整个课程和数据UI重新设计版本

kouyu_english/lib/core/models.dart

@@ -2,13 +2,14 @@ enum LearningGoal { dailyLife, travel, workStarter }
 
 enum PlacementLevel { beginner, someBasics, simpleConversation }
 
-enum AppTab { home, learn, dialogue, review, progress }
+enum AppTab { learn, dialogue, review, profile }
 
 enum LessonStep {
   preview,
   listening,
   speaking,
   reading,
+  material,
   writing,
   dialogue,
   independent,
@@ -183,6 +184,15 @@ class VocabularyItem {
     this.ipa,
   });
 
+  factory VocabularyItem.fromJson(Map<String, dynamic> json) => VocabularyItem(
+    id: json['id'] as String,
+    word: json['word'] as String,
+    meaning: json['meaning'] as String,
+    example: json['example'] as String? ?? '',
+    exampleMeaning: json['exampleMeaning'] as String? ?? '',
+    ipa: json['ipa'] as String?,
+  );
+
   final String id;
   final String word;
   final String meaning;
@@ -395,11 +405,7 @@ class DialogueTurn {
   final bool isLearner;
   final String? translation;
 
-  DialogueTurn copyWith({
-    String? text,
-    bool? isLearner,
-    String? translation,
-  }) {
+  DialogueTurn copyWith({String? text, bool? isLearner, String? translation}) {
     return DialogueTurn(
       text: text ?? this.text,
       isLearner: isLearner ?? this.isLearner,