:root {
            --primary-color: #1a5f7a;
            --secondary-color: #2d8c9f;
            --accent-color: #e67e22;
            --light-color: #f8f9fa;
            --dark-color: #343a40;
            --text-color: #333;
            --border-radius: 8px;
            --box-shadow: 0 5px 15px rgba(0,0,0,0.08);
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: var(--text-color);
            line-height: 1.6;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 40px;
            text-align: center;
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--accent-color);
            border-radius: 2px;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 2px 10px rgba(0,0,0,0.08);
            padding: 15px 0;
            transition: var(--transition);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color);
        }
        .navbar-nav .nav-link {
            font-weight: 600;
            color: var(--dark-color);
            margin: 0 10px;
            transition: var(--transition);
        }
        .navbar-nav .nav-link:hover {
            color: var(--accent-color);
        }
        .hero-section {
            background: linear-gradient(rgba(0,0,0,0.7), rgba(0,0,0,0.7)), url('https://images.unsplash.com/photo-1541888946425-d81bb19240f5?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 150px 0 100px;
            text-align: center;
        }
        .hero-section h1 {
            color: white;
            font-size: 3.5rem;
            margin-bottom: 20px;
            text-shadow: 2px 2px 8px rgba(0,0,0,0.5);
        }
        .hero-section p {
            font-size: 1.3rem;
            max-width: 800px;
            margin: 0 auto 30px;
            opacity: 0.9;
        }
        .btn-primary {
            background-color: var(--accent-color);
            border-color: var(--accent-color);
            padding: 12px 30px;
            border-radius: var(--border-radius);
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: #d35400;
            border-color: #d35400;
            transform: translateY(-3px);
            box-shadow: var(--box-shadow);
        }
        .feature-card {
            background: white;
            border-radius: var(--border-radius);
            padding: 30px;
            height: 100%;
            box-shadow: var(--box-shadow);
            transition: var(--transition);
            border: 1px solid rgba(0,0,0,0.05);
        }
        .feature-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .feature-icon {
            width: 70px;
            height: 70px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
            color: white;
            font-size: 1.8rem;
        }
        .about-section {
            padding: 100px 0;
            background-color: #f9f9f9;
        }
        .product-card {
            border-radius: var(--border-radius);
            overflow: hidden;
            box-shadow: var(--box-shadow);
            transition: var(--transition);
            background: white;
            height: 100%;
        }
        .product-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.12);
        }
        .product-img {
            height: 220px;
            width: 100%;
            object-fit: cover;
        }
        .product-body {
            padding: 25px;
        }
        .news-section {
            background-color: #f1f8ff;
            padding: 100px 0;
        }
        .news-card {
            border-radius: var(--border-radius);
            overflow: hidden;
            background: white;
            box-shadow: var(--box-shadow);
            transition: var(--transition);
            height: 100%;
        }
        .news-card:hover {
            transform: translateY(-5px);
        }
        .news-date {
            background-color: var(--primary-color);
            color: white;
            padding: 10px 15px;
            display: inline-block;
            border-radius: 4px;
            font-weight: 600;
            margin-bottom: 15px;
        }
        .contact-section {
            padding: 100px 0;
            background: linear-gradient(rgba(26, 95, 122, 0.9), rgba(26, 95, 122, 0.9)), url('https://images.unsplash.com/photo-1558618666-fcd25c85cd64?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80');
            background-size: cover;
            background-position: center;
            color: white;
        }
        .contact-info {
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: var(--border-radius);
            padding: 30px;
            margin-bottom: 30px;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }
        .contact-icon {
            width: 60px;
            height: 60px;
            background: rgba(255, 255, 255, 0.2);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
            font-size: 1.5rem;
        }
        footer {
            background-color: var(--dark-color);
            color: rgba(255, 255, 255, 0.8);
            padding: 70px 0 20px;
        }
        .footer-links h5 {
            color: white;
            margin-bottom: 20px;
            font-size: 1.2rem;
        }
        .footer-links ul {
            list-style: none;
            padding-left: 0;
        }
        .footer-links li {
            margin-bottom: 10px;
        }
        .footer-links a {
            color: rgba(255, 255, 255, 0.7);
            text-decoration: none;
            transition: var(--transition);
        }
        .footer-links a:hover {
            color: var(--accent-color);
            padding-left: 5px;
        }
        .copyright {
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            padding-top: 20px;
            margin-top: 50px;
            text-align: center;
            font-size: 0.9rem;
        }
        .friendlink {
            padding: 60px 0;
            background-color: #f8f9fa;
        }
        .flink {
            display: inline-block;
            background: white;
            padding: 12px 25px;
            margin: 8px;
            border-radius: 50px;
            text-decoration: none;
            color: var(--primary-color);
            font-weight: 600;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            transition: var(--transition);
            border: 1px solid #eee;
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            transform: translateY(-3px);
        }
        .stat-number {
            font-size: 3rem;
            font-weight: 800;
            color: var(--accent-color);
            margin-bottom: 5px;
        }
        .stat-label {
            font-size: 1.1rem;
            color: var(--dark-color);
            font-weight: 600;
        }
        .timeline {
            position: relative;
            max-width: 800px;
            margin: 0 auto;
        }
        .timeline:before {
            content: '';
            position: absolute;
            left: 50%;
            top: 0;
            bottom: 0;
            width: 2px;
            background-color: var(--primary-color);
            transform: translateX(-50%);
        }
        .timeline-item {
            margin-bottom: 50px;
            position: relative;
            width: 45%;
        }
        .timeline-item:nth-child(odd) {
            margin-left: 55%;
        }
        .timeline-item:nth-child(even) {
            margin-right: 55%;
        }
        .timeline-content {
            background: white;
            padding: 25px;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            position: relative;
        }
        .timeline-content:before {
            content: '';
            position: absolute;
            top: 20px;
            width: 20px;
            height: 20px;
            background-color: white;
            transform: rotate(45deg);
        }
        .timeline-item:nth-child(odd) .timeline-content:before {
            left: -10px;
        }
        .timeline-item:nth-child(even) .timeline-content:before {
            right: -10px;
        }
        .timeline-year {
            position: absolute;
            top: 15px;
            background-color: var(--primary-color);
            color: white;
            padding: 8px 15px;
            border-radius: 30px;
            font-weight: 700;
            z-index: 1;
        }
        .timeline-item:nth-child(odd) .timeline-year {
            left: -75px;
        }
        .timeline-item:nth-child(even) .timeline-year {
            right: -75px;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
            .timeline:before {
                left: 30px;
            }
            .timeline-item {
                width: 100%;
                margin-left: 60px !important;
                margin-right: 0 !important;
            }
            .timeline-item:nth-child(odd) .timeline-year,
            .timeline-item:nth-child(even) .timeline-year {
                left: -70px;
                right: auto;
            }
            .timeline-item:nth-child(odd) .timeline-content:before,
            .timeline-item:nth-child(even) .timeline-content:before {
                left: -10px;
                right: auto;
            }
        }
        .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: 1.2rem;
            cursor: pointer;
            z-index: 999;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            box-shadow: 0 3px 10px rgba(0,0,0,0.2);
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: #d35400;
            transform: translateY(-3px);
        }