:root {
            --primary-color: #1a365d;
            --secondary-color: #c53030;
            --accent-color: #ed8936;
            --light-color: #f7fafc;
            --dark-color: #2d3748;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
            color: #333;
            line-height: 1.7;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            color: var(--primary-color);
        }
        .section-title {
            position: relative;
            margin-bottom: 3rem;
            padding-bottom: 1rem;
            text-align: center;
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--secondary-color);
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
            padding: 1rem 0;
            transition: var(--transition);
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
            color: var(--primary-color);
        }
        .navbar-nav .nav-link {
            font-weight: 500;
            padding: 0.5rem 1.2rem;
            color: var(--dark-color);
            transition: var(--transition);
        }
        .navbar-nav .nav-link:hover, .navbar-nav .nav-link.active {
            color: var(--secondary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(26, 54, 93, 0.85), rgba(26, 54, 93, 0.9)), url('https://images.unsplash.com/photo-1581094794329-c8112a89af12?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') center/cover no-repeat;
            color: white;
            padding: 8rem 0;
            position: relative;
        }
        .hero-title {
            font-size: 3.2rem;
            margin-bottom: 1.5rem;
            text-shadow: 1px 1px 3px rgba(0,0,0,0.3);
        }
        .hero-subtitle {
            font-size: 1.3rem;
            margin-bottom: 2rem;
            opacity: 0.9;
        }
        .btn-primary-custom {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            color: white;
            padding: 0.75rem 2rem;
            border-radius: 4px;
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary-custom:hover {
            background-color: #9b2c2c;
            border-color: #9b2c2c;
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        }
        .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);
        }
        .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-card:hover .icon-box {
            background: var(--secondary-color);
            transform: scale(1.1);
        }
        .product-img {
            height: 220px;
            object-fit: cover;
            transition: var(--transition);
        }
        .product-card:hover .product-img {
            transform: scale(1.05);
        }
        .contact-info-box {
            background: var(--light-color);
            border-left: 4px solid var(--secondary-color);
            padding: 1.5rem;
            margin-bottom: 1.5rem;
            transition: var(--transition);
        }
        .contact-info-box:hover {
            background: white;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
        }
        .footer {
            background-color: var(--primary-color);
            color: rgba(255,255,255,0.8);
            padding-top: 3rem;
        }
        .footer a {
            color: rgba(255,255,255,0.8);
            text-decoration: none;
            transition: var(--transition);
        }
        .footer a:hover {
            color: white;
            text-decoration: underline;
        }
        .friendlink {
            background-color: #f8f9fa;
            padding: 3rem 0;
        }
        .flink {
            display: inline-block;
            background: white;
            padding: 0.5rem 1.5rem;
            margin: 0.5rem;
            border-radius: 4px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.05);
            color: var(--dark-color);
            transition: var(--transition);
            font-weight: 500;
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-3px);
            text-decoration: none;
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background: var(--secondary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: var(--primary-color);
            color: white;
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.3rem;
            }
            .hero-subtitle {
                font-size: 1.1rem;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }