:root {
            --primary-color: #0056b3;
            --secondary-color: #28a745;
            --dark-color: #343a40;
            --light-color: #f8f9fa;
            --accent-color: #ffc107;
            --transition: all 0.3s ease;
        }
        body {
            font-family: "Microsoft YaHei", "Segoe UI", sans-serif;
            line-height: 1.8;
            color: #333;
            overflow-x: hidden;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
        }
        .navbar-brand span {
            color: var(--primary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('https://images.unsplash.com/photo-1581094794329-c8112a89af12?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80') no-repeat center center/cover;
            color: white;
            padding: 150px 0;
            position: relative;
        }
        .section-title {
            position: relative;
            margin-bottom: 3rem;
            text-align: center;
            font-weight: 700;
            color: var(--dark-color);
        }
        .section-title:after {
            content: '';
            position: absolute;
            width: 80px;
            height: 4px;
            background: var(--primary-color);
            bottom: -15px;
            left: 50%;
            transform: translateX(-50%);
            border-radius: 2px;
        }
        .card-hover {
            transition: var(--transition);
            border: none;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            height: 100%;
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .product-img {
            height: 220px;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        .card-hover:hover .product-img {
            transform: scale(1.05);
        }
        .icon-box {
            width: 70px;
            height: 70px;
            background: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            font-size: 1.8rem;
            transition: var(--transition);
        }
        .feature-item:hover .icon-box {
            background: var(--secondary-color);
            transform: rotateY(180deg);
        }
        .bg-light-gradient {
            background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 10px 30px;
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: #004494;
            border-color: #004494;
            transform: translateY(-2px);
        }
        .contact-info li {
            margin-bottom: 1rem;
            display: flex;
            align-items: center;
        }
        .contact-info i {
            width: 40px;
            color: var(--primary-color);
            font-size: 1.2rem;
        }
        .footer {
            background-color: var(--dark-color);
            color: #ccc;
            padding-top: 3rem;
        }
        .footer a {
            color: #ccc;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer a:hover {
            color: white;
        }
        .friendlink {
            background-color: #2c3136;
            padding: 1.5rem;
            border-radius: 8px;
        }
        .flink {
            display: inline-block;
            margin: 5px 10px;
            padding: 8px 15px;
            background: rgba(255,255,255,0.1);
            border-radius: 4px;
            transition: var(--transition);
        }
        .flink:hover {
            background: rgba(255,255,255,0.2);
            transform: translateY(-3px);
        }
        .news-card {
            border-left: 4px solid var(--primary-color);
        }
        .timeline {
            position: relative;
            padding-left: 30px;
        }
        .timeline:before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            bottom: 0;
            width: 3px;
            background: var(--primary-color);
        }
        .timeline-item {
            position: relative;
            margin-bottom: 2rem;
        }
        .timeline-item:before {
            content: '';
            position: absolute;
            left: -36px;
            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);
        }
        .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: 1.2rem;
            opacity: 0;
            visibility: hidden;
            transition: all 0.4s ease;
            z-index: 1000;
            text-decoration: none;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: var(--secondary-color);
            color: white;
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 100px 0;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }