:root {
            --primary-color: #0056b3;
            --secondary-color: #28a745;
            --accent-color: #ffc107;
            --light-bg: #f8f9fa;
            --dark-text: #343a40;
        }
        body {
            font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
            color: var(--dark-text);
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            margin-bottom: 1rem;
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .nav-link {
            font-weight: 600;
            margin: 0 0.5rem;
            transition: color 0.3s;
        }
        .nav-link:hover {
            color: var(--secondary-color) !important;
        }
        .hero-section {
            background: linear-gradient(rgba(0, 84, 179, 0.9), rgba(40, 167, 69, 0.8)), url('https://images.unsplash.com/photo-1516321318423-f06f85e504b3?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80') no-repeat center center/cover;
            color: white;
            padding: 8rem 0;
            margin-top: 76px;
        }
        .hero-title {
            font-size: 3.5rem;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.5rem;
            }
        }
        .section-title {
            position: relative;
            padding-bottom: 1rem;
            margin-bottom: 3rem;
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--secondary-color);
        }
        .card {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            transition: transform 0.3s, box-shadow 0.3s;
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1) !important;
        }
        .service-icon, .feature-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 1.5rem;
        }
        .bg-light-custom {
            background-color: var(--light-bg);
        }
        .product-img {
            height: 220px;
            object-fit: cover;
            transition: transform 0.5s;
        }
        .product-card:hover .product-img {
            transform: scale(1.05);
        }
        .btn-primary-custom {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            border-radius: 30px;
        }
        .btn-primary-custom:hover {
            background-color: #004494;
            border-color: #004494;
            transform: scale(1.05);
        }
        .footer {
            background-color: #2c3e50;
            color: #ecf0f1;
            padding-top: 3rem;
        }
        .footer a {
            color: #bdc3c7;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer a:hover {
            color: white;
            text-decoration: underline;
        }
        .flink {
            display: inline-block;
            background: rgba(255,255,255,0.1);
            color: #bdc3c7;
            padding: 8px 20px;
            margin: 5px;
            border-radius: 30px;
            transition: all 0.3s;
            text-decoration: none !important;
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-3px);
        }
        .contact-info li {
            margin-bottom: 1rem;
            font-size: 1.1rem;
        }
        .contact-info i {
            color: var(--secondary-color);
            width: 30px;
        }
        .timeline {
            position: relative;
            padding-left: 2rem;
        }
        .timeline:before {
            content: '';
            position: absolute;
            left: 7px;
            top: 0;
            bottom: 0;
            width: 3px;
            background: var(--primary-color);
        }
        .timeline-item {
            position: relative;
            margin-bottom: 2rem;
        }
        .timeline-item:before {
            content: '';
            position: absolute;
            left: -2.3rem;
            top: 5px;
            width: 15px;
            height: 15px;
            border-radius: 50%;
            background: var(--secondary-color);
            border: 3px solid white;
            box-shadow: 0 0 0 3px var(--secondary-color);
        }
        .certificate-logo {
            max-height: 80px;
            filter: grayscale(30%);
            transition: filter 0.3s;
        }
        .certificate-logo:hover {
            filter: grayscale(0);
        }
        .news-card {
            border-left: 4px solid transparent;
            transition: border-color 0.3s;
        }
        .news-card:hover {
            border-left-color: var(--secondary-color);
        }
        .stats-number {
            font-size: 3rem;
            font-weight: 800;
            color: var(--primary-color);
            line-height: 1;
        }
        .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: 1.5rem;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--secondary-color);
            transform: scale(1.1);
        }