body {
      font-family: Arial, sans-serif;
      background-color: #f4f4f9;
      margin: 0;
      padding: 20px;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 100vh;
    }

    .form-container {
      background: #fff;
      padding: 25px;
      border-radius: 10px;
      width: 100%;
      max-width: 450px;
      box-shadow: 0px 0px 12px rgba(0, 0, 0, 0.1);
    }

    h2 {
      text-align: center;
      margin-bottom: 25px;
      font-size: 1.5rem;
    }

    .form-group {
      margin-bottom: 18px;
    }

    .form-group label {
      display: block;
      margin-bottom: 6px;
      font-weight: bold;
      color: #333;
    }

    .form-group input,
    .form-group select {
      width: 100%;
      padding: 10px;
      border: 1px solid #ccc;
      border-radius: 6px;
      font-size: 1rem;
    }

    #payBtn {
      background-color: #5a67d8;
      color: white;
      border: none;
      padding: 12px;
      border-radius: 6px;
      font-size: 1rem;
      width: 100%;
      cursor: pointer;
      transition: background 0.3s ease;
    }

    #payBtn:hover {
      background-color: #4c51bf;
    }

    @media (max-width: 480px) {
      body {
        padding: 10px;
      }

      h2 {
        font-size: 1.3rem;
      }

      .form-container {
        padding: 15px;
      }

      .form-group input,
      .form-group select,
      #payBtn {
        font-size: 0.95rem;
        padding: 10px;
      }
    }