*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

    :root {
      --primary: #008060;
      --primary-hover: #006e52;
      --primary-light: #e6f2ee;
      --text: #202223;
      --text-muted: #6d7175;
      --border: #d1d3d5;
      --border-light: #e4e5e7;
      --bg: #ffffff;
      --white: #ffffff;
      --error: #d82c0d;
      --success: #008060;
      --radius: 8px;
      --radius-sm: 4px;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Helvetica, Arial, sans-serif;
      background: var(--bg);
      color: var(--text);
      line-height: 1.5;
      min-height: 100vh;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    /* Banner */
    .checkout-banner {
      width: 100%;
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
    }
    .checkout-banner img {
      width: 100%;
      height: auto;
      display: block;
    }

    /* Countdown Timer */
    .countdown-timer {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      padding: 6px 16px;
      background: #fff0f0;
      border-bottom: 1px solid #ffdcdc;
      font-size: 0.8rem;
      flex-wrap: wrap;
    }
    .countdown-time {
      font-weight: 700;
      color: #c42121;
      font-variant-numeric: tabular-nums;
      font-size: 1rem;
    }
    .countdown-timer.expired {
      background: #f0f0f0;
    }
    .countdown-timer.expired .countdown-time {
      color: #666;
    }

    /* Main Container */
    .checkout-container {
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }

    @media (min-width: 768px) {
      .checkout-container {
        flex-direction: row;
      }
    }

    /* Left - Form */
    .checkout-form-section {
      flex: 1;
      padding: 20px 16px;
      max-width: 100%;
    }

    @media (min-width: 768px) {
      .checkout-form-section {
        padding: 18px 40px;
        max-width: calc(100% - 380px);
        border-right: 1px solid var(--border);
      }
    }

    @media (min-width: 1024px) {
      .checkout-form-section {
        max-width: 58%;
        min-width: 500px;
      }
    }

    /* Right - Summary */
    .checkout-summary {
      background: var(--white);
      order: -1;
      border-bottom: 1px solid var(--border);
    }

    /* Mobile Collapsible Summary */
    .summary-toggle {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 16px;
      cursor: pointer;
      background: var(--white);
      -webkit-tap-highlight-color: transparent;
    }

    .summary-toggle-left {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--primary);
    }

    .summary-toggle-left svg {
      width: 20px;
      height: 20px;
      transition: transform 0.3s;
    }

    .summary-toggle-right {
      font-weight: 700;
      font-size: 1rem;
      color: var(--text);
    }

    .summary-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
    }

    .summary-content.expanded {
      max-height: 600px;
    }

    .summary-content-inner {
      padding: 0 16px 20px;
    }

    .summary-toggle[aria-expanded="true"] .summary-toggle-left svg {
      transform: rotate(180deg);
    }

    @media (min-width: 768px) {
      .checkout-summary {
        padding: 32px 24px;
        width: 380px;
        min-width: 320px;
        max-width: 420px;
        order: 0;
        border-bottom: none;
        border-left: 1px solid var(--border);
        position: sticky;
        top: 0;
        height: 100vh;
        overflow-y: auto;
      }

      .summary-toggle {
        display: none;
      }

      .summary-content {
        max-height: none !important;
        overflow: visible;
      }

      .summary-content-inner {
        padding: 0;
      }
    }

    /* Header */
    .checkout-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding-bottom: 6px;
      margin-bottom: 10px;
      border-bottom: 1px solid var(--border);
      flex-wrap: wrap;
      gap: 4px;
    }

    .checkout-logo {
      font-size: 1.2rem;
      font-weight: 700;
      color: var(--text);
      text-decoration: none;
      letter-spacing: -0.5px;
    }

    @media (max-width: 480px) {
      .checkout-logo {
        font-size: 1rem;
      }
    }

    .checkout-breadcrumb {
      font-size: 0.75rem;
      color: var(--text-muted);
      white-space: nowrap;
    }

    .checkout-breadcrumb svg {
      width: 14px;
      height: 14px;
      vertical-align: middle;
      margin: 0 4px;
    }

    /* Product Card */
    .summary-product {
      display: flex;
      gap: 12px;
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
    }

    .summary-product-image {
      width: 60px;
      height: 60px;
      background: var(--bg);
      border: 1px solid var(--border);
      border-radius: var(--radius-sm);
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
    }
    .summary-product-image img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .summary-product-details {
      flex: 1;
      min-width: 0;
    }

    .summary-product-name {
      font-weight: 600;
      font-size: 0.9rem;
      margin-bottom: 2px;
      word-break: break-word;
    }

    .summary-product-variant {
      font-size: 0.75rem;
      color: var(--text-muted);
    }

    .summary-product-price {
      font-weight: 600;
      font-size: 0.9rem;
      text-align: right;
      white-space: nowrap;
    }

    /* Totals */
    .order-totals {
      padding: 12px 0;
    }

    .order-line {
      display: flex;
      justify-content: space-between;
      padding: 6px 0;
      font-size: 0.85rem;
    }

    .order-line.total {
      border-top: 1px solid var(--border);
      margin-top: 8px;
      padding-top: 12px;
      font-weight: 700;
      font-size: 1rem;
    }

    /* Payment Section */
    .form-section {
      margin-bottom: 12px;
    }

    .form-section-title {
      font-size: 0.9rem;
      font-weight: 600;
      margin-bottom: 6px;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .form-section-title svg {
      width: 16px;
      height: 16px;
      color: var(--primary);
      flex-shrink: 0;
    }

    /* Guarantee Section */
    .guarantee-section {
      display: flex;
      align-items: center;
      gap: 16px;
      padding: 16px;
      background: linear-gradient(135deg, #e6f2ee 0%, #f0f7f5 100%);
      border: 1px solid var(--primary);
      border-radius: var(--radius);
      margin-top: 20px;
    }

    .guarantee-badge {
      width: 80px;
      height: 80px;
      flex-shrink: 0;
      background: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 100%);
      border-radius: 50%;
      padding: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(0, 128, 96, 0.15);
    }

    .guarantee-badge-img {
      width: 100%;
      height: 100%;
      object-fit: contain;
    }

    .guarantee-content {
      flex: 1;
    }

    .guarantee-title {
      font-size: 0.8rem;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 6px;
      letter-spacing: 0.5px;
    }

    .guarantee-text {
      font-size: 0.75rem;
      color: var(--text-muted);
      line-height: 1.5;
    }

    @media (max-width: 480px) {
      .guarantee-section {
        flex-direction: column;
        text-align: center;
        gap: 12px;
      }
      .guarantee-badge {
        width: 70px;
        height: 70px;
        padding: 10px;
      }
    }

    /* Reviews Section */
    .reviews-section {
      background: var(--white);
      padding: 20px 16px;
      border-top: 1px solid var(--border-light);
      border-bottom: 1px solid var(--border-light);
      margin-top: 20px;
    }

    .rating-widget {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      flex-wrap: nowrap;
      margin-bottom: 20px;
      padding: 10px 12px;
      background: #f8f9fa;
      border-radius: var(--radius);
      overflow: hidden;
    }

    .rating-badge {
      background: #4a7c59;
      color: white;
      padding: 4px 8px;
      border-radius: 4px;
      font-weight: 700;
      font-size: 1rem;
      white-space: nowrap;
      flex-shrink: 0;
    }

    .rating-label {
      font-weight: 700;
      font-size: 0.9rem;
      color: var(--text);
      white-space: nowrap;
      flex-shrink: 0;
    }

    .rating-stars {
      display: flex;
      gap: 1px;
      flex-shrink: 0;
    }

    .rating-stars svg {
      width: 16px;
      height: 16px;
      color: #ffc107;
      fill: #ffc107;
    }

    .rating-count {
      font-size: 0.8rem;
      color: var(--text-muted);
      white-space: nowrap;
      flex-shrink: 0;
    }

    .review-cards {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .review-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 16px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    }

    .reviewer-info {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 8px;
    }

    .reviewer-avatar {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 600;
      font-size: 0.85rem;
    }

    .reviewer-name {
      font-weight: 600;
      font-size: 0.95rem;
      color: var(--text);
    }

    .review-stars {
      display: flex;
      gap: 2px;
      margin-bottom: 8px;
    }

    .review-stars svg {
      width: 16px;
      height: 16px;
      color: #ffc107;
      fill: #ffc107;
    }

    .review-text {
      font-size: 0.85rem;
      color: var(--text-muted);
      line-height: 1.5;
      font-style: italic;
    }

    /* Security Badge */
    .secure-badge {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
      font-size: 0.7rem;
      color: var(--text-muted);
      margin-top: 4px;
      padding: 4px;
      flex-wrap: wrap;
    }

    .secure-badge svg {
      width: 12px;
      height: 12px;
      flex-shrink: 0;
    }

    /* Link styling */
    a {
      color: var(--primary);
      text-decoration: none;
    }
    a:hover {
      text-decoration: underline;
    }

    html, body {
      overflow-x: hidden;
      max-width: 100vw;
    }

    /* Error Alert */
    .error-alert {
      background: #fff0f0;
      border: 1px solid #ffdcdc;
      border-radius: var(--radius-sm);
      padding: 12px 14px;
      margin-bottom: 16px;
      font-size: 0.85rem;
      color: var(--error);
      display: none;
    }

    .error-alert.show {
      display: block;
    }