FlashcardsService {
     return response.json();
   }
 
-  // CardSets methods
-  async getCardSets(): Promise<ApiResponse<{ sets: CardSet[] }>> {
+  // 簡化的詞卡方法
+  async getFlashcards(search?: string, favoritesOnly: boolean = false): Promise<ApiResponse<{ flashcards: SimpleFlashcard[], count: number }>> {
     try {
-      return await this.makeRequest<ApiResponse<{ sets: CardSet[] }>>('/cardsets');
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to fetch card sets',
-      };
-    }
-  }
+      const params = new URLSearchParams();
+      if (search) params.append('search', search);
+      if (favoritesOnly) params.append('favoritesOnly', 'true');
 
-  async createCardSet(data: CreateCardSetRequest): Promise<ApiResponse<CardSet>> {
-    try {
-      return await this.makeRequest<ApiResponse<CardSet>>('/cardsets', {
-        method: 'POST',
-        body: JSON.stringify(data),
-      });
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to create card set',
-      };
-    }
-  }
+      const queryString = params.toString();
+      const endpoint = `/flashcards${queryString ? `?${queryString}` : ''}`;
 
-  async deleteCardSet(id: string): Promise<ApiResponse<void>> {
-    try {
-      return await this.makeRequest<ApiResponse<void>>(`/cardsets/${id}`, {
-        method: 'DELETE',
-      });
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to delete card set',
-      };
-    }
-  }
-
-  // Flashcards methods
-  async getFlashcards(cardSetId?: string): Promise<ApiResponse<{ flashcards: Flashcard[]; total: number; hasMore: boolean }>> {
-    try {
-      const query = cardSetId ? `?cardSetId=${cardSetId}` : '';
-      return await this.makeRequest<ApiResponse<{ flashcards: Flashcard[]; total: number; hasMore: boolean }>>(`/flashcards${query}`);
+      return await this.makeRequest<ApiResponse<{ flashcards: SimpleFlashcard[], count: number }>>(endpoint);
     } catch (error) {
       return {
         success: false,
@@ -141,7 +75,7 @@ class FlashcardsService {
     }
   }
 
-  async createFlashcard(data: CreateFlashcardRequest): Promise<ApiResponse<Flashcard>> {
+  async createFlashcard(data: CreateSimpleFlashcardRequest): Promise<ApiResponse<SimpleFlashcard>> {
     try {
       return await this.makeRequest<ApiResponse<Flashcard>>('/flashcards', {
         method: 'POST',
@@ -155,20 +89,6 @@ class FlashcardsService {
     }
   }
 
-  async updateFlashcard(id: string, data: Partial<CreateFlashcardRequest>): Promise<ApiResponse<Flashcard>> {
-    try {
-      return await this.makeRequest<ApiResponse<Flashcard>>(`/flashcards/${id}`, {
-        method: 'PUT',
-        body: JSON.stringify(data),
-      });
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to update flashcard',
-      };
-    }
-  }
-
   async deleteFlashcard(id: string): Promise<ApiResponse<void>> {
     try {
       return await this.makeRequest<ApiResponse<void>>(`/flashcards/${id}`, {
@@ -182,9 +102,34 @@ class FlashcardsService {
     }
   }
 
-  async toggleFavorite(id: string): Promise<ApiResponse<Flashcard>> {
+  async getFlashcard(id: string): Promise<ApiResponse<SimpleFlashcard>> {
     try {
-      return await this.makeRequest<ApiResponse<Flashcard>>(`/flashcards/${id}/favorite`, {
+      return await this.makeRequest<ApiResponse<Flashcard>>(`/flashcards/${id}`);
+    } catch (error) {
+      return {
+        success: false,
+        error: error instanceof Error ? error.message : 'Failed to get flashcard',
+      };
+    }
+  }
+
+  async updateFlashcard(id: string, data: CreateSimpleFlashcardRequest): Promise<ApiResponse<SimpleFlashcard>> {
+    try {
+      return await this.makeRequest<ApiResponse<Flashcard>>(`/flashcards/${id}`, {
+        method: 'PUT',
+        body: JSON.stringify(data),
+      });
+    } catch (error) {
+      return {
+        success: false,
+        error: error instanceof Error ? error.message : 'Failed to update flashcard',
+      };
+    }
+  }
+
+  async toggleFavorite(id: string): Promise<ApiResponse<void>> {
+    try {
+      return await this.makeRequest<ApiResponse<void>>(`/flashcards/${id}/favorite`, {
         method: 'POST',
       });
     } catch (error) {
@@ -194,52 +139,6 @@ class FlashcardsService {
       };
     }
   }
-
-  async ensureDefaultCardSet(): Promise<ApiResponse<CardSet>> {
-    try {
-      return await this.makeRequest<ApiResponse<CardSet>>('/cardsets/ensure-default', {
-        method: 'POST',
-      });
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to ensure default card set',
-      };
-    }
-  }
-
-  async batchCreateFlashcards(request: BatchCreateFlashcardsRequest): Promise<ApiResponse<BatchCreateFlashcardsResponse>> {
-    try {
-      return await this.makeRequest<ApiResponse<BatchCreateFlashcardsResponse>>('/flashcards/batch', {
-        method: 'POST',
-        body: JSON.stringify(request),
-      });
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to save flashcards',
-      };
-    }
-  }
-}
-
-// 新增批量創建相關介面
-export interface BatchCreateFlashcardsRequest {
-  cardSetId?: string;
-  cards: CreateFlashcardRequest[];
-}
-
-export interface BatchCreateFlashcardsResponse {
-  savedCards: SavedCard[];
-  savedCount: number;
-  errorCount: number;
-  errors: string[];
-}
-
-export interface SavedCard {
-  id: string;
-  word: string;
-  translation: string;
 }
 
 export const flashcardsService = new FlashcardsService();
\ No newline at end of file
diff --git a/frontend/lib/services/simplifiedFlashcards.ts b/frontend/lib/services/simplifiedFlashcards.ts
deleted file mode 100644
index 2e9e8a8..0000000
--- a/frontend/lib/services/simplifiedFlashcards.ts
+++ /dev/null
@@ -1,120 +0,0 @@
-// 簡化的 Flashcards API service - 移除 CardSets 概念
-
-export interface SimpleFlashcard {
-  id: string;
-  word: string;
-  translation: string;
-  definition: string;
-  partOfSpeech: string;
-  pronunciation: string;
-  example: string;
-  exampleTranslation?: string;
-  masteryLevel: number;
-  timesReviewed: number;
-  isFavorite: boolean;
-  nextReviewDate: string;
-  difficultyLevel: string;
-  createdAt: string;
-  updatedAt?: string; // 設為可選，因為模擬資料可能沒有
-  // 移除 cardSet 屬性
-}
-
-export interface CreateSimpleFlashcardRequest {
-  word: string;
-  translation: string;
-  definition: string;
-  pronunciation: string;
-  partOfSpeech: string;
-  example: string;
-  exampleTranslation?: string;
-  // 移除 cardSetId
-}
-
-export interface ApiResponse<T> {
-  success: boolean;
-  data?: T;
-  error?: string;
-  message?: string;
-}
-
-class SimplifiedFlashcardsService {
-  private readonly baseURL = `${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008'}/api`;
-
-  private async makeRequest<T>(endpoint: string, options: RequestInit = {}): Promise<T> {
-    const response = await fetch(`${this.baseURL}${endpoint}`, {
-      headers: {
-        'Content-Type': 'application/json',
-        ...options.headers,
-      },
-      ...options,
-    });
-
-    if (!response.ok) {
-      const errorData = await response.json().catch(() => ({ error: 'Network error' }));
-      throw new Error(errorData.error || errorData.details || `HTTP ${response.status}`);
-    }
-
-    return response.json();
-  }
-
-  // 簡化的詞卡方法
-  async getFlashcards(search?: string, favoritesOnly: boolean = false): Promise<ApiResponse<{ flashcards: SimpleFlashcard[], count: number }>> {
-    try {
-      const params = new URLSearchParams();
-      if (search) params.append('search', search);
-      if (favoritesOnly) params.append('favoritesOnly', 'true');
-
-      const queryString = params.toString();
-      const endpoint = `/flashcards-simple${queryString ? `?${queryString}` : ''}`;
-
-      return await this.makeRequest<ApiResponse<{ flashcards: SimpleFlashcard[], count: number }>>(endpoint);
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to fetch flashcards',
-      };
-    }
-  }
-
-  async createFlashcard(data: CreateSimpleFlashcardRequest): Promise<ApiResponse<SimpleFlashcard>> {
-    try {
-      return await this.makeRequest<ApiResponse<SimpleFlashcard>>('/flashcards-simple', {
-        method: 'POST',
-        body: JSON.stringify(data),
-      });
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to create flashcard',
-      };
-    }
-  }
-
-  async deleteFlashcard(id: string): Promise<ApiResponse<void>> {
-    try {
-      return await this.makeRequest<ApiResponse<void>>(`/flashcards-simple/${id}`, {
-        method: 'DELETE',
-      });
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to delete flashcard',
-      };
-    }
-  }
-
-  async toggleFavorite(id: string): Promise<ApiResponse<void>> {
-    try {
-      return await this.makeRequest<ApiResponse<void>>(`/flashcards-simple/${id}/favorite`, {
-        method: 'POST',
-      });
-    } catch (error) {
-      return {
-        success: false,
-        error: error instanceof Error ? error.message : 'Failed to toggle favorite',
-      };
-    }
-  }
-}
-
-export const simplifiedFlashcardsService = new SimplifiedFlashcardsService();
\ No newline at end of file