:root {
            --primary-color: #1a365d;
            --secondary-color: #0ea5e9;
            --accent-color: #10b981;
            --light-color: #f8fafc;
            --dark-color: #0f172a;
            --gray-color: #64748b;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: #333;
            line-height: 1.6;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            color: var(--primary-color);
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 2px 15px rgba(0, 0, 0, 0.08);
            padding: 1rem 0;
            transition: all 0.3s ease;
        }
        .navbar.scrolled {
            padding: 0.6rem 0;
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color);
        }
        .navbar-brand span {
            color: var(--secondary-color);
        }
        .nav-link {
            font-weight: 600;
            margin: 0 0.5rem;
            color: var(--dark-color);
            position: relative;
        }
        .nav-link:hover, .nav-link.active {
            color: var(--secondary-color);
        }
        .nav-link::after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            bottom: 0;
            left: 50%;
            background-color: var(--secondary-color);
            transition: all 0.3s ease;
        }
        .nav-link:hover::after, .nav-link.active::after {
            width: 80%;
            left: 10%;
        }
        .hero-section {
            background: linear-gradient(135deg, rgba(26, 54, 93, 0.9) 0%, rgba(14, 165, 233, 0.8) 100%), url('https://images.unsplash.com/photo-1581091226033-d5c48150dbaa?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80');
            background-size: cover;
            background-position: center;
            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 8px rgba(0, 0, 0, 0.3);
        }
        .hero-subtitle {
            font-size: 1.3rem;
            margin-bottom: 2.5rem;
            max-width: 700px;
        }
        .btn-primary {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            padding: 0.8rem 2.2rem;
            font-weight: 600;
            border-radius: 50px;
            transition: all 0.3s ease;
        }
        .btn-primary:hover {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
        }
        .section-title {
            font-size: 2.5rem;
            margin-bottom: 1rem;
            position: relative;
            padding-bottom: 1rem;
        }
        .section-title::after {
            content: '';
            position: absolute;
            width: 80px;
            height: 4px;
            background: var(--secondary-color);
            bottom: 0;
            left: 0;
        }
        .section-title.center::after {
            left: 50%;
            transform: translateX(-50%);
        }
        .feature-card {
            border: none;
            border-radius: 15px;
            overflow: hidden;
            transition: all 0.3s ease;
            height: 100%;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
        }
        .feature-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.12);
        }
        .feature-icon {
            width: 80px;
            height: 80px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--secondary-color), var(--accent-color));
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1.5rem;
        }
        .feature-icon i {
            font-size: 2rem;
            color: white;
        }
        .product-card {
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
            transition: all 0.3s ease;
            height: 100%;
        }
        .product-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 12px 25px rgba(0, 0, 0, 0.12);
        }
        .product-img {
            height: 220px;
            overflow: hidden;
        }
        .product-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        .product-card:hover .product-img img {
            transform: scale(1.05);
        }
        .timeline {
            position: relative;
            max-width: 1200px;
            margin: 0 auto;
        }
        .timeline::after {
            content: '';
            position: absolute;
            width: 4px;
            background-color: var(--secondary-color);
            top: 0;
            bottom: 0;
            left: 50%;
            margin-left: -2px;
        }
        .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;
            background-color: white;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
        }
        .timeline-item::after {
            content: '';
            position: absolute;
            width: 20px;
            height: 20px;
            background-color: white;
            border: 4px solid var(--secondary-color);
            border-radius: 50%;
            top: 15px;
            z-index: 1;
        }
        .timeline-item:nth-child(odd)::after {
            right: -10px;
        }
        .timeline-item:nth-child(even)::after {
            left: -10px;
        }
        .contact-info {
            background: linear-gradient(135deg, var(--primary-color), #2d4a80);
            color: white;
            border-radius: 15px;
            padding: 3rem;
        }
        .contact-icon {
            width: 60px;
            height: 60px;
            border-radius: 50%;
            background-color: rgba(255, 255, 255, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1rem;
        }
        .contact-icon i {
            font-size: 1.5rem;
            color: var(--secondary-color);
        }
        .friendlink {
            background-color: var(--light-color);
            padding: 4rem 0;
        }
        .flink {
            display: inline-block;
            padding: 0.8rem 1.8rem;
            margin: 0.5rem;
            background-color: white;
            border-radius: 50px;
            color: var(--dark-color);
            text-decoration: none;
            font-weight: 600;
            box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
            transition: all 0.3s ease;
            border: 1px solid #e2e8f0;
        }
        .flink:hover {
            background-color: var(--secondary-color);
            color: white;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(14, 165, 233, 0.2);
        }
        footer {
            background-color: var(--dark-color);
            color: #cbd5e1;
        }
        .footer-links a {
            color: #94a3b8;
            text-decoration: none;
            transition: color 0.3s ease;
        }
        .footer-links a:hover {
            color: var(--secondary-color);
        }
        .social-links a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background-color: #334155;
            color: white;
            margin-right: 0.8rem;
            transition: all 0.3s ease;
        }
        .social-links a:hover {
            background-color: var(--secondary-color);
            transform: translateY(-3px);
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.5rem;
            }
            .section-title {
                font-size: 2rem;
            }
            .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;
            }
            .contact-info {
                padding: 2rem;
            }
        }
        .animate-on-scroll {
            opacity: 0;
            transform: translateY(30px);
            transition: all 0.6s ease;
        }
        .animate-on-scroll.visible {
            opacity: 1;
            transform: translateY(0);
        }