<!DOCTYPE html>
<html lang="zh-CN">
<head>
  <meta charset="UTF-8">
  <title>测试</title>
</head>
<body>
  <script>
    // 测试数据加载
    console.log('Testing data loading...');
    const stored = localStorage.getItem('learningCategories');
    console.log('Stored data:', stored);
    
    if (stored && stored !== 'null' && stored !== 'undefined') {
      const data = JSON.parse(stored);
      console.log('Parsed data:', data);
      console.log('Data length:', data.length);
      console.log('First item:', data[0]);
    } else {
      console.log('No stored data found');
    }
  </script>
</body>
</html>