:root {
            --primary: #111827;
            --secondary: #f97316;
            --danger: #dc2626;
            --success: #16a34a;
            --light-bg: #f8fafc;
            --border: #e5e7eb;
            --muted: #6b7280;
        }

        * {
            box-sizing: border-box;
        }

        body {
            font-family: Arial, Helvetica, sans-serif;
            color: #1f2937;
            background: #fff;
        }

        a {
            text-decoration: none;
        }

        /* =========================
           TOP BAR
        ========================= */

        .top-bar {
            background: var(--primary);
            color: #fff;
            font-size: 14px;
            padding: 8px 0;
        }

        /* =========================
           NAVBAR
        ========================= */

        .navbar {
            background: #fff;
            border-bottom: 1px solid var(--border);
            padding: 17px 0;
        }

        .navbar-brand {
            font-size: 28px;
            font-weight: 800;
            color: var(--primary);
        }

        .navbar-brand span {
            color: var(--secondary);
        }

        .nav-link {
            color: #374151 !important;
            font-weight: 500;
            margin: 0 8px;
        }

        .nav-link:hover,
        .nav-link.active {
            color: var(--secondary) !important;
        }

        .nav-icon {
            color: var(--primary);
            font-size: 21px;
            margin-left: 18px;
            position: relative;
        }

        .nav-icon:hover {
            color: var(--secondary);
        }

        .cart-count {
            position: absolute;
            top: -9px;
            right: -10px;
            width: 18px;
            height: 18px;
            background: var(--secondary);
            color: #fff;
            font-size: 10px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        /* =========================
           BREADCRUMB
        ========================= */

        .breadcrumb-section {
            background: var(--light-bg);
            padding: 18px 0;
        }

        .breadcrumb {
            margin: 0;
        }

        .breadcrumb-item a {
            color: var(--secondary);
        }

        /* =========================
           PRODUCT SECTION
        ========================= */

        .product-section {
            padding: 60px 0;
        }

        /* =========================
           PRODUCT GALLERY
        ========================= */

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

        .main-image {
            position: relative;
            background: #f3f4f6;
            border-radius: 12px;
            overflow: hidden;
            height: 560px;
        }

        .main-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .sale-badge {
            position: absolute;
            top: 18px;
            left: 18px;
            background: var(--danger);
            color: #fff;
            padding: 7px 12px;
            border-radius: 5px;
            font-size: 12px;
            font-weight: 800;
            z-index: 2;
        }

        .gallery-wishlist {
            position: absolute;
            top: 18px;
            right: 18px;
            width: 45px;
            height: 45px;
            background: #fff;
            border: none;
            border-radius: 50%;
            font-size: 20px;
            z-index: 2;
            transition: .3s;
        }

        .gallery-wishlist:hover {
            color: var(--secondary);
        }

        .thumbnail-container {
            display: flex;
            gap: 12px;
            margin-top: 15px;
            overflow-x: auto;
        }

        .thumbnail {
            flex: 0 0 85px;
            height: 85px;
            border: 2px solid transparent;
            border-radius: 8px;
            overflow: hidden;
            cursor: pointer;
            background: #f3f4f6;
        }

        .thumbnail.active {
            border-color: var(--secondary);
        }

        .thumbnail img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        /* =========================
           PRODUCT DETAILS
        ========================= */

        .product-details {
            padding-left: 25px;
        }

        .product-category {
            color: var(--secondary);
            text-transform: uppercase;
            letter-spacing: 1px;
            font-size: 13px;
            font-weight: 700;
            margin-bottom: 10px;
        }

        .product-title {
            font-size: 42px;
            line-height: 1.15;
            font-weight: 800;
            color: var(--primary);
            margin-bottom: 15px;
        }

        .product-rating {
            display: flex;
            align-items: center;
            gap: 10px;
            margin-bottom: 22px;
        }

        .stars {
            color: #f59e0b;
            letter-spacing: 2px;
        }

        .review-link {
            color: var(--muted);
            font-size: 14px;
        }

        .review-link:hover {
            color: var(--secondary);
        }

        .price-row {
            margin-bottom: 20px;
        }

        .current-price {
            font-size: 36px;
            font-weight: 800;
            color: var(--primary);
        }

        .old-price {
            font-size: 18px;
            color: #9ca3af;
            text-decoration: line-through;
            margin-left: 12px;
        }

        .discount {
            background: #dcfce7;
            color: var(--success);
            font-size: 13px;
            font-weight: 700;
            padding: 6px 9px;
            border-radius: 4px;
            margin-left: 10px;
        }

        .product-description {
            color: var(--muted);
            line-height: 1.8;
            border-bottom: 1px solid var(--border);
            padding-bottom: 25px;
        }

        /* =========================
           PRODUCT OPTIONS
        ========================= */

        .option-section {
            margin-top: 25px;
        }

        .option-label {
            font-weight: 700;
            margin-bottom: 12px;
        }

        .color-options {
            display: flex;
            gap: 10px;
        }

        .color-option {
            width: 38px;
            height: 38px;
            border-radius: 50%;
            border: 3px solid #fff;
            outline: 1px solid #d1d5db;
            cursor: pointer;
        }

        .color-option.active {
            outline: 2px solid var(--secondary);
        }

        .color-black {
            background: #111827;
        }

        .color-white {
            background: #fff;
        }

        .color-blue {
            background: #2563eb;
        }

        .color-red {
            background: #dc2626;
        }

        .size-options {
            display: flex;
            gap: 8px;
            flex-wrap: wrap;
        }

        .size-option {
            min-width: 55px;
            padding: 10px 15px;
            background: #fff;
            border: 1px solid #d1d5db;
            border-radius: 5px;
            cursor: pointer;
            text-align: center;
            font-weight: 600;
        }

        .size-option:hover,
        .size-option.active {
            border-color: var(--primary);
            background: var(--primary);
            color: #fff;
        }

        /* =========================
           QUANTITY
        ========================= */

        .purchase-row {
            display: flex;
            gap: 12px;
            align-items: center;
            margin-top: 30px;
        }

        .quantity {
            display: flex;
            height: 50px;
            border: 1px solid #d1d5db;
            border-radius: 6px;
            overflow: hidden;
        }

        .quantity button {
            width: 45px;
            border: none;
            background: #f9fafb;
            font-size: 18px;
        }

        .quantity input {
            width: 55px;
            border: none;
            text-align: center;
            font-weight: 700;
            outline: none;
        }

        .add-cart-btn {
            flex: 1;
            height: 50px;
            border: none;
            background: var(--primary);
            color: #fff;
            border-radius: 6px;
            font-weight: 700;
            font-size: 16px;
            transition: .3s;
        }

        .add-cart-btn:hover {
            background: var(--secondary);
        }

        .buy-now-btn {
            width: 100%;
            height: 50px;
            border: 1px solid var(--primary);
            background: #fff;
            color: var(--primary);
            border-radius: 6px;
            margin-top: 12px;
            font-weight: 700;
            transition: .3s;
        }

        .buy-now-btn:hover {
            background: var(--primary);
            color: #fff;
        }

        /* =========================
           PRODUCT BENEFITS
        ========================= */

        .product-benefits {
            margin-top: 30px;
            border-top: 1px solid var(--border);
        }

        .benefit {
            display: flex;
            align-items: center;
            gap: 15px;
            padding: 15px 0;
            border-bottom: 1px solid var(--border);
        }

        .benefit i {
            color: var(--secondary);
            font-size: 23px;
        }

        .benefit strong {
            display: block;
            font-size: 14px;
        }

        .benefit span {
            display: block;
            color: var(--muted);
            font-size: 13px;
            margin-top: 2px;
        }

        /* =========================
           PRODUCT INFO TABS
        ========================= */

        .product-tabs-section {
            padding: 20px 0 80px;
        }

        .product-tabs {
            border-bottom: 1px solid var(--border);
        }

        .product-tabs .nav-link {
            border: none;
            border-radius: 0;
            padding: 17px 25px;
            color: var(--muted) !important;
            margin: 0;
            font-weight: 700;
        }

        .product-tabs .nav-link.active {
            color: var(--primary) !important;
            border-bottom: 3px solid var(--secondary);
            background: transparent;
        }

        .tab-content {
            padding: 35px 0;
        }

        .tab-content p {
            color: var(--muted);
            line-height: 1.8;
        }

        .spec-table {
            width: 100%;
        }

        .spec-table tr {
            border-bottom: 1px solid var(--border);
        }

        .spec-table td {
            padding: 13px 10px;
        }

        .spec-table td:first-child {
            font-weight: 700;
            width: 30%;
        }

        /* =========================
           REVIEWS
        ========================= */

        .review-summary {
            background: var(--light-bg);
            border-radius: 10px;
            padding: 30px;
            text-align: center;
        }

        .rating-number {
            font-size: 55px;
            font-weight: 800;
        }

        .rating-stars {
            color: #f59e0b;
            font-size: 20px;
        }

        .rating-bars {
            padding: 10px 20px;
        }

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

        .rating-row span {
            font-size: 13px;
        }

        .progress {
            height: 7px;
            flex: 1;
        }

        .customer-review {
            padding: 25px 0;
            border-bottom: 1px solid var(--border);
        }

        .review-avatar {
            width: 45px;
            height: 45px;
            background: var(--primary);
            color: #fff;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
        }

        /* =========================
           RELATED PRODUCTS
        ========================= */

        .related-section {
            background: var(--light-bg);
            padding: 80px 0;
        }

        .section-title {
            font-size: 35px;
            font-weight: 800;
        }

        .section-subtitle {
            color: var(--muted);
        }

        .product-card {
            background: #fff;
            border: 1px solid var(--border);
            border-radius: 10px;
            overflow: hidden;
            height: 100%;
            transition: .3s;
        }

        .product-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 30px rgba(0,0,0,.08);
        }

        .card-image {
            height: 250px;
            position: relative;
            background: #f3f4f6;
            overflow: hidden;
        }

        .card-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: .4s;
        }

        .product-card:hover .card-image img {
            transform: scale(1.06);
        }

        .card-wishlist {
            position: absolute;
            right: 15px;
            top: 15px;
            width: 38px;
            height: 38px;
            border: none;
            background: #fff;
            border-radius: 50%;
        }

        .card-info {
            padding: 18px;
        }

        .card-category {
            font-size: 12px;
            color: var(--muted);
            text-transform: uppercase;
        }

        .card-title {
            font-weight: 700;
            color: var(--primary);
            margin: 7px 0;
        }

        .card-price {
            font-size: 19px;
            font-weight: 800;
        }

        .card-old-price {
            color: #9ca3af;
            text-decoration: line-through;
            font-size: 13px;
            margin-left: 5px;
        }

        /* =========================
           FOOTER
        ========================= */

        footer {
            background: var(--primary);
            color: #d1d5db;
            padding: 65px 0 20px;
        }

        footer h5 {
            color: #fff;
            font-weight: 700;
            margin-bottom: 20px;
        }

        footer a {
            color: #9ca3af;
            display: block;
            margin-bottom: 10px;
        }

        footer a:hover {
            color: #fff;
        }

        .social-icons a {
            display: inline-flex;
            width: 38px;
            height: 38px;
            border: 1px solid #374151;
            border-radius: 50%;
            align-items: center;
            justify-content: center;
            margin-right: 5px;
        }

        .copyright {
            border-top: 1px solid #374151;
            margin-top: 40px;
            padding-top: 20px;
            text-align: center;
            color: #9ca3af;
            font-size: 14px;
        }

        /* =========================
           RESPONSIVE
        ========================= */

        @media (max-width: 991px) {

            .product-gallery {
                position: static;
            }

            .product-details {
                padding-left: 0;
                margin-top: 40px;
            }

        }

        @media (max-width: 768px) {

            .product-section {
                padding: 35px 0;
            }

            .main-image {
                height: 420px;
            }

            .product-title {
                font-size: 32px;
            }

            .current-price {
                font-size: 30px;
            }

            .purchase-row {
                flex-wrap: wrap;
            }

            .quantity {
                width: 100%;
            }

            .quantity button {
                flex: 1;
            }

            .quantity input {
                flex: 2;
            }

            .add-cart-btn {
                flex-basis: 100%;
            }

            .product-tabs .nav-link {
                padding: 13px 10px;
                font-size: 14px;
            }

        }