:root {
            --primary-color: #0056a6;
            --secondary-color: #2d862d;
            --accent-color: #e67e22;
            --light-color: #f8f9fa;
            --dark-color: #343a40;
            --gray-color: #6c757d;
        }
        body {
            font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
            line-height: 1.7;
            color: var(--dark-color);
            overflow-x: hidden;
        }
        .hero-section {
            background: linear-gradient(rgba(0, 84, 166, 0.85), rgba(0, 84, 166, 0.9)), url('https://images.unsplash.com/photo-1532094349884-543bc11b234d?ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D&auto=format&fit=crop&w=1920&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 8rem 0;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 40px;
            text-align: center;
            color: var(--primary-color);
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 3px;
            background-color: var(--accent-color);
        }
        .card-hover {
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border: none;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .btn-primary-custom {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 10px 30px;
            font-weight: 600;
            transition: all 0.3s;
        }
        .btn-primary-custom:hover {
            background-color: #004085;
            border-color: #004085;
            transform: scale(1.05);
        }
        .product-card {
            height: 100%;
            border-radius: 10px;
            overflow: hidden;
        }
        .flink {
            display: inline-block;
            padding: 8px 20px;
            margin: 5px;
            background-color: #f1f8ff;
            border: 1px solid #d1e7ff;
            border-radius: 5px;
            color: var(--primary-color);
            text-decoration: none;
            transition: all 0.3s;
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            transform: translateY(-3px);
        }
        .footer {
            background-color: #2c3e50;
            color: #ecf0f1;
        }
        .footer a {
            color: #bdc3c7;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer a:hover {
            color: white;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
        }
        .icon-feature {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 15px;
        }
        .contact-info i {
            width: 40px;
            color: var(--primary-color);
        }
        .sticky-nav {
            position: sticky;
            top: 0;
            z-index: 1020;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
        .scroll-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            opacity: 0;
            transition: opacity 0.3s, transform 0.3s;
            z-index: 1000;
        }
        .scroll-top.show {
            opacity: 1;
        }
        .scroll-top:hover {
            transform: translateY(-5px);
        }
        .timeline {
            position: relative;
            padding-left: 30px;
        }
        .timeline:before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            bottom: 0;
            width: 3px;
            background-color: var(--primary-color);
        }
        .timeline-item {
            position: relative;
            margin-bottom: 30px;
        }
        .timeline-item:before {
            content: '';
            position: absolute;
            left: -36px;
            top: 5px;
            width: 15px;
            height: 15px;
            border-radius: 50%;
            background-color: var(--accent-color);
            border: 3px solid white;
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 5rem 0;
            }
            .display-4 {
                font-size: 2.2rem;
            }
            .section-title {
                margin-bottom: 30px;
            }
        }