:root {
            --primary-color: #0056b3;
            --secondary-color: #ff6a00;
            --dark-color: #2c3e50;
            --light-color: #f8f9fa;
            --success-color: #28a745;
            --font-primary: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
        }
        body {
            font-family: var(--font-primary);
            color: #333;
            line-height: 1.8;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5, h6 {
            font-weight: 700;
            margin-bottom: 1rem;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 2px 15px rgba(0, 0, 0, 0.08);
            transition: all 0.3s ease;
            padding-top: 0.8rem;
            padding-bottom: 0.8rem;
        }
        .navbar.scrolled {
            padding-top: 0.5rem;
            padding-bottom: 0.5rem;
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .navbar-brand span {
            color: var(--secondary-color);
        }
        .nav-link {
            font-weight: 600;
            color: var(--dark-color) !important;
            margin: 0 0.5rem;
            position: relative;
        }
        .nav-link::after {
            content: '';
            position: absolute;
            width: 0;
            height: 3px;
            background: var(--secondary-color);
            left: 50%;
            bottom: -5px;
            transition: all 0.3s ease;
            transform: translateX(-50%);
        }
        .nav-link:hover::after,
        .nav-link.active::after {
            width: 80%;
        }
        .hero-section {
            background: linear-gradient(135deg, rgba(0, 86, 179, 0.85) 0%, rgba(44, 62, 80, 0.9) 100%), url('https://images.unsplash.com/photo-1581094794329-c8112a89af12?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') no-repeat center center;
            background-size: cover;
            color: white;
            padding: 10rem 0 8rem;
            position: relative;
        }
        .hero-title {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.3);
        }
        .hero-subtitle {
            font-size: 1.4rem;
            margin-bottom: 2rem;
            opacity: 0.9;
        }
        .section-title {
            position: relative;
            display: inline-block;
            margin-bottom: 3rem;
            color: var(--dark-color);
        }
        .section-title::after {
            content: '';
            position: absolute;
            width: 70%;
            height: 4px;
            background: var(--secondary-color);
            bottom: -10px;
            left: 15%;
        }
        .feature-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 1.5rem;
            transition: transform 0.3s ease;
        }
        .feature-card:hover .feature-icon {
            transform: translateY(-10px);
        }
        .product-card {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
            transition: all 0.4s ease;
            height: 100%;
        }
        .product-card:hover {
            transform: translateY(-15px);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
        }
        .product-img {
            height: 250px;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        .product-card:hover .product-img {
            transform: scale(1.05);
        }
        .timeline {
            position: relative;
            padding-left: 3rem;
            margin-top: 3rem;
        }
        .timeline::before {
            content: '';
            position: absolute;
            left: 7px;
            top: 0;
            bottom: 0;
            width: 3px;
            background: var(--primary-color);
        }
        .timeline-item {
            position: relative;
            margin-bottom: 2.5rem;
        }
        .timeline-item::before {
            content: '';
            position: absolute;
            left: -3.3rem;
            top: 5px;
            width: 15px;
            height: 15px;
            border-radius: 50%;
            background: var(--secondary-color);
            border: 3px solid white;
            box-shadow: 0 0 0 3px var(--primary-color);
        }
        .contact-info-box {
            background: var(--light-color);
            border-radius: 12px;
            padding: 2rem;
            height: 100%;
            transition: all 0.3s ease;
            border-left: 5px solid var(--primary-color);
        }
        .contact-info-box:hover {
            background: white;
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
        }
        .contact-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        footer {
            background-color: var(--dark-color);
            color: #ddd;
            padding-top: 3rem;
        }
        .footer-links h5 {
            color: white;
            margin-bottom: 1.5rem;
            position: relative;
            padding-bottom: 0.8rem;
        }
        .footer-links h5::after {
            content: '';
            position: absolute;
            left: 0;
            bottom: 0;
            width: 50px;
            height: 2px;
            background: var(--secondary-color);
        }
        .footer-links a {
            color: #bbb;
            text-decoration: none;
            display: block;
            margin-bottom: 0.8rem;
            transition: all 0.2s ease;
        }
        .footer-links a:hover {
            color: var(--secondary-color);
            padding-left: 8px;
        }
        .friendlink {
            background: rgba(255, 255, 255, 0.05);
            border-radius: 10px;
            padding: 2rem;
            margin-top: 2rem;
        }
        .flink {
            display: inline-block;
            background: rgba(255, 255, 255, 0.1);
            color: #ddd;
            padding: 0.5rem 1.2rem;
            margin: 0.5rem;
            border-radius: 50px;
            text-decoration: none;
            transition: all 0.3s ease;
            border: 1px solid transparent;
        }
        .flink:hover {
            background: transparent;
            color: var(--secondary-color);
            border-color: var(--secondary-color);
            transform: translateY(-3px);
        }
        .copyright {
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            padding: 1.5rem 0;
            margin-top: 3rem;
            font-size: 0.9rem;
            color: #aaa;
        }
        .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: 1.5rem;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: all 0.4s ease;
            z-index: 1000;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: var(--secondary-color);
            transform: translateY(-5px);
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.5rem;
            }
            .hero-subtitle {
                font-size: 1.2rem;
            }
            .navbar-nav {
                background: white;
                padding: 1rem;
                border-radius: 10px;
                box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
                margin-top: 1rem;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }