body {
      font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
      margin: 0;
      background: #f0f2f5;
      color: #333;
      overflow-y: scroll;
    }
   
    main {
      max-width: 960px;
      margin: auto;
      padding: 0rem 1rem;
      background: white;
    }
    h2 {
      color: #003366;
      border-bottom: 2px solid #ccc;
      padding-bottom: 0.5rem;
      margin-top: 2rem;
    }
    ul {
      padding-left: 1.2rem;
    }