修复大小写切换后新输入字母不跟随转换，输入时根据当前大小写状态存储

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CLAUDE.md

@@ -21,19 +21,3 @@ xcodebuild -project LearnEnglish/LearnEnglish.xcodeproj -scheme LearnEnglish \
 - 部署目标为 iOS 26，模拟器必须是 iOS 26.x 运行时，否则安装时报系统版本过低。
 - 无测试 target、无 lint 配置，验证方式 = 编译。
 - Xcode 工程使用同步文件夹（objectVersion 77），在 `LearnEnglish/LearnEnglish/` 下新建 .swift 文件会自动加入 target，无需改 pbxproj。
-
-## 架构
-
-**数据流**：`Resources/words.json` → `WordStore.load()`（SceneDelegate 启动时加载一次）→ 通过初始化器逐层注入（`CategoryListViewController(store:)` → `WordListViewController(category:)` → 详情/测验）。词库模型 `WordBank`/`WordCategory`/`Word` 均为 Codable，见 `Models/Word.swift`。
-
-**words.json 格式**：每个单词单行 JSON 对象，字段为 `word`/`phonetic`/`meaning`/`example`/`exampleMeaning`，追加新词时保持该格式。编辑时注意同名单词可能出现在多个分类（如 orange 既是颜色也是水果），替换要限定在目标分类区块内。
-
-**页面流**：分类列表 → 单词列表（`WordCardCell`）→ 单词详情；单词列表底部"开始测验" → `QuizSetupViewController`（选模式、题量）→ `QuizViewController` → `QuizResultView`。
-
-**测验**：四种模式（英选汉/汉选英/拼写/默写，`QuizMode`）由同一个 `QuizViewController` 承载；题目由 `QuizGenerator.makeQuestions` 生成（选择题自动取 3 个干扰项，拼写题按 40% 比例挖空）。拼写/默写分别用 `SpellingInputView`/`DictationInputView` 自定义输入组件。新增测验相关结构放 `Models/Quiz.swift`。
-
-**发音**：`SpeechService.shared` 单例封装 `AVSpeechSynthesizer`（en-US），播放状态通过 `speakingDidChangeNotification` 广播，各页面监听后刷新喇叭按钮图标与可用状态。
-
-**设计系统**：`Utilities/Theme.swift` 集中管理色板（`Theme.Color`，含分类调色板 `category(at:)`）、圆角（`Theme.Metrics`）、字体（`Theme.Font`）；`UIView.setPressed`/`animateEntry` 为通用按压/入场动画。新 UI 元素应复用这些 token 而不是硬编码数值。`HairlineView` 是适配屏幕缩放的分隔线组件。
-
-**导航**：`SceneDelegate` 直接构建 `UINavigationController` 根控制器并设置 `window.tintColor`；各页面用 `navigationItem.largeTitleDisplayMode = .never` 关闭大标题。

LearnEnglish/LearnEnglish/Models/LearnedStore.swift

@@ -0,0 +1,90 @@
+import Foundation
+
+struct LearnedRecord: Codable {
+    let word: Word
+    var learnedAt: Date
+    var count: Int = 1
+    var correctCount: Int = 0
+
+    var accuracy: Int {
+        count > 0 ? Int(Double(correctCount) / Double(count) * 100) : 0
+    }
+}
+
+final class LearnedStore {
+    static let shared = LearnedStore()
+    private let key = "learned_records"
+
+    private(set) var records: [LearnedRecord] {
+        didSet {
+            guard let data = try? JSONEncoder().encode(records) else { return }
+            UserDefaults.standard.set(data, forKey: key)
+        }
+    }
+
+    private init() {
+        if let data = UserDefaults.standard.data(forKey: key),
+           let decoded = try? JSONDecoder().decode([LearnedRecord].self, from: data) {
+            records = decoded
+        } else {
+            records = []
+        }
+    }
+
+    func record(_ word: Word, correct: Bool) {
+        if let index = records.firstIndex(where: { $0.word.id == word.id }) {
+            records[index].learnedAt = Date()
+            records[index].count += 1
+            if correct { records[index].correctCount += 1 }
+        } else {
+            var rec = LearnedRecord(word: word, learnedAt: Date())
+            if correct { rec.correctCount = 1 }
+            records.append(rec)
+        }
+    }
+
+    func record(for word: Word) -> LearnedRecord? {
+        records.first { $0.word.id == word.id }
+    }
+
+    func isRecorded(_ word: Word) -> Bool {
+        records.contains { $0.word.id == word.id }
+    }
+
+    var sectioned: [(title: String, items: [LearnedRecord])] {
+        let sorted = records.sorted { $0.learnedAt > $1.learnedAt }
+        let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "zh_CN")
+        formatter.dateFormat = "yyyy-MM-dd"
+
+        var groups: [(String, [LearnedRecord])] = []
+        var seen: Set<String> = []
+        for record in sorted {
+            let dateStr = formatter.string(from: record.learnedAt)
+            let title = sectionTitle(dateStr)
+            if !seen.contains(title) {
+                groups.append((title, []))
+                seen.insert(title)
+            }
+            if let index = groups.firstIndex(where: { $0.0 == title }) {
+                groups[index].1.append(record)
+            }
+        }
+        return groups
+    }
+
+    private func sectionTitle(_ dateStr: String) -> String {
+        let today = DateFormatter()
+        today.locale = Locale(identifier: "zh_CN")
+        today.dateFormat = "yyyy-MM-dd"
+        let todayStr = today.string(from: Date())
+        if dateStr == todayStr { return "今天" }
+
+        let calendar = Calendar.current
+        if let yesterday = calendar.date(byAdding: .day, value: -1, to: Date()) {
+            let yesterdayStr = today.string(from: yesterday)
+            if dateStr == yesterdayStr { return "昨天" }
+        }
+        return dateStr
+    }
+}

LearnEnglish/LearnEnglish/Models/NumberWords.swift

@@ -151,7 +151,7 @@ enum NumberWords {
 
     static func randomWord() -> Word {
         let n = Int.random(in: 0...999_999_999)
-        return Word(word: english(n),
+        return Word(categoryId: "numbers", word: english(n),
                     phonetic: "/\(phonetic(n))/",
                     meaning: chinese(n),
                     example: "The number is \(english(n)).",
@@ -163,7 +163,7 @@ enum NumberWords {
     }
 
     private static func makeWord(_ n: Int) -> Word {
-        Word(word: english(n),
+        Word(categoryId: "numbers", word: english(n),
              phonetic: "/\(phonetic(n))/",
              meaning: chinese(n),
              example: "I can count to \(english(n)).",

LearnEnglish/LearnEnglish/Models/Quiz.swift

@@ -51,6 +51,27 @@ enum QuizGenerator {
         }
     }
 
+    static func recase(_ questions: [QuizQuestion], toUpper: Bool) -> [QuizQuestion] {
+        questions.map { q in
+            let word = q.word
+            let text = toUpper ? word.word.uppercased() : word.word.lowercased()
+            let recased = Word(categoryId: word.categoryId, word: text, phonetic: word.phonetic,
+                               meaning: word.meaning, example: word.example, exampleMeaning: word.exampleMeaning)
+            let blanked = q.blankedWord.map { ch -> String in
+                ch == "_" ? "_" : ch.uppercased()
+            }.joined()
+            let blankedWord = toUpper ? blanked.uppercased() : blanked.lowercased()
+            return QuizQuestion(
+                word: recased,
+                prompt: q.prompt,
+                options: q.options,
+                answer: text,
+                blankedWord: blankedWord,
+                blankPositions: q.blankPositions
+            )
+        }
+    }
+
     private static func promptText(_ word: Word, _ mode: QuizMode) -> String {
         switch mode {
         case .enToZh: return word.word

LearnEnglish/LearnEnglish/Models/Word.swift

@@ -9,14 +9,25 @@ struct WordCategory: Codable, Identifiable, Hashable {
     let id: String
     let name: String
     let icon: String
-    let words: [Word]
+    var words: [Word]
+    var subcategories: [Subcategory]?
+}
+
+struct Subcategory: Codable, Hashable {
+    let name: String
+    var words: [Word]
 }
 
 struct Word: Codable, Identifiable, Hashable {
-    var id: String { word }
+    var id: String { "\(categoryId)/\(word)" }
+    var categoryId: String = ""
     let word: String
     let phonetic: String
     let meaning: String
     let example: String
     let exampleMeaning: String
+
+    enum CodingKeys: String, CodingKey {
+        case word, phonetic, meaning, example, exampleMeaning
+    }
 }

LearnEnglish/LearnEnglish/Resources/words.json

@@ -52,47 +52,104 @@
       "id": "animals",
       "name": "动物",
       "icon": "pawprint.fill",
-      "words": [
-        { "word": "cat", "phonetic": "/kæt/", "meaning": "猫", "example": "The cat is cute.", "exampleMeaning": "这只猫很可爱。" },
-        { "word": "dog", "phonetic": "/dɔːɡ/", "meaning": "狗", "example": "The dog is running.", "exampleMeaning": "狗在跑。" },
-        { "word": "bird", "phonetic": "/bɜːrd/", "meaning": "鸟", "example": "The bird can fly.", "exampleMeaning": "鸟会飞。" },
-        { "word": "fish", "phonetic": "/fɪʃ/", "meaning": "鱼", "example": "The fish swims fast.", "exampleMeaning": "鱼游得很快。" },
-        { "word": "rabbit", "phonetic": "/ˈræbɪt/", "meaning": "兔子", "example": "The rabbit likes carrots.", "exampleMeaning": "兔子喜欢胡萝卜。" },
-        { "word": "tiger", "phonetic": "/ˈtaɪɡər/", "meaning": "老虎", "example": "The tiger is strong.", "exampleMeaning": "老虎很强壮。" },
-        { "word": "elephant", "phonetic": "/ˈelɪfənt/", "meaning": "大象", "example": "The elephant has a long nose.", "exampleMeaning": "大象有长长的鼻子。" },
-        { "word": "monkey", "phonetic": "/ˈmʌŋki/", "meaning": "猴子", "example": "The monkey eats bananas.", "exampleMeaning": "猴子吃香蕉。" },
-        { "word": "panda", "phonetic": "/ˈpændə/", "meaning": "熊猫", "example": "The panda is black and white.", "exampleMeaning": "熊猫是黑白相间的。" },
-        { "word": "lion", "phonetic": "/ˈlaɪən/", "meaning": "狮子", "example": "The lion is the king of animals.", "exampleMeaning": "狮子是动物之王。" },
-        { "word": "horse", "phonetic": "/hɔːrs/", "meaning": "马", "example": "The horse runs fast.", "exampleMeaning": "马跑得很快。" },
-        { "word": "sheep", "phonetic": "/ʃiːp/", "meaning": "绵羊", "example": "The sheep eats grass.", "exampleMeaning": "绵羊吃草。" },
-        { "word": "pig", "phonetic": "/pɪɡ/", "meaning": "猪", "example": "The pig is fat.", "exampleMeaning": "这头猪很胖。" },
-        { "word": "cow", "phonetic": "/kaʊ/", "meaning": "奶牛", "example": "The cow gives milk.", "exampleMeaning": "奶牛产奶。" },
-        { "word": "duck", "phonetic": "/dʌk/", "meaning": "鸭子", "example": "The duck swims in the pond.", "exampleMeaning": "鸭子在池塘里游泳。" },
-        { "word": "chicken", "phonetic": "/ˈtʃɪkɪn/", "meaning": "鸡", "example": "The chicken lays eggs.", "exampleMeaning": "母鸡下蛋。" },
-        { "word": "mouse", "phonetic": "/maʊs/", "meaning": "老鼠", "example": "The mouse likes cheese.", "exampleMeaning": "老鼠喜欢奶酪。" },
-        { "word": "snake", "phonetic": "/sneɪk/", "meaning": "蛇", "example": "The snake has no legs.", "exampleMeaning": "蛇没有腿。" },
-        { "word": "frog", "phonetic": "/frɔːɡ/", "meaning": "青蛙", "example": "The frog can jump high.", "exampleMeaning": "青蛙能跳得很高。" },
-        { "word": "bear", "phonetic": "/ber/", "meaning": "熊", "example": "The bear sleeps in winter.", "exampleMeaning": "熊在冬天睡觉。" },
-        { "word": "giraffe", "phonetic": "/dʒəˈræf/", "meaning": "长颈鹿", "example": "The giraffe is tall.", "exampleMeaning": "长颈鹿很高。" },
-        { "word": "zebra", "phonetic": "/ˈziːbrə/", "meaning": "斑马", "example": "The zebra has stripes.", "exampleMeaning": "斑马身上有条纹。" },
-        { "word": "wolf", "phonetic": "/wʊlf/", "meaning": "狼", "example": "The wolf howls at night.", "exampleMeaning": "狼在夜里嚎叫。" },
-        { "word": "fox", "phonetic": "/fɑːks/", "meaning": "狐狸", "example": "The fox is clever.", "exampleMeaning": "狐狸很聪明。" },
-        { "word": "deer", "phonetic": "/dɪr/", "meaning": "鹿", "example": "The deer runs fast.", "exampleMeaning": "鹿跑得很快。" },
-        { "word": "squirrel", "phonetic": "/ˈskwɜːrəl/", "meaning": "松鼠", "example": "The squirrel likes nuts.", "exampleMeaning": "松鼠喜欢坚果。" },
-        { "word": "penguin", "phonetic": "/ˈpeŋɡwɪn/", "meaning": "企鹅", "example": "The penguin cannot fly.", "exampleMeaning": "企鹅不会飞。" },
-        { "word": "dolphin", "phonetic": "/ˈdɑːlfɪn/", "meaning": "海豚", "example": "The dolphin swims fast.", "exampleMeaning": "海豚游得很快。" },
-        { "word": "whale", "phonetic": "/weɪl/", "meaning": "鲸鱼", "example": "The whale is very big.", "exampleMeaning": "鲸鱼非常大。" },
-        { "word": "shark", "phonetic": "/ʃɑːrk/", "meaning": "鲨鱼", "example": "The shark has sharp teeth.", "exampleMeaning": "鲨鱼有锋利的牙齿。" },
-        { "word": "turtle", "phonetic": "/ˈtɜːrtl/", "meaning": "乌龟", "example": "The turtle walks slowly.", "exampleMeaning": "乌龟走得很慢。" },
-        { "word": "owl", "phonetic": "/aʊl/", "meaning": "猫头鹰", "example": "The owl sleeps in the day.", "exampleMeaning": "猫头鹰白天睡觉。" },
-        { "word": "bee", "phonetic": "/biː/", "meaning": "蜜蜂", "example": "The bee makes honey.", "exampleMeaning": "蜜蜂酿蜜。" },
-        { "word": "butterfly", "phonetic": "/ˈbʌtərflaɪ/", "meaning": "蝴蝶", "example": "The butterfly is beautiful.", "exampleMeaning": "蝴蝶很漂亮。" },
-        { "word": "ant", "phonetic": "/ænt/", "meaning": "蚂蚁", "example": "The ant carries food.", "exampleMeaning": "蚂蚁搬运食物。" },
-        { "word": "spider", "phonetic": "/ˈspaɪdər/", "meaning": "蜘蛛", "example": "The spider makes a web.", "exampleMeaning": "蜘蛛织网。" },
-        { "word": "kangaroo", "phonetic": "/ˌkæŋɡəˈruː/", "meaning": "袋鼠", "example": "The kangaroo jumps high.", "exampleMeaning": "袋鼠跳得很高。" },
-        { "word": "koala", "phonetic": "/koʊˈɑːlə/", "meaning": "考拉", "example": "The koala sleeps a lot.", "exampleMeaning": "考拉睡很多觉。" },
-        { "word": "crocodile", "phonetic": "/ˈkrɑːkədaɪl/", "meaning": "鳄鱼", "example": "The crocodile has a big mouth.", "exampleMeaning": "鳄鱼有一张大嘴。" },
-        { "word": "camel", "phonetic": "/ˈkæml/", "meaning": "骆驼", "example": "The camel lives in the desert.", "exampleMeaning": "骆驼生活在沙漠里。" }
+      "words": [],
+      "subcategories": [
+        {
+          "name": "陆地动物",
+          "words": [
+            { "word": "cat", "phonetic": "/kæt/", "meaning": "猫", "example": "The cat is cute.", "exampleMeaning": "这只猫很可爱。" },
+            { "word": "dog", "phonetic": "/dɔːɡ/", "meaning": "狗", "example": "The dog is running.", "exampleMeaning": "狗在跑。" },
+            { "word": "rabbit", "phonetic": "/ˈræbɪt/", "meaning": "兔子", "example": "The rabbit likes carrots.", "exampleMeaning": "兔子喜欢胡萝卜。" },
+            { "word": "tiger", "phonetic": "/ˈtaɪɡər/", "meaning": "老虎", "example": "The tiger is strong.", "exampleMeaning": "老虎很强壮。" },
+            { "word": "elephant", "phonetic": "/ˈelɪfənt/", "meaning": "大象", "example": "The elephant has a long nose.", "exampleMeaning": "大象有长长的鼻子。" },
+            { "word": "monkey", "phonetic": "/ˈmʌŋki/", "meaning": "猴子", "example": "The monkey eats bananas.", "exampleMeaning": "猴子吃香蕉。" },
+            { "word": "panda", "phonetic": "/ˈpændə/", "meaning": "熊猫", "example": "The panda is black and white.", "exampleMeaning": "熊猫是黑白相间的。" },
+            { "word": "lion", "phonetic": "/ˈlaɪən/", "meaning": "狮子", "example": "The lion is the king of animals.", "exampleMeaning": "狮子是动物之王。" },
+            { "word": "horse", "phonetic": "/hɔːrs/", "meaning": "马", "example": "The horse runs fast.", "exampleMeaning": "马跑得很快。" },
+            { "word": "sheep", "phonetic": "/ʃiːp/", "meaning": "绵羊", "example": "The sheep eats grass.", "exampleMeaning": "绵羊吃草。" },
+            { "word": "pig", "phonetic": "/pɪɡ/", "meaning": "猪", "example": "The pig is fat.", "exampleMeaning": "这头猪很胖。" },
+            { "word": "cow", "phonetic": "/kaʊ/", "meaning": "奶牛", "example": "The cow gives milk.", "exampleMeaning": "奶牛产奶。" },
+            { "word": "chicken", "phonetic": "/ˈtʃɪkɪn/", "meaning": "鸡", "example": "The chicken lays eggs.", "exampleMeaning": "母鸡下蛋。" },
+            { "word": "mouse", "phonetic": "/maʊs/", "meaning": "老鼠", "example": "The mouse likes cheese.", "exampleMeaning": "老鼠喜欢奶酪。" },
+            { "word": "snake", "phonetic": "/sneɪk/", "meaning": "蛇", "example": "The snake has no legs.", "exampleMeaning": "蛇没有腿。" },
+            { "word": "bear", "phonetic": "/ber/", "meaning": "熊", "example": "The bear sleeps in winter.", "exampleMeaning": "熊在冬天睡觉。" },
+            { "word": "giraffe", "phonetic": "/dʒəˈræf/", "meaning": "长颈鹿", "example": "The giraffe is tall.", "exampleMeaning": "长颈鹿很高。" },
+            { "word": "zebra", "phonetic": "/ˈziːbrə/", "meaning": "斑马", "example": "The zebra has stripes.", "exampleMeaning": "斑马身上有条纹。" },
+            { "word": "wolf", "phonetic": "/wʊlf/", "meaning": "狼", "example": "The wolf howls at night.", "exampleMeaning": "狼在夜里嚎叫。" },
+            { "word": "fox", "phonetic": "/fɑːks/", "meaning": "狐狸", "example": "The fox is clever.", "exampleMeaning": "狐狸很聪明。" },
+            { "word": "deer", "phonetic": "/dɪr/", "meaning": "鹿", "example": "The deer runs fast.", "exampleMeaning": "鹿跑得很快。" },
+            { "word": "squirrel", "phonetic": "/ˈskwɜːrəl/", "meaning": "松鼠", "example": "The squirrel likes nuts.", "exampleMeaning": "松鼠喜欢坚果。" },
+            { "word": "turtle", "phonetic": "/ˈtɜːrtl/", "meaning": "乌龟", "example": "The turtle walks slowly.", "exampleMeaning": "乌龟走得很慢。" },
+            { "word": "ant", "phonetic": "/ænt/", "meaning": "蚂蚁", "example": "The ant carries food.", "exampleMeaning": "蚂蚁搬运食物。" },
+            { "word": "spider", "phonetic": "/ˈspaɪdər/", "meaning": "蜘蛛", "example": "The spider makes a web.", "exampleMeaning": "蜘蛛织网。" },
+            { "word": "kangaroo", "phonetic": "/ˌkæŋɡəˈruː/", "meaning": "袋鼠", "example": "The kangaroo jumps high.", "exampleMeaning": "袋鼠跳得很高。" },
+            { "word": "koala", "phonetic": "/koʊˈɑːlə/", "meaning": "考拉", "example": "The koala sleeps a lot.", "exampleMeaning": "考拉睡很多觉。" },
+            { "word": "crocodile", "phonetic": "/ˈkrɑːkədaɪl/", "meaning": "鳄鱼", "example": "The crocodile has a big mouth.", "exampleMeaning": "鳄鱼有一张大嘴。" },
+            { "word": "camel", "phonetic": "/ˈkæml/", "meaning": "骆驼", "example": "The camel lives in the desert.", "exampleMeaning": "骆驼生活在沙漠里。" }
+          ]
+        },
+        {
+          "name": "飞翔动物",
+          "words": [
+            { "word": "bird", "phonetic": "/bɜːrd/", "meaning": "鸟", "example": "The bird can fly.", "exampleMeaning": "鸟会飞。" },
+            { "word": "owl", "phonetic": "/aʊl/", "meaning": "猫头鹰", "example": "The owl sleeps in the day.", "exampleMeaning": "猫头鹰白天睡觉。" },
+            { "word": "bee", "phonetic": "/biː/", "meaning": "蜜蜂", "example": "The bee makes honey.", "exampleMeaning": "蜜蜂酿蜜。" },
+            { "word": "butterfly", "phonetic": "/ˈbʌtərflaɪ/", "meaning": "蝴蝶", "example": "The butterfly is beautiful.", "exampleMeaning": "蝴蝶很漂亮。" },
+            { "word": "eagle", "phonetic": "/ˈiːɡl/", "meaning": "鹰", "example": "The eagle flies high.", "exampleMeaning": "鹰飞得很高。" },
+            { "word": "crow", "phonetic": "/kroʊ/", "meaning": "乌鸦", "example": "The crow is black.", "exampleMeaning": "乌鸦是黑色的。" },
+            { "word": "pigeon", "phonetic": "/ˈpɪdʒɪn/", "meaning": "鸽子", "example": "The pigeon lives in the city.", "exampleMeaning": "鸽子生活在城市里。" },
+            { "word": "parrot", "phonetic": "/ˈpærət/", "meaning": "鹦鹉", "example": "The parrot can talk.", "exampleMeaning": "鹦鹉会说话。" },
+            { "word": "sparrow", "phonetic": "/ˈspæroʊ/", "meaning": "麻雀", "example": "The sparrow is small.", "exampleMeaning": "麻雀很小。" },
+            { "word": "swallow", "phonetic": "/ˈswɑːloʊ/", "meaning": "燕子", "example": "The swallow flies fast.", "exampleMeaning": "燕子飞得很快。" },
+            { "word": "bat", "phonetic": "/bæt/", "meaning": "蝙蝠", "example": "The bat flies at night.", "exampleMeaning": "蝙蝠在夜里飞。" },
+            { "word": "seagull", "phonetic": "/ˈsiːɡʌl/", "meaning": "海鸥", "example": "The seagull flies over the sea.", "exampleMeaning": "海鸥飞过海面。" },
+            { "word": "hawk", "phonetic": "/hɔːk/", "meaning": "隼", "example": "The hawk can see far.", "exampleMeaning": "隼能看得很远。" },
+            { "word": "woodpecker", "phonetic": "/ˈwʊdpekər/", "meaning": "啄木鸟", "example": "The woodpecker pecks trees.", "exampleMeaning": "啄木鸟啄树。" },
+            { "word": "dragonfly", "phonetic": "/ˈdræɡənflaɪ/", "meaning": "蜻蜓", "example": "The dragonfly has four wings.", "exampleMeaning": "蜻蜓有四只翅膀。" },
+            { "word": "mosquito", "phonetic": "/məˈskiːtoʊ/", "meaning": "蚊子", "example": "The mosquito bites me.", "exampleMeaning": "蚊子咬我。" }
+          ]
+        },
+        {
+          "name": "水禽",
+          "words": [
+            { "word": "duck", "phonetic": "/dʌk/", "meaning": "鸭子", "example": "The duck swims in the pond.", "exampleMeaning": "鸭子在池塘里游泳。" },
+            { "word": "swan", "phonetic": "/swɑːn/", "meaning": "天鹅", "example": "The swan is white.", "exampleMeaning": "天鹅是白色的。" },
+            { "word": "penguin", "phonetic": "/ˈpeŋɡwɪn/", "meaning": "企鹅", "example": "The penguin cannot fly.", "exampleMeaning": "企鹅不会飞。" },
+            { "word": "heron", "phonetic": "/ˈhɛrən/", "meaning": "苍鹭", "example": "The heron stands in the river.", "exampleMeaning": "苍鹭站在河里。" }
+          ]
+        },
+        {
+          "name": "两栖动物",
+          "words": [
+            { "word": "frog", "phonetic": "/frɔːɡ/", "meaning": "青蛙", "example": "The frog can jump high.", "exampleMeaning": "青蛙能跳得很高。" },
+            { "word": "tadpole", "phonetic": "/ˈtædpoʊl/", "meaning": "蝌蚪", "example": "The tadpole will become a frog.", "exampleMeaning": "蝌蚪会变成青蛙。" },
+            { "word": "newt", "phonetic": "/nuːt/", "meaning": "蝾螈", "example": "The newt lives in the pond.", "exampleMeaning": "蝾螈生活在池塘里。" }
+          ]
+        },
+        {
+          "name": "水中动物",
+          "words": [
+            { "word": "fish", "phonetic": "/fɪʃ/", "meaning": "鱼", "example": "The fish swims fast.", "exampleMeaning": "鱼游得很快。" },
+            { "word": "crayfish", "phonetic": "/ˈkreɪfɪʃ/", "meaning": "小龙虾", "example": "The crayfish lives in the river.", "exampleMeaning": "小龙虾生活在河里。" },
+            { "word": "loach", "phonetic": "/loʊtʃ/", "meaning": "泥鳅", "example": "The loach hides in the mud.", "exampleMeaning": "泥鳅躲在泥里。" },
+            { "word": "carp", "phonetic": "/kɑːrp/", "meaning": "鲤鱼", "example": "The carp swims in the pond.", "exampleMeaning": "鲤鱼在池塘里游泳。" },
+            { "word": "goldfish", "phonetic": "/ˈɡoʊldfɪʃ/", "meaning": "金鱼", "example": "The goldfish is orange.", "exampleMeaning": "金鱼是橙色的。" },
+            { "word": "eel", "phonetic": "/iːl/", "meaning": "鳗鱼", "example": "The eel is long and thin.", "exampleMeaning": "鳗鱼又长又细。" },
+            { "word": "crab", "phonetic": "/kræb/", "meaning": "螃蟹", "example": "The crab walks sideways.", "exampleMeaning": "螃蟹横着走。" },
+            { "word": "shrimp", "phonetic": "/ʃrɪmp/", "meaning": "虾", "example": "The shrimp is small.", "exampleMeaning": "虾很小。" },
+            { "word": "otter", "phonetic": "/ˈɑːtər/", "meaning": "水獭", "example": "The otter swims in the river.", "exampleMeaning": "水獭在河里游泳。" },
+            { "word": "beaver", "phonetic": "/ˈbiːvər/", "meaning": "河狸", "example": "The beaver builds a dam.", "exampleMeaning": "河狸筑水坝。" },
+            { "word": "catfish", "phonetic": "/ˈkætfɪʃ/", "meaning": "鲶鱼", "example": "The catfish has whiskers.", "exampleMeaning": "鲶鱼有胡须。" },
+            { "word": "trout", "phonetic": "/traʊt/", "meaning": "鳟鱼", "example": "The trout swims upstream.", "exampleMeaning": "鳟鱼往上游。" },
+            { "word": "salmon", "phonetic": "/ˈsæmən/", "meaning": "鲑鱼", "example": "The salmon swims up the river.", "exampleMeaning": "鲑鱼游到上游。" },
+            { "word": "leech", "phonetic": "/liːtʃ/", "meaning": "水蛭", "example": "The leech lives in the water.", "exampleMeaning": "水蛭生活在水里。" },
+            { "word": "clam", "phonetic": "/klæm/", "meaning": "蚌", "example": "The clam has a shell.", "exampleMeaning": "蚌有壳。" },
+            { "word": "sturgeon", "phonetic": "/ˈstɜːrdʒən/", "meaning": "鲟鱼", "example": "The sturgeon is a big fish.", "exampleMeaning": "鲟鱼是一种大鱼。" },
+            { "word": "dolphin", "phonetic": "/ˈdɑːlfɪn/", "meaning": "海豚", "example": "The dolphin swims fast.", "exampleMeaning": "海豚游得很快。" },
+            { "word": "whale", "phonetic": "/weɪl/", "meaning": "鲸鱼", "example": "The whale is very big.", "exampleMeaning": "鲸鱼非常大。" },
+            { "word": "shark", "phonetic": "/ʃɑːrk/", "meaning": "鲨鱼", "example": "The shark has sharp teeth.", "exampleMeaning": "鲨鱼有锋利的牙齿。" }
+          ]
+        }
       ]
     },
     {
@@ -208,7 +265,252 @@
         { "word": "granddaughter", "phonetic": "/ˈɡrændɔːtər/", "meaning": "孙女/外孙女", "example": "His granddaughter can sing.", "exampleMeaning": "他的孙女会唱歌。" },
         { "word": "nephew", "phonetic": "/ˈnefjuː/", "meaning": "侄子/外甥", "example": "My nephew is ten.", "exampleMeaning": "我侄子十岁。" },
         { "word": "niece", "phonetic": "/niːs/", "meaning": "侄女/外甥女", "example": "My niece likes drawing.", "exampleMeaning": "我侄女喜欢画画。" },
-        { "word": "grandparent", "phonetic": "/ˈɡrænperənt/", "meaning": "祖父母/外祖父母", "example": "My grandparents live in the country.", "exampleMeaning": "我的祖父母住在乡下。" }
+        { "word": "grandparent", "phonetic": "/ˈɡrænperənt/", "meaning": "祖父母/外祖父母", "example": "My grandparents live in the country.", "exampleMeaning": "我的祖父母住在乡下。" },
+        { "word": "family", "phonetic": "/ˈfæməli/", "meaning": "家庭", "example": "I love my family.", "exampleMeaning": "我爱我的家庭。" },
+        { "word": "child", "phonetic": "/tʃaɪld/", "meaning": "孩子", "example": "The child is playing.", "exampleMeaning": "孩子在玩。" },
+        { "word": "children", "phonetic": "/ˈtʃɪldrən/", "meaning": "孩子们", "example": "The children are at school.", "exampleMeaning": "孩子们在学校。" },
+        { "word": "sibling", "phonetic": "/ˈsɪblɪŋ/", "meaning": "兄弟姐妹", "example": "I have two siblings.", "exampleMeaning": "我有两个兄弟姐妹。" },
+        { "word": "relative", "phonetic": "/ˈrelətɪv/", "meaning": "亲戚", "example": "We visit relatives during the holiday.", "exampleMeaning": "我们假期走亲戚。" },
+        { "word": "couple", "phonetic": "/ˈkʌpl/", "meaning": "夫妻", "example": "The couple is walking hand in hand.", "exampleMeaning": "那对夫妻手牵手散步。" },
+        { "word": "spouse", "phonetic": "/spaʊs/", "meaning": "配偶", "example": "My spouse and I like to travel.", "exampleMeaning": "我和我配偶喜欢旅行。" },
+        { "word": "boyfriend", "phonetic": "/ˈbɔɪfrend/", "meaning": "男朋友", "example": "Her boyfriend is kind.", "exampleMeaning": "她男朋友很友善。" },
+        { "word": "girlfriend", "phonetic": "/ˈɡɜːrlfrend/", "meaning": "女朋友", "example": "His girlfriend is a nurse.", "exampleMeaning": "他女朋友是一名护士。" },
+        { "word": "father-in-law", "phonetic": "/ˈfɑːðər ɪn lɔː/", "meaning": "岳父/公公", "example": "My father-in-law is retired.", "exampleMeaning": "我岳父退休了。" },
+        { "word": "mother-in-law", "phonetic": "/ˈmʌðər ɪn lɔː/", "meaning": "岳母/婆婆", "example": "My mother-in-law is a great cook.", "exampleMeaning": "我婆婆做饭很好吃。" },
+        { "word": "brother-in-law", "phonetic": "/ˈbrʌðər ɪn lɔː/", "meaning": "姐夫/妹夫/大舅子", "example": "My brother-in-law works in Shanghai.", "exampleMeaning": "我姐夫在上海工作。" },
+        { "word": "sister-in-law", "phonetic": "/ˈsɪstər ɪn lɔː/", "meaning": "嫂子/弟媳/大姑子", "example": "My sister-in-law teaches English.", "exampleMeaning": "我嫂子教英语。" },
+        { "word": "twin", "phonetic": "/twɪn/", "meaning": "双胞胎", "example": "The twins look the same.", "exampleMeaning": "这对双胞胎长得一样。" },
+        { "word": "stepfather", "phonetic": "/ˈstepfɑːðər/", "meaning": "继父", "example": "My stepfather is very caring.", "exampleMeaning": "我的继父很体贴。" },
+        { "word": "stepmother", "phonetic": "/ˈstepmʌðər/", "meaning": "继母", "example": "Her stepmother is nice to her.", "exampleMeaning": "她的继母对她很好。" }
+      ]
+    },
+    {
+      "id": "food_drink",
+      "name": "饮食",
+      "icon": "fork.knife",
+      "words": [],
+      "subcategories": [
+        {
+          "name": "主食",
+          "words": [
+            { "word": "rice", "phonetic": "/raɪs/", "meaning": "米饭", "example": "I eat rice every day.", "exampleMeaning": "我每天吃米饭。" },
+            { "word": "bread", "phonetic": "/bred/", "meaning": "面包", "example": "I have bread for breakfast.", "exampleMeaning": "我早餐吃面包。" },
+            { "word": "noodle", "phonetic": "/ˈnuːdl/", "meaning": "面条", "example": "I like beef noodles.", "exampleMeaning": "我喜欢牛肉面。" },
+            { "word": "dumpling", "phonetic": "/ˈdʌmplɪŋ/", "meaning": "饺子", "example": "We make dumplings together.", "exampleMeaning": "我们一起包饺子。" }
+          ]
+        },
+        {
+          "name": "肉类",
+          "words": [
+            { "word": "meat", "phonetic": "/miːt/", "meaning": "肉", "example": "I like to eat meat.", "exampleMeaning": "我喜欢吃肉。" },
+            { "word": "beef", "phonetic": "/biːf/", "meaning": "牛肉", "example": "The beef is tender.", "exampleMeaning": "牛肉很嫩。" },
+            { "word": "pork", "phonetic": "/pɔːrk/", "meaning": "猪肉", "example": "I don't eat pork.", "exampleMeaning": "我不吃猪肉。" },
+            { "word": "chicken", "phonetic": "/ˈtʃɪkɪn/", "meaning": "鸡肉", "example": "Fried chicken is popular.", "exampleMeaning": "炸鸡很受欢迎。" },
+            { "word": "egg", "phonetic": "/eɡ/", "meaning": "鸡蛋", "example": "I have an egg for breakfast.", "exampleMeaning": "我早餐吃一个鸡蛋。" }
+          ]
+        },
+        {
+          "name": "蔬菜",
+          "words": [
+            { "word": "vegetable", "phonetic": "/ˈvedʒtəbl/", "meaning": "蔬菜", "example": "Eat more vegetables.", "exampleMeaning": "多吃蔬菜。" },
+            { "word": "carrot", "phonetic": "/ˈkærət/", "meaning": "胡萝卜", "example": "Rabbits like carrots.", "exampleMeaning": "兔子喜欢胡萝卜。" },
+            { "word": "tomato", "phonetic": "/təˈmeɪtoʊ/", "meaning": "番茄", "example": "The tomato is red.", "exampleMeaning": "番茄是红色的。" },
+            { "word": "potato", "phonetic": "/pəˈteɪtoʊ/", "meaning": "土豆", "example": "Potatoes grow underground.", "exampleMeaning": "土豆长在地下。" },
+            { "word": "onion", "phonetic": "/ˈʌnjən/", "meaning": "洋葱", "example": "The onion makes me cry.", "exampleMeaning": "洋葱让我流泪。" },
+            { "word": "cucumber", "phonetic": "/ˈkjuːkʌmbər/", "meaning": "黄瓜", "example": "The cucumber is fresh.", "exampleMeaning": "黄瓜很新鲜。" },
+            { "word": "cabbage", "phonetic": "/ˈkæbɪdʒ/", "meaning": "卷心菜", "example": "Cabbage is good for health.", "exampleMeaning": "卷心菜对健康有好处。" }
+          ]
+        },
+        {
+          "name": "饮品",
+          "words": [
+            { "word": "water", "phonetic": "/ˈwɔːtər/", "meaning": "水", "example": "I drink water every day.", "exampleMeaning": "我每天喝水。" },
+            { "word": "milk", "phonetic": "/mɪlk/", "meaning": "牛奶", "example": "I drink a glass of milk.", "exampleMeaning": "我喝一杯牛奶。" },
+            { "word": "juice", "phonetic": "/dʒuːs/", "meaning": "果汁", "example": "Orange juice is sweet.", "exampleMeaning": "橙汁很甜。" },
+            { "word": "tea", "phonetic": "/tiː/", "meaning": "茶", "example": "I drink tea in the afternoon.", "exampleMeaning": "我下午喝茶。" },
+            { "word": "coffee", "phonetic": "/ˈkɔːfi/", "meaning": "咖啡", "example": "I need a cup of coffee.", "exampleMeaning": "我需要一杯咖啡。" },
+            { "word": "beer", "phonetic": "/bɪr/", "meaning": "啤酒", "example": "He drinks beer with friends.", "exampleMeaning": "他和朋友喝啤酒。" },
+            { "word": "wine", "phonetic": "/waɪn/", "meaning": "葡萄酒", "example": "Red wine is good for health.", "exampleMeaning": "红酒对健康有好处。" }
+          ]
+        },
+        {
+          "name": "调料",
+          "words": [
+            { "word": "salt", "phonetic": "/sɔːlt/", "meaning": "盐", "example": "Don't add too much salt.", "exampleMeaning": "不要加太多盐。" },
+            { "word": "sugar", "phonetic": "/ˈʃʊɡər/", "meaning": "糖", "example": "I put sugar in my coffee.", "exampleMeaning": "我在咖啡里加糖。" },
+            { "word": "oil", "phonetic": "/ɔɪl/", "meaning": "油", "example": "Add some oil to the pan.", "exampleMeaning": "往锅里加点油。" },
+            { "word": "sauce", "phonetic": "/sɔːs/", "meaning": "酱", "example": "The sauce is delicious.", "exampleMeaning": "这个酱很好吃。" }
+          ]
+        },
+        {
+          "name": "餐食",
+          "words": [
+            { "word": "breakfast", "phonetic": "/ˈbrekfəst/", "meaning": "早餐", "example": "Breakfast is the most important meal.", "exampleMeaning": "早餐是最重要的一餐。" },
+            { "word": "lunch", "phonetic": "/lʌntʃ/", "meaning": "午餐", "example": "I have lunch at twelve.", "exampleMeaning": "我十二点吃午餐。" },
+            { "word": "dinner", "phonetic": "/ˈdɪnər/", "meaning": "晚餐", "example": "We have dinner at six.", "exampleMeaning": "我们六点吃晚餐。" },
+            { "word": "morning tea", "phonetic": "/ˈmɔːrnɪŋ tiː/", "meaning": "上午茶", "example": "We had morning tea at ten.", "exampleMeaning": "我们十点喝上午茶。" },
+            { "word": "afternoon tea", "phonetic": "/ˌæftərˈnuːn tiː/", "meaning": "下午茶", "example": "Afternoon tea is a British tradition.", "exampleMeaning": "下午茶是英国传统。" },
+            { "word": "midnight snack", "phonetic": "/ˈmɪdnaɪt snæk/", "meaning": "夜宵", "example": "I had a midnight snack before bed.", "exampleMeaning": "我睡前吃了夜宵。" }
+          ]
+        },
+        {
+          "name": "零食甜品",
+          "words": [
+            { "word": "cake", "phonetic": "/keɪk/", "meaning": "蛋糕", "example": "I like chocolate cake.", "exampleMeaning": "我喜欢巧克力蛋糕。" },
+            { "word": "cookie", "phonetic": "/ˈkʊki/", "meaning": "饼干", "example": "The cookie is crunchy.", "exampleMeaning": "饼干很脆。" },
+            { "word": "ice cream", "phonetic": "/ˌaɪs ˈkriːm/", "meaning": "冰淇淋", "example": "Ice cream is cold and sweet.", "exampleMeaning": "冰淇淋又冰又甜。" },
+            { "word": "chocolate", "phonetic": "/ˈtʃɔːklət/", "meaning": "巧克力", "example": "I love dark chocolate.", "exampleMeaning": "我爱黑巧克力。" },
+            { "word": "candy", "phonetic": "/ˈkændi/", "meaning": "糖果", "example": "The child likes candy.", "exampleMeaning": "小孩喜欢糖果。" }
+          ]
+        },
+        {
+          "name": "其他",
+          "words": [
+            { "word": "sandwich", "phonetic": "/ˈsænwɪtʃ/", "meaning": "三明治", "example": "I made a sandwich for lunch.", "exampleMeaning": "我做了三明治当午餐。" },
+            { "word": "pizza", "phonetic": "/ˈpiːtsə/", "meaning": "披萨", "example": "Pizza is from Italy.", "exampleMeaning": "披萨来自意大利。" },
+            { "word": "hamburger", "phonetic": "/ˈhæmbɜːrɡər/", "meaning": "汉堡", "example": "The hamburger is big.", "exampleMeaning": "这个汉堡很大。" },
+            { "word": "cheese", "phonetic": "/tʃiːz/", "meaning": "奶酪", "example": "Cheese is made from milk.", "exampleMeaning": "奶酪是用牛奶做的。" },
+            { "word": "butter", "phonetic": "/ˈbʌtər/", "meaning": "黄油", "example": "I spread butter on bread.", "exampleMeaning": "我在面包上涂黄油。" },
+            { "word": "soup", "phonetic": "/suːp/", "meaning": "汤", "example": "The soup is hot.", "exampleMeaning": "汤是热的。" }
+          ]
+        }
+      ]
+    },
+    {
+      "id": "direction",
+      "name": "方位",
+      "icon": "location.north.line",
+      "words": [],
+      "subcategories": [
+        {
+          "name": "罗盘方向",
+          "words": [
+            { "word": "north", "phonetic": "/nɔːrθ/", "meaning": "北", "example": "The wind blows from the north.", "exampleMeaning": "风从北边吹来。" },
+            { "word": "south", "phonetic": "/saʊθ/", "meaning": "南", "example": "Birds fly south in winter.", "exampleMeaning": "鸟儿冬天飞向南方。" },
+            { "word": "east", "phonetic": "/iːst/", "meaning": "东", "example": "The sun rises in the east.", "exampleMeaning": "太阳从东边升起。" },
+            { "word": "west", "phonetic": "/west/", "meaning": "西", "example": "The sun sets in the west.", "exampleMeaning": "太阳从西边落下。" },
+            { "word": "northeast", "phonetic": "/ˌnɔːrθˈiːst/", "meaning": "东北", "example": "The wind comes from the northeast.", "exampleMeaning": "风从东北方向吹来。" },
+            { "word": "northwest", "phonetic": "/ˌnɔːrθˈwest/", "meaning": "西北", "example": "The mountain is northwest of the city.", "exampleMeaning": "山在城市的西北方向。" },
+            { "word": "southeast", "phonetic": "/ˌsaʊθˈiːst/", "meaning": "东南", "example": "The river flows to the southeast.", "exampleMeaning": "河流向东南方。" },
+            { "word": "southwest", "phonetic": "/ˌsaʊθˈwest/", "meaning": "西南", "example": "The desert is southwest of here.", "exampleMeaning": "沙漠在这儿的西南方。" }
+          ]
+        },
+        {
+          "name": "相对方位",
+          "words": [
+            { "word": "front", "phonetic": "/frʌnt/", "meaning": "前面", "example": "Please stand at the front.", "exampleMeaning": "请站在前面。" },
+            { "word": "back", "phonetic": "/bæk/", "meaning": "后面", "example": "The garden is at the back.", "exampleMeaning": "花园在后面。" },
+            { "word": "left", "phonetic": "/left/", "meaning": "左", "example": "Turn left at the corner.", "exampleMeaning": "在拐角处左转。" },
+            { "word": "right", "phonetic": "/raɪt/", "meaning": "右", "example": "Turn right at the light.", "exampleMeaning": "在红绿灯处右转。" },
+            { "word": "up", "phonetic": "/ʌp/", "meaning": "上", "example": "Look up at the sky.", "exampleMeaning": "抬头看天空。" },
+            { "word": "down", "phonetic": "/daʊn/", "meaning": "下", "example": "Go down the stairs.", "exampleMeaning": "走下楼梯。" },
+            { "word": "top", "phonetic": "/tɑːp/", "meaning": "顶部", "example": "The cat is on top of the table.", "exampleMeaning": "猫在桌子顶部。" },
+            { "word": "bottom", "phonetic": "/ˈbɑːtəm/", "meaning": "底部", "example": "The shoes are at the bottom.", "exampleMeaning": "鞋子在底部。" }
+          ]
+        },
+        {
+          "name": "位置关系",
+          "words": [
+            { "word": "inside", "phonetic": "/ˌɪnˈsaɪd/", "meaning": "里面", "example": "It is warm inside the house.", "exampleMeaning": "房子里面很暖和。" },
+            { "word": "outside", "phonetic": "/ˌaʊtˈsaɪd/", "meaning": "外面", "example": "Let's play outside.", "exampleMeaning": "我们去外面玩吧。" },
+            { "word": "middle", "phonetic": "/ˈmɪdl/", "meaning": "中间", "example": "The ball is in the middle.", "exampleMeaning": "球在中间。" },
+            { "word": "center", "phonetic": "/ˈsentər/", "meaning": "中心", "example": "The statue is at the center.", "exampleMeaning": "雕像在中心。" },
+            { "word": "side", "phonetic": "/saɪd/", "meaning": "旁边", "example": "He sat by my side.", "exampleMeaning": "他坐在我旁边。" },
+            { "word": "near", "phonetic": "/nɪr/", "meaning": "附近", "example": "The school is near my house.", "exampleMeaning": "学校在我家附近。" },
+            { "word": "far", "phonetic": "/fɑːr/", "meaning": "远处", "example": "The mountain is far away.", "exampleMeaning": "山在远处。" },
+            { "word": "opposite", "phonetic": "/ˈɑːpəzɪt/", "meaning": "对面", "example": "The bank is opposite the park.", "exampleMeaning": "银行在公园对面。" }
+          ]
+        }
+      ]
+    },
+    {
+      "id": "places",
+      "name": "场所",
+      "icon": "building.2.fill",
+      "words": [],
+      "subcategories": [
+        {
+          "name": "城市建筑",
+          "words": [
+            { "word": "building", "phonetic": "/ˈbɪldɪŋ/", "meaning": "建筑", "example": "That building is very tall.", "exampleMeaning": "那栋建筑非常高。" },
+            { "word": "office", "phonetic": "/ˈɔːfɪs/", "meaning": "办公室", "example": "I work in an office.", "exampleMeaning": "我在办公室工作。" },
+            { "word": "hospital", "phonetic": "/ˈhɑːspɪtl/", "meaning": "医院", "example": "The hospital is near my house.", "exampleMeaning": "医院在我家附近。" },
+            { "word": "school", "phonetic": "/skuːl/", "meaning": "学校", "example": "The children go to school.", "exampleMeaning": "孩子们去上学。" },
+            { "word": "library", "phonetic": "/ˈlaɪbreri/", "meaning": "图书馆", "example": "I study at the library.", "exampleMeaning": "我在图书馆学习。" },
+            { "word": "museum", "phonetic": "/mjuˈziːəm/", "meaning": "博物馆", "example": "The museum has many old things.", "exampleMeaning": "博物馆有很多古老的东西。" },
+            { "word": "bank", "phonetic": "/bæŋk/", "meaning": "银行", "example": "I need to go to the bank.", "exampleMeaning": "我需要去银行。" },
+            { "word": "supermarket", "phonetic": "/ˈsuːpərmɑːrkɪt/", "meaning": "超市", "example": "I buy food at the supermarket.", "exampleMeaning": "我在超市买食物。" },
+            { "word": "mall", "phonetic": "/mɔːl/", "meaning": "商场", "example": "Let's go shopping at the mall.", "exampleMeaning": "我们去商场购物吧。" },
+            { "word": "restaurant", "phonetic": "/ˈrestərɑːnt/", "meaning": "餐厅", "example": "We had dinner at a restaurant.", "exampleMeaning": "我们在餐厅吃了晚饭。" },
+            { "word": "hotel", "phonetic": "/hoʊˈtel/", "meaning": "酒店", "example": "We stayed at a nice hotel.", "exampleMeaning": "我们住了一家不错的酒店。" },
+            { "word": "cinema", "phonetic": "/ˈsɪnəmə/", "meaning": "电影院", "example": "Let's watch a movie at the cinema.", "exampleMeaning": "我们去电影院看电影吧。" },
+            { "word": "gym", "phonetic": "/dʒɪm/", "meaning": "健身房", "example": "I exercise at the gym.", "exampleMeaning": "我在健身房锻炼。" },
+            { "word": "church", "phonetic": "/tʃɜːrtʃ/", "meaning": "教堂", "example": "The church is very old.", "exampleMeaning": "这座教堂很古老。" },
+            { "word": "factory", "phonetic": "/ˈfæktəri/", "meaning": "工厂", "example": "He works in a factory.", "exampleMeaning": "他在工厂工作。" }
+          ]
+        },
+        {
+          "name": "交通出行",
+          "words": [
+            { "word": "airport", "phonetic": "/ˈerpɔːrt/", "meaning": "机场", "example": "We arrived at the airport early.", "exampleMeaning": "我们早早到了机场。" },
+            { "word": "station", "phonetic": "/ˈsteɪʃn/", "meaning": "车站", "example": "The train station is crowded.", "exampleMeaning": "火车站很拥挤。" },
+            { "word": "bridge", "phonetic": "/brɪdʒ/", "meaning": "桥", "example": "The bridge is very long.", "exampleMeaning": "这座桥很长。" },
+            { "word": "bus stop", "phonetic": "/bʌs stɑːp/", "meaning": "公交站", "example": "I wait at the bus stop.", "exampleMeaning": "我在公交站等车。" },
+            { "word": "port", "phonetic": "/pɔːrt/", "meaning": "港口", "example": "The ship arrived at the port.", "exampleMeaning": "船到港了。" }
+          ]
+        },
+        {
+          "name": "居住户外",
+          "words": [
+            { "word": "house", "phonetic": "/haʊs/", "meaning": "房子", "example": "I live in a big house.", "exampleMeaning": "我住在一所大房子里。" },
+            { "word": "apartment", "phonetic": "/əˈpɑːrtmənt/", "meaning": "公寓", "example": "My apartment is on the 5th floor.", "exampleMeaning": "我的公寓在五楼。" },
+            { "word": "home", "phonetic": "/hoʊm/", "meaning": "家", "example": "I want to go home.", "exampleMeaning": "我想回家。" },
+            { "word": "park", "phonetic": "/pɑːrk/", "meaning": "公园", "example": "We walk in the park.", "exampleMeaning": "我们在公园散步。" },
+            { "word": "square", "phonetic": "/skwer/", "meaning": "广场", "example": "People dance at the square.", "exampleMeaning": "人们在广场跳舞。" },
+            { "word": "garden", "phonetic": "/ˈɡɑːrdn/", "meaning": "花园", "example": "The flowers in the garden are beautiful.", "exampleMeaning": "花园里的花很美。" },
+            { "word": "playground", "phonetic": "/ˈpleɪɡraʊnd/", "meaning": "游乐场", "example": "The kids are at the playground.", "exampleMeaning": "孩子们在游乐场。" },
+            { "word": "market", "phonetic": "/ˈmɑːrkɪt/", "meaning": "市场", "example": "I bought fresh fish at the market.", "exampleMeaning": "我在市场买了新鲜的鱼。" }
+          ]
+        }
+      ]
+    },
+    {
+      "id": "furniture",
+      "name": "家具",
+      "icon": "chair.fill",
+      "words": [],
+      "subcategories": [
+        {
+          "name": "坐卧",
+          "words": [
+            { "word": "sofa", "phonetic": "/ˈsoʊfə/", "meaning": "沙发", "example": "We sit on the sofa.", "exampleMeaning": "我们坐在沙发上。" },
+            { "word": "bed", "phonetic": "/bed/", "meaning": "床", "example": "I go to bed at ten.", "exampleMeaning": "我十点上床睡觉。" },
+            { "word": "chair", "phonetic": "/tʃer/", "meaning": "椅子", "example": "Please sit on the chair.", "exampleMeaning": "请坐在椅子上。" },
+            { "word": "armchair", "phonetic": "/ˈɑːrmtʃer/", "meaning": "扶手椅", "example": "He fell asleep in the armchair.", "exampleMeaning": "他在扶手椅上睡着了。" },
+            { "word": "stool", "phonetic": "/stuːl/", "meaning": "凳子", "example": "The child sits on a stool.", "exampleMeaning": "小孩坐在凳子上。" }
+          ]
+        },
+        {
+          "name": "收纳",
+          "words": [
+            { "word": "wardrobe", "phonetic": "/ˈwɔːrdroʊb/", "meaning": "衣柜", "example": "I hang my clothes in the wardrobe.", "exampleMeaning": "我把衣服挂在衣柜里。" },
+            { "word": "cabinet", "phonetic": "/ˈkæbɪnət/", "meaning": "柜子", "example": "The plates are in the cabinet.", "exampleMeaning": "盘子在柜子里。" },
+            { "word": "bookshelf", "phonetic": "/ˈbʊkʃelf/", "meaning": "书架", "example": "The bookshelf is full of books.", "exampleMeaning": "书架上摆满了书。" },
+            { "word": "dresser", "phonetic": "/ˈdresər/", "meaning": "梳妆台", "example": "She sits at the dresser.", "exampleMeaning": "她坐在梳妆台前。" },
+            { "word": "cupboard", "phonetic": "/ˈkʌbərd/", "meaning": "碗柜", "example": "The cups are in the cupboard.", "exampleMeaning": "杯子在碗柜里。" },
+            { "word": "drawer", "phonetic": "/drɔːr/", "meaning": "抽屉", "example": "The pen is in the drawer.", "exampleMeaning": "笔在抽屉里。" }
+          ]
+        },
+        {
+          "name": "桌台",
+          "words": [
+            { "word": "table", "phonetic": "/ˈteɪbl/", "meaning": "桌子", "example": "The book is on the table.", "exampleMeaning": "书在桌子上。" },
+            { "word": "desk", "phonetic": "/desk/", "meaning": "书桌", "example": "I study at my desk.", "exampleMeaning": "我在书桌前学习。" },
+            { "word": "dining table", "phonetic": "/ˈdaɪnɪŋ ˈteɪbl/", "meaning": "餐桌", "example": "We eat at the dining table.", "exampleMeaning": "我们在餐桌吃饭。" },
+            { "word": "coffee table", "phonetic": "/ˈkɔːfi ˈteɪbl/", "meaning": "茶几", "example": "The magazine is on the coffee table.", "exampleMeaning": "杂志在茶几上。" },
+            { "word": "nightstand", "phonetic": "/ˈnaɪtstænd/", "meaning": "床头柜", "example": "I put my phone on the nightstand.", "exampleMeaning": "我把手机放在床头柜上。" }
+          ]
+        }
       ]
     }
   ]

LearnEnglish/LearnEnglish/Services/WordStore.swift

@@ -28,12 +28,29 @@ final class WordStore {
             let data = try Data(contentsOf: url)
             let decoded = try JSONDecoder().decode(WordBank.self, from: data)
             let categories = decoded.categories.map { category -> WordCategory in
-                guard category.id == "numbers" else { return category }
-                var words = NumberWords.makeWords(atoms: category.words)
-                let extras = category.words.filter { NumberWords.atomNumbers[$0.word] == nil }
-                words.append(contentsOf: extras)
-                return WordCategory(id: category.id, name: category.name, icon: category.icon,
-                                    words: words)
+                var cat = category
+                let source: [Word]
+                if let subs = cat.subcategories, !subs.isEmpty {
+                    source = subs.flatMap { $0.words }
+                } else {
+                    source = cat.words
+                }
+                let tagged: [Word]
+                if category.id == "numbers" {
+                    var words = NumberWords.makeWords(atoms: source)
+                    let extras = source.filter { NumberWords.atomNumbers[$0.word] == nil }
+                    words.append(contentsOf: extras)
+                    tagged = words
+                } else {
+                    tagged = source
+                }
+                let words = tagged.map { word -> Word in
+                    var w = word
+                    w.categoryId = category.id
+                    return w
+                }
+                cat.words = words
+                return cat
             }
             bank = WordBank(version: decoded.version, categories: categories)
         } catch {

LearnEnglish/LearnEnglish/Views/CategoryListViewController.swift

@@ -14,6 +14,12 @@ final class CategoryListViewController: UITableViewController {
     override func viewDidLoad() {
         super.viewDidLoad()
         title = "背单词"
+        navigationItem.rightBarButtonItem = UIBarButtonItem(
+            image: UIImage(systemName: "list.bullet.clipboard"),
+            style: .plain,
+            target: self,
+            action: #selector(showHistory)
+        )
         tableView.register(CategoryCardCell.self, forCellReuseIdentifier: "cell")
         tableView.separatorStyle = .none
         tableView.backgroundColor = .systemBackground
@@ -23,6 +29,10 @@ final class CategoryListViewController: UITableViewController {
         }
     }
 
+    @objc private func showHistory() {
+        navigationController?.pushViewController(HistoryViewController(), animated: true)
+    }
+
     private func showError(_ message: String) {
         let label = UILabel()
         label.text = "词库加载失败\n\(message)"
@@ -53,7 +63,12 @@ final class CategoryListViewController: UITableViewController {
     override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
         Haptics.selection()
         let category = store.categories[indexPath.row]
-        navigationController?.pushViewController(
-            WordListViewController(category: category, colorIndex: indexPath.row), animated: true)
+        if let subs = category.subcategories, !subs.isEmpty {
+            let vc = SubcategoryListViewController(category: category, colorIndex: indexPath.row)
+            navigationController?.pushViewController(vc, animated: true)
+        } else {
+            navigationController?.pushViewController(
+                WordListViewController(category: category, colorIndex: indexPath.row), animated: true)
+        }
     }
 }

LearnEnglish/LearnEnglish/Views/HistoryViewController.swift

@@ -0,0 +1,101 @@
+import UIKit
+
+final class HistoryViewController: UITableViewController {
+    private var sections: [(title: String, items: [LearnedRecord])] = []
+    private var speechObserver: NSObjectProtocol?
+    private let timeFormatter: DateFormatter = {
+        let f = DateFormatter()
+        f.locale = Locale(identifier: "zh_CN")
+        f.dateFormat = "HH:mm:ss"
+        return f
+    }()
+
+    init() {
+        super.init(style: .plain)
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) { fatalError() }
+
+    deinit {
+        if let speechObserver {
+            NotificationCenter.default.removeObserver(speechObserver)
+        }
+    }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        title = "学习记录"
+        navigationItem.largeTitleDisplayMode = .never
+        tableView.register(WordCardCell.self, forCellReuseIdentifier: "cell")
+        tableView.separatorStyle = .none
+        tableView.backgroundColor = .systemBackground
+        tableView.contentInset.top = 8
+
+        speechObserver = NotificationCenter.default.addObserver(
+            forName: SpeechService.speakingDidChangeNotification, object: nil, queue: .main
+        ) { [weak self] _ in
+            for cell in self?.tableView.visibleCells ?? [] {
+                (cell as? WordCardCell)?.updateSpeakerState()
+            }
+        }
+    }
+
+    override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+        sections = LearnedStore.shared.sectioned
+        if sections.isEmpty {
+            let label = UILabel()
+            label.text = "暂无学习记录"
+            label.textAlignment = .center
+            label.textColor = .secondaryLabel
+            label.font = .preferredFont(forTextStyle: .body)
+            let bg = UIView()
+            bg.addSubview(label)
+            label.translatesAutoresizingMaskIntoConstraints = false
+            NSLayoutConstraint.activate([
+                label.centerXAnchor.constraint(equalTo: bg.centerXAnchor),
+                label.centerYAnchor.constraint(equalTo: bg.centerYAnchor)
+            ])
+            tableView.backgroundView = bg
+        } else {
+            tableView.backgroundView = nil
+        }
+        tableView.reloadData()
+    }
+
+    override func numberOfSections(in tableView: UITableView) -> Int {
+        sections.count
+    }
+
+    override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
+        sections[section].title
+    }
+
+    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+        sections[section].items.count
+    }
+
+    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! WordCardCell
+        let record = sections[indexPath.section].items[indexPath.row]
+        let time = timeFormatter.string(from: record.learnedAt)
+        cell.configure(with: record.word, count: record.count, accuracy: record.accuracy, time: time)
+        cell.onSpeak = { word in
+            SpeechService.shared.speak(word.word)
+        }
+        cell.onLearn = { [weak self] word in
+            guard let self else { return }
+            let config = QuizConfig(mode: .spelling, words: [word], isStudyMode: true)
+            navigationController?.pushViewController(QuizViewController(config: config), animated: true)
+        }
+        return cell
+    }
+
+    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
+        Haptics.selection()
+        let record = sections[indexPath.section].items[indexPath.row]
+        let detail = WordDetailViewController(word: record.word, categoryName: "")
+        navigationController?.pushViewController(detail, animated: true)
+    }
+}

LearnEnglish/LearnEnglish/Views/QuizViewController.swift

@@ -52,8 +52,8 @@ final class QuizViewController: UIViewController {
         self.isUppercase = uppercase
         let words = config.words.map { word in
             let text = uppercase ? word.word.uppercased() : word.word.lowercased()
-            return Word(word: text, phonetic: word.phonetic, meaning: word.meaning,
-                        example: word.example, exampleMeaning: word.exampleMeaning)
+            return Word(categoryId: word.categoryId, word: text, phonetic: word.phonetic,
+                        meaning: word.meaning, example: word.example, exampleMeaning: word.exampleMeaning)
         }
         self.questions = QuizGenerator.makeQuestions(mode: config.mode, words: words)
         super.init(nibName: nil, bundle: nil)
@@ -218,6 +218,7 @@ final class QuizViewController: UIViewController {
 
         if isSpelling {
             spellingHintLabel.text = "\(question.word.word.count) 个字母，补全空缺部分"
+            spellingView.isUppercase = isUppercase
             spellingView.configure(blankedWord: question.blankedWord, blankPositions: question.blankPositions)
             if config.isStudyMode {
                 nextButton.isHidden = true
@@ -358,6 +359,7 @@ final class QuizViewController: UIViewController {
         guard selectedOption == nil else { return }
         selectedOption = typed
         let correct = typed.lowercased() == question.answer.lowercased()
+        LearnedStore.shared.record(question.word, correct: correct)
         if !correct {
             wrongWords.append(question.word)
         }
@@ -424,7 +426,9 @@ final class QuizViewController: UIViewController {
         isUppercase.toggle()
         UserDefaults.standard.set(isUppercase, forKey: "spelling_uppercase")
         updateCaseButton()
-        restart()
+        spellingView.isUppercase = isUppercase
+        questions = QuizGenerator.recase(questions, toUpper: isUppercase)
+        spellingView.updateCase(toUpper: isUppercase)
     }
 
     private func updateCaseButton() {
@@ -509,8 +513,8 @@ final class QuizViewController: UIViewController {
         view.subviews.compactMap { $0 as? QuizResultView }.forEach { $0.removeFromSuperview() }
         let words = config.words.map { word in
             let text = isUppercase ? word.word.uppercased() : word.word.lowercased()
-            return Word(word: text, phonetic: word.phonetic, meaning: word.meaning,
-                        example: word.example, exampleMeaning: word.exampleMeaning)
+            return Word(categoryId: word.categoryId, word: text, phonetic: word.phonetic,
+                        meaning: word.meaning, example: word.example, exampleMeaning: word.exampleMeaning)
         }
         questions = QuizGenerator.makeQuestions(mode: config.mode, words: words)
         currentIndex = 0

LearnEnglish/LearnEnglish/Views/SpellingInputView.swift

@@ -17,6 +17,8 @@ final class SpellingInputView: UIView, UITextFieldDelegate {
     private var cursorView: UIView?
     private var inputEnabled = true
 
+    var isUppercase = false
+
     var isComplete: Bool {
         !filledBlanks.isEmpty && filledBlanks.allSatisfy { !$0.isEmpty }
     }
@@ -55,6 +57,7 @@ final class SpellingInputView: UIView, UITextFieldDelegate {
         hiddenField.autocapitalizationType = .none
         hiddenField.spellCheckingType = .no
         hiddenField.keyboardType = .asciiCapable
+        hiddenField.returnKeyType = .done
         hiddenField.frame = .zero
         addSubview(hiddenField)
 
@@ -132,6 +135,20 @@ final class SpellingInputView: UIView, UITextFieldDelegate {
         hiddenField.inputAccessoryView = nil
     }
 
+    func updateCase(toUpper: Bool) {
+        chars = chars.map {
+            guard $0 != "_" else { return $0 }
+            return toUpper ? $0.uppercased() : $0.lowercased()
+        }
+        filledBlanks = filledBlanks.map {
+            $0.isEmpty ? $0 : (toUpper ? $0.uppercased() : $0.lowercased())
+        }
+        for (index, box) in boxViews.enumerated() where chars[index] != "_" {
+            (box.viewWithTag(100) as? UILabel)?.text = chars[index]
+        }
+        refreshBoxes()
+    }
+
     func showResultState(correct: Bool) {
         let color = correct ? Theme.Color.correct : Theme.Color.wrong
         for position in blankPositions {
@@ -168,7 +185,8 @@ final class SpellingInputView: UIView, UITextFieldDelegate {
                 onChange?()
             }
         } else if let char = string.last, char.isLetter, cursorIndex < blankPositions.count {
-            filledBlanks[cursorIndex] = String(char).lowercased()
+            let converted = isUppercase ? char.uppercased() : char.lowercased()
+            filledBlanks[cursorIndex] = converted
             cursorIndex += 1
             refreshBoxes()
             popBox(atBlank: cursorIndex - 1)
@@ -178,6 +196,12 @@ final class SpellingInputView: UIView, UITextFieldDelegate {
         return false
     }
 
+    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
+        guard isComplete else { return false }
+        onSubmit?()
+        return false
+    }
+
     // MARK: - Boxes
 
     private func rebuildBoxes() {

LearnEnglish/LearnEnglish/Views/SubcategoryListViewController.swift

@@ -0,0 +1,50 @@
+import UIKit
+
+final class SubcategoryListViewController: UITableViewController {
+    private let category: WordCategory
+    private let colorIndex: Int
+    private let subcategories: [Subcategory]
+
+    init(category: WordCategory, colorIndex: Int) {
+        self.category = category
+        self.colorIndex = colorIndex
+        self.subcategories = category.subcategories ?? []
+        super.init(style: .plain)
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) { fatalError() }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        title = category.name
+        navigationItem.largeTitleDisplayMode = .never
+        tableView.register(CategoryCardCell.self, forCellReuseIdentifier: "cell")
+        tableView.separatorStyle = .none
+        tableView.backgroundColor = .systemBackground
+        tableView.contentInset.top = 8
+    }
+
+    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+        subcategories.count
+    }
+
+    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! CategoryCardCell
+        let sub = subcategories[indexPath.row]
+        cell.configure(with: makeSynthetic(sub), color: Theme.Color.category(at: colorIndex))
+        return cell
+    }
+
+    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
+        Haptics.selection()
+        let sub = subcategories[indexPath.row]
+        navigationController?.pushViewController(
+            WordListViewController(category: makeSynthetic(sub), colorIndex: colorIndex), animated: true)
+    }
+
+    private func makeSynthetic(_ sub: Subcategory) -> WordCategory {
+        WordCategory(id: sub.name, name: sub.name, icon: category.icon,
+                     words: sub.words, subcategories: nil)
+    }
+}

LearnEnglish/LearnEnglish/Views/WordCardCell.swift

@@ -5,6 +5,7 @@ final class WordCardCell: UITableViewCell {
     private let wordLabel = UILabel()
     private let phoneticLabel = UILabel()
     private let meaningLabel = UILabel()
+    private let countLabel = UILabel()
     private let learnButton = UIButton(type: .system)
     private let speakerButton = UIButton(type: .system)
     private var word: Word?
@@ -37,6 +38,10 @@ final class WordCardCell: UITableViewCell {
         meaningLabel.font = .preferredFont(forTextStyle: .subheadline)
         meaningLabel.textColor = .secondaryLabel
 
+        countLabel.font = .preferredFont(forTextStyle: .caption2)
+        countLabel.textColor = Theme.Color.accent
+        countLabel.setContentHuggingPriority(.required, for: .horizontal)
+
         let textStack = UIStackView(arrangedSubviews: [wordLabel, phoneticLabel, meaningLabel])
         textStack.axis = .vertical
         textStack.spacing = 8
@@ -57,7 +62,7 @@ final class WordCardCell: UITableViewCell {
         }, for: .touchUpInside)
         speakerButton.setContentHuggingPriority(.required, for: .horizontal)
 
-        let row = UIStackView(arrangedSubviews: [textStack, learnButton, speakerButton])
+        let row = UIStackView(arrangedSubviews: [textStack, countLabel, learnButton, speakerButton])
         row.axis = .horizontal
         row.alignment = .center
         row.spacing = 8
@@ -83,9 +88,16 @@ final class WordCardCell: UITableViewCell {
         wordLabel.text = word.word
         phoneticLabel.text = word.phonetic
         meaningLabel.text = word.meaning
+        countLabel.isHidden = true
         updateSpeakerState()
     }
 
+    func configure(with word: Word, count: Int, accuracy: Int, time: String) {
+        configure(with: word)
+        countLabel.text = "\(time) · \(count)次 · \(accuracy)%"
+        countLabel.isHidden = false
+    }
+
     func updateSpeakerState() {
         guard let word else { return }
         let speaking = SpeechService.shared.isSpeaking(word.word)

LearnEnglish/LearnEnglish/Views/WordDetailViewController.swift

@@ -31,7 +31,10 @@ final class WordDetailViewController: UIViewController {
         view.backgroundColor = .systemBackground
         title = categoryName
         navigationItem.largeTitleDisplayMode = .never
-        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "学习", style: .plain, target: self, action: #selector(startSpelling))
+        navigationItem.rightBarButtonItems = [
+            UIBarButtonItem(title: "学习", style: .plain, target: self, action: #selector(startSpelling)),
+            UIBarButtonItem(image: UIImage(systemName: "clock.arrow.circlepath"), style: .plain, target: self, action: #selector(showHistory))
+        ]
         buildLayout()
         updateSpeakState()
         speechObserver = NotificationCenter.default.addObserver(
@@ -187,6 +190,10 @@ final class WordDetailViewController: UIViewController {
         return card
     }
 
+    @objc private func showHistory() {
+        navigationController?.pushViewController(WordHistoryViewController(word: word), animated: true)
+    }
+
     @objc private func startSpelling() {
         Haptics.selection()
         let config = QuizConfig(mode: .spelling, words: [word], isStudyMode: true)

LearnEnglish/LearnEnglish/Views/WordHistoryViewController.swift

@@ -0,0 +1,146 @@
+import UIKit
+
+final class WordHistoryViewController: UIViewController {
+    private let word: Word
+    private let record: LearnedRecord?
+
+    init(word: Word) {
+        self.word = word
+        record = LearnedStore.shared.record(for: word)
+        super.init(nibName: nil, bundle: nil)
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) { fatalError() }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        title = "学习记录"
+        navigationItem.largeTitleDisplayMode = .never
+        view.backgroundColor = .systemBackground
+        buildLayout()
+    }
+
+    private func buildLayout() {
+        guard let record else {
+            let label = UILabel()
+            label.text = "暂无学习记录"
+            label.textAlignment = .center
+            label.textColor = .secondaryLabel
+            label.font = .preferredFont(forTextStyle: .body)
+            view.addSubview(label)
+            label.translatesAutoresizingMaskIntoConstraints = false
+            NSLayoutConstraint.activate([
+                label.centerXAnchor.constraint(equalTo: view.centerXAnchor),
+                label.centerYAnchor.constraint(equalTo: view.centerYAnchor)
+            ])
+            return
+        }
+
+        let wordCard = makeWordCard(record)
+        let statsCard = makeStatsCard(record)
+
+        let stack = UIStackView(arrangedSubviews: [wordCard, statsCard])
+        stack.axis = .vertical
+        stack.spacing = 20
+
+        let scrollView = UIScrollView()
+        scrollView.alwaysBounceVertical = true
+        view.addSubview(scrollView)
+        scrollView.addSubview(stack)
+        scrollView.translatesAutoresizingMaskIntoConstraints = false
+        stack.translatesAutoresizingMaskIntoConstraints = false
+        NSLayoutConstraint.activate([
+            scrollView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
+            scrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
+            scrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
+            scrollView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
+            stack.topAnchor.constraint(equalTo: scrollView.contentLayoutGuide.topAnchor, constant: 20),
+            stack.leadingAnchor.constraint(equalTo: scrollView.contentLayoutGuide.leadingAnchor, constant: 16),
+            stack.trailingAnchor.constraint(equalTo: scrollView.contentLayoutGuide.trailingAnchor, constant: -16),
+            stack.bottomAnchor.constraint(equalTo: scrollView.contentLayoutGuide.bottomAnchor, constant: -16),
+            stack.widthAnchor.constraint(equalTo: scrollView.frameLayoutGuide.widthAnchor, constant: -32)
+        ])
+    }
+
+    private func makeWordCard(_ record: LearnedRecord) -> UIView {
+        let card = UIView()
+        card.backgroundColor = Theme.Color.cardBackground
+        card.layer.cornerRadius = Theme.Metrics.cardRadius
+
+        let wordLabel = UILabel()
+        wordLabel.text = record.word.word
+        wordLabel.font = .preferredFont(forTextStyle: .headline)
+
+        let phoneticLabel = UILabel()
+        phoneticLabel.text = record.word.phonetic
+        phoneticLabel.font = .preferredFont(forTextStyle: .caption1)
+        phoneticLabel.textColor = .secondaryLabel
+
+        let meaningLabel = UILabel()
+        meaningLabel.text = record.word.meaning
+        meaningLabel.font = .preferredFont(forTextStyle: .subheadline)
+        meaningLabel.textColor = .secondaryLabel
+
+        let textStack = UIStackView(arrangedSubviews: [wordLabel, phoneticLabel, meaningLabel])
+        textStack.axis = .vertical
+        textStack.spacing = 8
+
+        card.addSubview(textStack)
+        textStack.translatesAutoresizingMaskIntoConstraints = false
+        NSLayoutConstraint.activate([
+            textStack.topAnchor.constraint(equalTo: card.topAnchor, constant: 14),
+            textStack.leadingAnchor.constraint(equalTo: card.leadingAnchor, constant: 14),
+            textStack.trailingAnchor.constraint(equalTo: card.trailingAnchor, constant: -14),
+            textStack.bottomAnchor.constraint(equalTo: card.bottomAnchor, constant: -14)
+        ])
+        return card
+    }
+
+    private func makeStatsCard(_ record: LearnedRecord) -> UIView {
+        let card = UIView()
+        card.backgroundColor = Theme.Color.cardBackground
+        card.layer.cornerRadius = Theme.Metrics.cardRadius
+
+        let title = UILabel()
+        title.text = "学习统计"
+        title.font = .preferredFont(forTextStyle: .caption1)
+        title.textColor = .secondaryLabel
+
+        let countLabel = UILabel()
+        countLabel.text = "\(record.count) 次"
+        countLabel.font = .systemFont(ofSize: 36, weight: .bold)
+
+        let accuracyLabel = UILabel()
+        accuracyLabel.text = "正确率 \(record.accuracy)%"
+        accuracyLabel.font = .preferredFont(forTextStyle: .subheadline)
+        accuracyLabel.textColor = Theme.Color.correct
+
+        let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "zh_CN")
+        formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
+        let dateLabel = UILabel()
+        dateLabel.text = "最近学习：\(formatter.string(from: record.learnedAt))"
+        dateLabel.font = .preferredFont(forTextStyle: .caption1)
+        dateLabel.textColor = .tertiaryLabel
+
+        let statsStack = UIStackView(arrangedSubviews: [countLabel, accuracyLabel])
+        statsStack.axis = .horizontal
+        statsStack.spacing = 16
+        statsStack.alignment = .lastBaseline
+
+        let stack = UIStackView(arrangedSubviews: [title, statsStack, dateLabel])
+        stack.axis = .vertical
+        stack.spacing = 12
+
+        card.addSubview(stack)
+        stack.translatesAutoresizingMaskIntoConstraints = false
+        NSLayoutConstraint.activate([
+            stack.topAnchor.constraint(equalTo: card.topAnchor, constant: 16),
+            stack.leadingAnchor.constraint(equalTo: card.leadingAnchor, constant: 16),
+            stack.trailingAnchor.constraint(equalTo: card.trailingAnchor, constant: -16),
+            stack.bottomAnchor.constraint(equalTo: card.bottomAnchor, constant: -16)
+        ])
+        return card
+    }
+}

LearnEnglish/LearnEnglish/Views/WordListViewController.swift

@@ -3,14 +3,22 @@ import UIKit
 final class WordListViewController: UIViewController {
     private let category: WordCategory
     private let colorIndex: Int
+    private var words: [Word]
+    private var subcategories: [Subcategory]?
     private let tableView = UITableView(frame: .zero, style: .plain)
     private let ctaBackground = UIVisualEffectView(effect: UIBlurEffect(style: .systemMaterial))
     private let quizButton = UIButton(type: .system)
     private var speechObserver: NSObjectProtocol?
 
+    private var displaySubcategories: [Subcategory]? {
+        subcategories.flatMap { $0.isEmpty ? nil : $0 }
+    }
+
     init(category: WordCategory, colorIndex: Int) {
         self.category = category
         self.colorIndex = colorIndex
+        self.words = category.words
+        self.subcategories = category.subcategories
         super.init(nibName: nil, bundle: nil)
     }
 
@@ -27,6 +35,12 @@ final class WordListViewController: UIViewController {
         super.viewDidLoad()
         title = category.name
         navigationItem.largeTitleDisplayMode = .never
+        navigationItem.rightBarButtonItem = UIBarButtonItem(
+            image: UIImage(systemName: "arrow.triangle.2.circlepath"),
+            style: .plain,
+            target: self,
+            action: #selector(shuffleWords)
+        )
         view.backgroundColor = .systemBackground
 
         tableView.dataSource = self
@@ -119,16 +133,41 @@ final class WordListViewController: UIViewController {
 
     private func startQuiz() {
         Haptics.selection()
-        let words: [Word]
+        let quizWords: [Word]
         if category.id == "numbers" {
-            words = NumberWords.randomWords(count: 50)
+            quizWords = NumberWords.randomWords(count: 50)
         } else {
-            words = category.words
+            quizWords = words
         }
-        let request = QuizSetupRequest(words: words)
+        let request = QuizSetupRequest(words: quizWords)
         navigationController?.pushViewController(QuizSetupViewController(request: request), animated: true)
     }
 
+    @objc private func shuffleWords() {
+        Haptics.selection()
+        if var subs = subcategories {
+            subs = subs.shuffled().map { sub in
+                var s = sub
+                s.words = sub.words.shuffled()
+                return s
+            }
+            subcategories = subs
+        } else {
+            words.shuffle()
+        }
+        tableView.reloadData()
+        let cells = tableView.visibleCells
+        for (i, cell) in cells.enumerated() {
+            cell.alpha = 0
+            cell.transform = CGAffineTransform(translationX: 0, y: 12)
+            UIView.animate(withDuration: 0.3, delay: Double(i) * 0.03,
+                           options: [.curveEaseOut, .allowUserInteraction]) {
+                cell.alpha = 1
+                cell.transform = .identity
+            }
+        }
+    }
+
     private func updateVisibleSpeakers() {
         for cell in tableView.visibleCells.compactMap({ $0 as? WordCardCell }) {
             cell.updateSpeakerState()
@@ -137,13 +176,29 @@ final class WordListViewController: UIViewController {
 }
 
 extension WordListViewController: UITableViewDataSource, UITableViewDelegate {
+    func numberOfSections(in tableView: UITableView) -> Int {
+        displaySubcategories?.count ?? 1
+    }
+
+    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
+        displaySubcategories?[section].name
+    }
+
     func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        category.words.count
+        if let subs = displaySubcategories {
+            return subs[section].words.count
+        }
+        return words.count
     }
 
     func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
         let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! WordCardCell
-        let word = category.words[indexPath.row]
+        let word: Word
+        if let subs = displaySubcategories {
+            word = subs[indexPath.section].words[indexPath.row]
+        } else {
+            word = words[indexPath.row]
+        }
         cell.configure(with: word)
         cell.onSpeak = { word in
             SpeechService.shared.speak(word.word)
@@ -158,7 +213,13 @@ extension WordListViewController: UITableViewDataSource, UITableViewDelegate {
 
     func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
         Haptics.selection()
-        let detail = WordDetailViewController(word: category.words[indexPath.row], categoryName: category.name)
+        let word: Word
+        if let subs = displaySubcategories {
+            word = subs[indexPath.section].words[indexPath.row]
+        } else {
+            word = words[indexPath.row]
+        }
+        let detail = WordDetailViewController(word: word, categoryName: category.name)
         navigationController?.pushViewController(detail, animated: true)
     }
 }