body {
      margin: 0;
      padding: 0;
      font-family: sans-serif;
      background-color: #f0f0f0;
      display: flex;
      justify-content: center;
      align-items: center;
      height: 100vh;
    }

    .card-container {
      display: flex;
      gap: 20px;
    }

    .card {
      width: 150px;
      height: 200px;
      border-radius: 12px;
      box-shadow: 0 4px 8px rgba(0,0,0,0.1);
      display: flex;
      justify-content: center;
      align-items: center;
      color: white;
      font-size: 1.2rem;
      font-weight: bold;
    }

    .blue {
      background-color: #007bff;
    }

    .red {
      background-color: #dc3545;
    }

    .green {
      background-color: #28a745;
    }