:root {
            --primary-color: #1a365d;
            --secondary-color: #c53030;
            --accent-color: #ed8936;
            --light-color: #f7fafc;
            --dark-color: #2d3748;
            --gray-color: #a0aec0;
        }
        body {
            font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
            color: var(--dark-color);
            line-height: 1.7;
        }
        .navbar-brand {
            font-weight: 700;
            color: var(--primary-color);
        }
        .navbar-nav .nav-link {
            font-weight: 500;
            transition: color 0.3s;
        }
        .navbar-nav .nav-link:hover {
            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&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D&auto=format&fit=crop&w=2070&q=80') no-repeat center center;
            background-size: cover;
            color: white;
            padding: 120px 0 80px;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 40px;
            color: var(--primary-color);
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 70px;
            height: 4px;
            background-color: var(--secondary-color);
        }
        .section-title.center:after {
            left: 50%;
            transform: translateX(-50%);
        }
        .card-hover {
            transition: transform 0.3s, box-shadow 0.3s;
            height: 100%;
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
        }
        .product-card {
            border: 1px solid rgba(0, 0, 0, 0.1);
            border-radius: 8px;
            overflow: hidden;
            transition: all 0.3s;
        }
        .product-card:hover {
            border-color: var(--secondary-color);
        }
        .product-img {
            height: 220px;
            overflow: hidden;
        }
        .product-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s;
        }
        .product-card:hover .product-img img {
            transform: scale(1.05);
        }
        .icon-box {
            width: 70px;
            height: 70px;
            display: flex;
            align-items: center;
            justify-content: center;
            background-color: rgba(197, 48, 48, 0.1);
            color: var(--secondary-color);
            border-radius: 8px;
            margin-bottom: 20px;
            font-size: 32px;
        }
        .stats-box {
            background-color: var(--primary-color);
            color: white;
            padding: 30px 20px;
            border-radius: 8px;
            text-align: center;
        }
        .stats-number {
            font-size: 2.5rem;
            font-weight: 700;
            color: var(--accent-color);
        }
        .contact-info-box {
            padding: 25px;
            background-color: var(--light-color);
            border-radius: 8px;
            height: 100%;
            border-left: 4px solid var(--secondary-color);
        }
        .friendlink {
            display: inline-block;
            padding: 8px 16px;
            background-color: var(--light-color);
            border-radius: 4px;
            margin: 5px;
            color: var(--dark-color);
            text-decoration: none;
            transition: all 0.3s;
        }
        .friendlink:hover {
            background-color: var(--primary-color);
            color: white;
            transform: translateY(-3px);
        }
        .footer {
            background-color: var(--primary-color);
            color: white;
            padding-top: 60px;
        }
        .footer a {
            color: rgba(255, 255, 255, 0.8);
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer a:hover {
            color: var(--accent-color);
        }
        .footer-bottom {
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            padding: 20px 0;
            margin-top: 40px;
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--secondary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 20px;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s;
            z-index: 999;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 80px 0 40px;
            }
            .stats-number {
                font-size: 2rem;
            }
            .section-title {
                margin-bottom: 30px;
            }
        }