/* Product Detail Section */
    .product-detail-section {
      padding: 80px 0;
      background: linear-gradient(145deg, #1c1c1c, #2a2a2a); /* Dark grayscale gradient */
      color: #ffffff;
      min-height: 100vh;
    }

    .product-hero {
      background: linear-gradient(145deg, #2a2a2a, #3a3a3a); /* Slightly lighter grayscale gradient */
      border-radius: 15px;
      padding: 40px;
      margin-bottom: 40px;
      box-shadow: 0 6px 20px rgba(0, 0, 0, 0.6);
      position: relative;
      overflow: hidden;
    }

    .product-badge {
      display: inline-block;
      background: #666666; /* Gray badge */
      color: #ffffff;
      padding: 8px 20px;
      border-radius: 2rem;
      font-size: 1rem;
      font-weight: 600;
      margin-bottom: 1.5rem;
      text-transform: uppercase;
    }

    .product-title {
      font-size: 3rem;
      font-weight: 700;
      color: #ffffff;
      margin-bottom: 0.5rem;
      text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    }

    .product-subtitle {
      font-size: 1.5rem;
      color: #b0b0b0; /* Medium gray */
      font-style: italic;
      margin-bottom: 1.5rem;
    }

    .product-meta {
      font-size: 1rem;
      color: #b0b0b0;
      display: flex;
      gap: 20px;
      justify-content: center;
      margin-bottom: 1rem;
    }

    .product-meta i {
      color: #cccccc; /* Light gray */
      margin-right: 8px;
    }

    .product-image-container {
      text-align: center;
    }

    .product-hero-image {
      max-width: 100%;
      height: auto;
      border-radius: 15px;
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
      transition: transform 0.3s ease;
    }

    .product-hero-image:hover {
      transform: scale(1.05);
    }

    .placeholder-image {
      width: 100%;
      height: 250px;
      background: #333333; /* Dark gray background */
      display: flex;
      align-items: center;
      justify-content: center;
      color: #b0b0b0;
      font-size: 2.5rem;
      border-radius: 15px;
      border: 2px solid #666666; /* Gray border */
    }

    .product-content-card {
      background: linear-gradient(145deg, #2a2a2a, #3a3a3a); /* Grayscale gradient */
      border-radius: 15px;
      padding: 30px;
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
      margin-bottom: 30px;
    }

    .section-title {
      font-size: 2rem;
      font-weight: 600;
      color: #ffffff;
      margin-bottom: 1.5rem;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .section-title i {
      color: #cccccc; /* Light gray */
    }

    .info-grid, .highlights-grid {
      display: grid;
      gap: 1.5rem;
    }

    .info-item, .highlight-item {
      font-size: 1rem;
      color: #b0b0b0;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .highlight-item i {
      color: #cccccc;
    }

    .description-content {
      color: #b0b0b0;
      font-size: 1rem;
      line-height: 1.6;
    }

    .description-content p {
      margin-bottom: 1rem;
    }

    .product-sidebar {
      position: sticky;
      top: 100px;
    }

    .purchase-card {
      background: linear-gradient(145deg, #2a2a2a, #3a3a3a); /* Grayscale gradient */
      border: 2px solid #666666; /* Gray border */
      border-radius: 15px;
      padding: 25px;
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
      margin-bottom: 25px;
    }

    .price-section {
      text-align: center;
      margin-bottom: 1.5rem;
    }

    .price-label {
      font-size: 1.1rem;
      color: #b0b0b0;
      text-transform: uppercase;
    }

    .price-amount {
      font-size: 2.5rem;
      font-weight: 700;
      color: #cccccc; /* Light gray */
    }

    .btn-purchase {
      display: block;
      width: 100%;
      padding: 1rem;
      font-size: 1.1rem;
      font-weight: 600;
      text-transform: uppercase;
      background: linear-gradient(145deg, #666666, #999999); /* Grayscale gradient */
      border: 2px solid #666666;
      border-radius: 2rem;
      color: #ffffff !important;
      text-align: center;
      transition: all 0.3s ease;
      opacity: 0.9;
    }

    .btn-purchase:hover {
      background: linear-gradient(145deg, #999999, #666666); /* Reverse grayscale gradient */
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.6);
      color: #cccccc !important;
      opacity: 1;
      text-decoration: none;
    }

    .guarantee-text {
      text-align: center;
      font-size: 0.9rem;
      color: #b0b0b0;
      margin-top: 1.5rem;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    .features-card {
      background: linear-gradient(145deg, #2a2a2a, #3a3a3a);
      border: 2px solid #666666;
      border-radius: 15px;
      padding: 25px;
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
    }

    .features-title {
      font-size: 1.5rem;
      font-weight: 600;
      color: #ffffff;
      margin-bottom: 1.5rem;
    }

    .feature-list .feature-item {
      font-size: 1rem;
      color: #b0b0b0;
      margin-bottom: 0.75rem;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .feature-item i {
      color: #cccccc;
    }

    .modern-modal {
      background: linear-gradient(145deg, #2a2a2a, #3a3a3a);
      border: 2px solid #666666;
      border-radius: 15px;
      color: #ffffff;
    }

    .modal-header {
      border-bottom: 1px solid #666666;
      padding: 20px;
    }

    .modal-title {
      font-size: 1.75rem;
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .modal-footer {
      border-top: 1px solid #666666;
      padding: 20px;
    }

    .modal-body {
      color: #b0b0b0;
      padding: 20px;
    }

    .course-summary h5 {
      font-size: 1.5rem;
      color: #ffffff;
      margin-bottom: 1rem;
    }

    .billing-form .form-group {
      margin-bottom: 1.5rem;
    }

    .billing-form label {
      font-size: 1rem;
      color: #b0b0b0;
      margin-bottom: 0.5rem;
    }

    .billing-form .form-control {
      background-color: #333333;
      border: 1px solid #666666;
      color: #ffffff;
      border-radius: 8px;
      padding: 10px;
    }

    .billing-form .form-control:focus {
      background-color: #333333;
      border-color: #999999; /* Light gray for focus */
      box-shadow: 0 0 5px rgba(153, 153, 153, 0.5);
      color: #ffffff;
    }

    .custom-checkbox label {
      font-size: 0.9rem;
      color: #b0b0b0;
    }

    .custom-checkbox a {
      color: #cccccc;
      text-decoration: underline;
    }

    .modal-footer .btn-secondary {
      background: #333333;
      border: 1px solid #666666;
      color: #ffffff;
      border-radius: 8px;
    }

    .modal-footer .btn-primary {
      background: linear-gradient(145deg, #666666, #999999);
      border: 1px solid #666666;
      color: #ffffff !important;
      border-radius: 8px;
    }

    .modal-footer .btn-primary:hover {
      background: linear-gradient(145deg, #999999, #666666);
      color: #cccccc !important;
    }

    /* Ensure proper z-index for modal and backdrop */
    .modal-backdrop {
      z-index: 1040 !important;
    }
    .modal {
      z-index: 1050 !important;
    }

    /* Animations */
    .fade-in {
      opacity: 0;
      transform: translateY(20px);
      animation: fadeIn 0.8s ease forwards;
    }

    @keyframes fadeIn {
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    /* Responsive Design */
    @media (max-width: 992px) {
      .product-title {
        font-size: 2.5rem;
      }
      .product-subtitle {
        font-size: 1.25rem;
      }
      .product-hero {
        padding: 30px;
      }
      .product-content-card {
        padding: 20px;
      }
      .section-title {
        font-size: 1.75rem;
      }
    }

    @media (max-width: 768px) {
      .product-title {
        font-size: 2rem;
      }
      .product-subtitle {
        font-size: 1rem;
      }
      .product-hero {
        padding: 20px;
      }
      .product-image-container {
        margin-top: 20px;
      }
      .product-meta {
        flex-direction: column;
        gap: 10px;
      }
      .product-content-card {
        padding: 15px;
      }
      .purchase-card, .features-card {
        padding: 20px;
      }
      .price-amount {
        font-size: 2rem;
      }
    }

    @media (max-width: 576px) {
      .product-title {
        font-size: 1.75rem;
      }
      .product-subtitle {
        font-size: 0.9rem;
      }
      .section-title {
        font-size: 1.5rem;
      }
      .product-hero {
        padding: 15px;
      }
      .product-image-container {
        margin-top: 15px;
      }
      .purchase-card, .features-card {
        padding: 15px;
      }
      .price-amount {
        font-size: 1.75rem;
      }
      .btn-purchase {
        font-size: 1rem;
        padding: 0.75rem;
      }
    }