* {
    box-sizing: border-box;
  }
  body {
    margin: 0;
    background: #f5f7fa;
    font-family: 'Poppins', sans-serif;
    color: #333;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }
  h1 {
    margin-bottom: 8px;
    font-weight: 600;
    color: #222;
  }
  h2 {
    margin-bottom: 8px;
    font-weight: 600;
    color: #222;
  }
  p {
    margin-top: 0;
    margin-bottom: 16px;
    color: #555;
  }
  input, select {
    font-family: 'Poppins', sans-serif;
    font-size: 1rem;
  }

  /* Container */
  .container {
    
    margin: 20px auto 40px;
    background: #fff;
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    border-radius: 8px;
    overflow: hidden;
  }

  /* Layout - desktop side by side */
  .checkout-wrapper {
    display: flex;
    flex-direction: row;
    gap: 20px;
  }

  /* Form and summary */
  .checkout-form {
    flex: 2;
    padding: 24px 32px;
    border-right: 1px solid #eee;
  }

  .order-summary {
    flex: 1;
    background: #f9fafb;
    padding: 24px 24px;
  }

  /* Sections */
  .section {
    margin-bottom: 32px;
  }

  label {
    display: block;
    font-weight: 600;
    margin-bottom: 6px;
    color: #444;
  }
  input[type="text"],
  input[type="email"],
  input[type="tel"],
  input[type="number"],
  select {
    width: 100%;
    padding: 10px 12px;
    border: 1.5px solid #ddd;
    border-radius: 6px;
    transition: border-color 0.3s ease;
  }
  input[type="text"]:focus,
  input[type="email"]:focus,
  input[type="tel"]:focus,
  input[type="number"]:focus,
  select:focus {
    outline: none;
    border-color: #4a90e2;
    box-shadow: 0 0 6px rgba(74,144,226,0.3);
  }

  /* Input row for two inputs side by side */
  .input-row {
    display: flex;
    gap: 16px;
  }
  .input-row .input-group {
    flex: 1;
  }

  /* Payment radio buttons */
  .payment-methods {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
  }
  .payment-method {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-weight: 600;
    user-select: none;
  }
  .payment-method input[type="radio"] {
    accent-color: #4a90e2;
    cursor: pointer;
  }
  .payment-method input[type="radio"]:disabled + span {
    color: #aaa;
    cursor: default;
  }

  /* Hide all payment detail sections by default */
  .payment-details {
    display: none;
    margin-top: 12px;
  }

  /* Show active payment details */
  .payment-details.active {
    display: block;
  }

  /* Summary */
  .summary-title {
    font-weight: 700;
    margin-bottom: 16px;
    font-size: 1.1rem;
  }
  .summary-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 12px;
    font-size: 0.95rem;
    color: #555;
  }
  .summary-item.total {
    font-weight: 700;
    font-size: 1.15rem;
    border-top: 1.5px solid #ddd;
    padding-top: 12px;
    color: #222;
  }

  /* Place order button */
  button.place-order {
    width: 100%;
    padding: 14px 0;
    background: #4a90e2;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 700;
    color: white;
    cursor: pointer;
    transition: background 0.3s ease;
  }
  button.place-order:hover:enabled {
    background: #357abd;
  }
  button.place-order:disabled {
    background: #9ebcde;
    cursor: not-allowed;
  }

  /* Footer small note */
  .footer-note {
    text-align: center;
    font-size: 0.85rem;
    color: #999;
    margin-top: 10px;
  }

  /* Responsive mobile */
  @media (max-width: 700px) {
    .checkout-wrapper {
      flex-direction: column;
    }
    .checkout-form {
      border-right: none;
      padding: 24px 20px;
    }
    .order-summary {
      padding: 24px 20px 32px;
      margin-top: 20px;
    }
  }

  /* Mobile screen fit max 350w x 600h */
  @media (max-width: 400px) {
    .container {
      margin: 8px;
      box-shadow: none;
      border-radius: 0;
      max-width: 100vw;
    }
    .checkout-form, .order-summary {
      padding-left: 12px;
      padding-right: 12px;
    }
    h2 {
      font-size: 1.4rem;
    }
  }