:root {
            --primary-color: #0056b3;
            --secondary-color: #28a745;
            --accent-color: #ffc107;
            --dark-color: #343a40;
            --light-color: #f8f9fa;
            --transition-speed: 0.3s;
        }
        body {
            font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
            color: #333;
            overflow-x: hidden;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
            color: var(--primary-color);
        }
        .navbar-nav .nav-link {
            font-weight: 500;
            padding: 0.5rem 1rem;
            transition: color var(--transition-speed);
        }
        .navbar-nav .nav-link:hover {
            color: var(--secondary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(0, 86, 179, 0.85), rgba(40, 167, 69, 0.8)), url('https://images.unsplash.com/photo-1513475382585-d06e58bcb0e0?ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D&auto=format&fit=crop&w=2070&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 120px 0;
        }
        .section-title {
            position: relative;
            margin-bottom: 3rem;
            text-align: center;
            font-weight: 700;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--secondary-color);
        }
        .card-hover {
            transition: transform var(--transition-speed), box-shadow var(--transition-speed);
            border: none;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .service-icon {
            width: 80px;
            height: 80px;
            background: var(--primary-color);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            color: white;
            font-size: 2rem;
        }
        .product-img {
            height: 220px;
            object-fit: cover;
            width: 100%;
        }
        .contact-info-box {
            background-color: var(--light-color);
            border-left: 4px solid var(--primary-color);
            padding: 1.5rem;
            margin-bottom: 1.5rem;
            border-radius: 0 8px 8px 0;
        }
        .footer {
            background-color: var(--dark-color);
            color: white;
            padding-top: 3rem;
        }
        .flink {
            display: inline-block;
            padding: 0.5rem 1.2rem;
            margin: 0.3rem;
            background-color: rgba(255,255,255,0.1);
            border-radius: 4px;
            color: #ddd;
            text-decoration: none;
            transition: all var(--transition-speed);
        }
        .flink:hover {
            background-color: var(--secondary-color);
            color: white;
            transform: scale(1.05);
        }
        .back-to-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;
            font-size: 1.2rem;
            z-index: 1000;
            opacity: 0.8;
            transition: opacity var(--transition-speed);
        }
        .back-to-top:hover {
            opacity: 1;
        }
        .timeline-item {
            position: relative;
            padding-left: 30px;
            margin-bottom: 2rem;
        }
        .timeline-item::before {
            content: '';
            position: absolute;
            left: 0;
            top: 8px;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            background-color: var(--secondary-color);
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 80px 0;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }