:root {
            --primary-color: #1a365d;
            --secondary-color: #2d3748;
            --accent-color: #2b6cb0;
            --light-color: #f7fafc;
            --dark-color: #2d3748;
            --success-color: #38a169;
            --warning-color: #d69e2e;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            line-height: 1.6;
            color: #333;
            background-color: #fff;
        }
        h1, h2, h3, h4 {
            color: var(--primary-color);
            font-weight: 600;
        }
        .hero-section {
            background: linear-gradient(135deg, rgba(26, 54, 93, 0.9) 0%, rgba(43, 108, 176, 0.85) 100%), url('https://images.unsplash.com/photo-1497366754035-f200968a6e72?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') no-repeat center center;
            background-size: cover;
            color: white;
            padding: 120px 0;
        }
        .hero-section h1 {
            color: white;
            text-shadow: 1px 1px 3px rgba(0,0,0,0.3);
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 40px;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 60px;
            height: 3px;
            background-color: var(--accent-color);
        }
        .card-hover {
            transition: all 0.3s ease;
            border: 1px solid #e2e8f0;
        }
        .card-hover:hover {
            transform: translateY(-8px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
            border-color: var(--accent-color);
        }
        .service-icon {
            width: 70px;
            height: 70px;
            background-color: rgba(43, 108, 176, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
            color: var(--accent-color);
            font-size: 28px;
        }
        .navbar {
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            background-color: rgba(255, 255, 255, 0.98);
        }
        .navbar-brand {
            font-weight: 700;
            color: var(--primary-color);
            font-size: 1.5rem;
        }
        .nav-link {
            color: var(--secondary-color);
            font-weight: 500;
            margin: 0 5px;
            transition: color 0.3s;
        }
        .nav-link:hover {
            color: var(--accent-color);
        }
        .btn-primary {
            background-color: var(--accent-color);
            border-color: var(--accent-color);
            padding: 10px 25px;
            font-weight: 500;
            transition: all 0.3s;
        }
        .btn-primary:hover {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            transform: translateY(-2px);
        }
        .footer {
            background-color: var(--primary-color);
            color: white;
            padding: 60px 0 20px;
        }
        .footer a {
            color: #cbd5e0;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer a:hover {
            color: white;
        }
        .contact-info i {
            width: 20px;
            margin-right: 10px;
            color: var(--accent-color);
        }
        .flink {
            display: inline-block;
            padding: 8px 15px;
            margin: 5px;
            background-color: rgba(255,255,255,0.1);
            border-radius: 4px;
            transition: all 0.3s;
            color: #cbd5e0;
            text-decoration: none;
        }
        .flink:hover {
            background-color: var(--accent-color);
            color: white;
            transform: translateY(-3px);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--accent-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 20px;
            text-decoration: none;
            opacity: 0;
            transition: all 0.3s;
            z-index: 1000;
        }
        .back-to-top.show {
            opacity: 1;
        }
        .product-img {
            height: 200px;
            object-fit: cover;
            transition: transform 0.5s;
        }
        .product-card:hover .product-img {
            transform: scale(1.05);
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 80px 0;
            }
            .hero-section h1 {
                font-size: 2rem;
            }
            .section-title {
                font-size: 1.5rem;
            }
        }
        .certificate-badge {
            background-color: var(--success-color);
            color: white;
            padding: 5px 15px;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 500;
            display: inline-block;
            margin-bottom: 15px;
        }
        .timeline {
            position: relative;
            padding-left: 30px;
        }
        .timeline::before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            bottom: 0;
            width: 2px;
            background-color: var(--accent-color);
        }
        .timeline-item {
            position: relative;
            margin-bottom: 30px;
        }
        .timeline-item::before {
            content: '';
            position: absolute;
            left: -35px;
            top: 5px;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            background-color: var(--accent-color);
            border: 2px solid white;
            box-shadow: 0 0 0 3px var(--accent-color);
        }
        .stats-number {
            font-size: 2.5rem;
            font-weight: 700;
            color: var(--accent-color);
            margin-bottom: 5px;
        }
        .stats-label {
            font-size: 1rem;
            color: var(--secondary-color);
        }