:root {
            --primary-color: #0056b3;
            --secondary-color: #28a745;
            --accent-color: #ff6b35;
            --light-color: #f8f9fa;
            --dark-color: #343a40;
            --gray-color: #6c757d;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: 'Microsoft YaHei', 'Segoe UI', Arial, sans-serif;
            line-height: 1.8;
            color: #333;
            overflow-x: hidden;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .navbar-brand span {
            color: var(--accent-color);
        }
        .nav-link {
            font-weight: 500;
            margin: 0 8px;
            transition: all 0.3s;
            position: relative;
        }
        .nav-link:hover, .nav-link.active {
            color: var(--primary-color) !important;
        }
        .nav-link::after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            background: var(--primary-color);
            left: 50%;
            bottom: 0;
            transition: all 0.3s;
            transform: translateX(-50%);
        }
        .nav-link:hover::after, .nav-link.active::after {
            width: 80%;
        }
        .hero-section {
            background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('https://images.unsplash.com/photo-1581094794329-c8112a89af12?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 150px 0;
            position: relative;
        }
        .hero-section h1 {
            font-size: 3.5rem;
            font-weight: 700;
            margin-bottom: 25px;
            text-shadow: 2px 2px 5px rgba(0,0,0,0.5);
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
            .hero-section {
                padding: 100px 0;
            }
        }
        .section-title {
            position: relative;
            margin-bottom: 50px;
            text-align: center;
        }
        .section-title h2 {
            font-size: 2.5rem;
            font-weight: 700;
            color: var(--dark-color);
            display: inline-block;
            padding-bottom: 15px;
        }
        .section-title h2::after {
            content: '';
            position: absolute;
            width: 80px;
            height: 4px;
            background: var(--primary-color);
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            border-radius: 2px;
        }
        .card-hover {
            transition: transform 0.3s, box-shadow 0.3s;
            border: none;
            border-radius: 10px;
            overflow: hidden;
            height: 100%;
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .icon-box {
            width: 80px;
            height: 80px;
            border-radius: 50%;
            background: var(--light-color);
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
            color: var(--primary-color);
            font-size: 2rem;
        }
        .btn-primary-custom {
            background: var(--primary-color);
            border: none;
            padding: 12px 30px;
            border-radius: 30px;
            font-weight: 600;
            transition: all 0.3s;
        }
        .btn-primary-custom:hover {
            background: #004494;
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(0,86,179,0.2);
        }
        .process-step {
            position: relative;
            padding: 20px;
            text-align: center;
        }
        .process-step .step-number {
            width: 50px;
            height: 50px;
            background: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            font-size: 1.5rem;
            margin: 0 auto 20px;
            z-index: 2;
            position: relative;
        }
        .process-line {
            position: absolute;
            top: 25px;
            left: 50%;
            width: 100%;
            height: 3px;
            background: #e9ecef;
            z-index: 1;
        }
        @media (max-width: 768px) {
            .process-line {
                display: none;
            }
        }
        .product-card {
            border-radius: 10px;
            overflow: hidden;
            margin-bottom: 30px;
            transition: all 0.3s;
            border: 1px solid #eee;
        }
        .product-card img {
            height: 250px;
            object-fit: cover;
            width: 100%;
            transition: transform 0.5s;
        }
        .product-card:hover img {
            transform: scale(1.05);
        }
        .product-card .product-info {
            padding: 20px;
        }
        .footer {
            background: var(--dark-color);
            color: white;
            padding: 60px 0 20px;
        }
        .footer a {
            color: #ddd;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer a:hover {
            color: white;
            text-decoration: underline;
        }
        .footer h5 {
            color: white;
            margin-bottom: 25px;
            font-weight: 600;
            position: relative;
            padding-bottom: 10px;
        }
        .footer h5::after {
            content: '';
            position: absolute;
            width: 50px;
            height: 2px;
            background: var(--primary-color);
            bottom: 0;
            left: 0;
        }
        .copyright {
            border-top: 1px solid #444;
            padding-top: 20px;
            margin-top: 40px;
            text-align: center;
            color: #aaa;
            font-size: 0.9rem;
        }
        .friendlink-section {
            background: #f8f9fa;
            padding: 50px 0;
        }
        .flink {
            display: inline-block;
            padding: 8px 20px;
            margin: 5px 10px;
            background: white;
            border-radius: 30px;
            border: 1px solid #ddd;
            color: var(--dark-color);
            text-decoration: none;
            transition: all 0.3s;
            font-weight: 500;
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
            transform: translateY(-3px);
        }
        .contact-info i {
            width: 40px;
            height: 40px;
            background: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            margin-right: 15px;
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s;
            z-index: 1000;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: #004494;
            color: white;
        }
        .timeline {
            position: relative;
            max-width: 1200px;
            margin: 0 auto;
        }
        .timeline::after {
            content: '';
            position: absolute;
            width: 6px;
            background-color: var(--primary-color);
            top: 0;
            bottom: 0;
            left: 50%;
            margin-left: -3px;
        }
        .timeline-item {
            padding: 10px 40px;
            position: relative;
            width: 50%;
            box-sizing: border-box;
        }
        .timeline-item:nth-child(odd) {
            left: 0;
        }
        .timeline-item:nth-child(even) {
            left: 50%;
        }
        .timeline-content {
            padding: 20px 30px;
            background-color: white;
            position: relative;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        .timeline-item::after {
            content: '';
            position: absolute;
            width: 20px;
            height: 20px;
            background-color: white;
            border: 4px solid var(--primary-color);
            border-radius: 50%;
            top: 20px;
            z-index: 1;
        }
        .timeline-item:nth-child(odd)::after {
            right: -10px;
        }
        .timeline-item:nth-child(even)::after {
            left: -10px;
        }
        @media (max-width: 768px) {
            .timeline::after {
                left: 31px;
            }
            .timeline-item {
                width: 100%;
                padding-left: 70px;
                padding-right: 25px;
            }
            .timeline-item:nth-child(even) {
                left: 0;
            }
            .timeline-item::after {
                left: 21px;
            }
            .timeline-item:nth-child(odd)::after,
            .timeline-item:nth-child(even)::after {
                left: 21px;
            }
        }
        .cert-badge {
            display: inline-block;
            padding: 5px 15px;
            background: #e9f7ef;
            color: var(--secondary-color);
            border-radius: 20px;
            font-size: 0.9rem;
            margin: 5px;
            border: 1px solid #c3e6cb;
        }