body {
      font-family: Arial, sans-serif;
      padding: 20px;
    }
    .container {
      max-width: 400px;
      margin: auto;
      padding: 20px;
      border: 1px solid #ccc;
      border-radius: 8px;
      background: #f9f9f9;
    }
    .output {
      margin-top: 20px;
      padding: 15px;
      border: 1px solid #666;
      background: #fff;
      border-radius: 8px;
    }