feat: 添加星星標記使用說明

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/app/generate/page.tsx

@@ -247,7 +247,18 @@ function GenerateContent() {
       <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
         {!showAnalysisView ? (
           <div className="max-w-4xl mx-auto">
-            <h1 className="text-3xl font-bold mb-8">AI 智能生成詞卡</h1>
+            <h1 className="text-3xl font-bold mb-4">AI 智能生成詞卡</h1>
+
+            {/* 星星標記說明 */}
+            <div className="bg-blue-50 border border-blue-200 rounded-lg p-4 mb-6">
+              <div className="flex items-center gap-2 text-sm text-blue-800">
+                <span className="text-yellow-500 text-lg">⭐</span>
+                <span className="font-medium">星星標記說明：</span>
+                標有星星的詞彙和慣用語代表
+                <strong className="text-blue-900">常用、高頻詞彙</strong>
+                ，建議優先學習！
+              </div>
+            </div>
 
             {/* Content Input */}
             <div className="bg-white rounded-xl shadow-sm p-4 sm:p-6 mb-6">