:root {
            --primary-color: #1a365d;
            --secondary-color: #2d7d9a;
            --accent-color: #e63946;
            --light-color: #f8f9fa;
            --dark-color: #212529;
            --gray-color: #6c757d;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
            color: var(--dark-color);
            line-height: 1.7;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5, h6 {
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 3rem;
            text-align: center;
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--secondary-color);
            border-radius: 2px;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
            color: var(--primary-color);
        }
        .navbar-brand span {
            color: var(--secondary-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=2070&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 180px 0 120px;
            margin-top: 76px;
        }
        .hero-section h1 {
            color: white;
            font-size: 3.5rem;
            margin-bottom: 1.5rem;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 12px 30px;
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        }
        .feature-card {
            background: white;
            border-radius: 10px;
            padding: 30px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            height: 100%;
            transition: var(--transition);
            border-top: 4px solid transparent;
        }
        .feature-card:hover {
            transform: translateY(-10px);
            border-top-color: var(--secondary-color);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .feature-icon {
            width: 70px;
            height: 70px;
            background: rgba(45, 125, 154, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
            color: var(--secondary-color);
            font-size: 1.8rem;
        }
        .product-card {
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
            transition: var(--transition);
            margin-bottom: 30px;
            background: white;
        }
        .product-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .product-img {
            height: 220px;
            overflow: hidden;
        }
        .product-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: var(--transition);
        }
        .product-card:hover .product-img img {
            transform: scale(1.05);
        }
        .product-info {
            padding: 25px;
        }
        .timeline {
            position: relative;
            max-width: 1200px;
            margin: 0 auto;
        }
        .timeline::after {
            content: '';
            position: absolute;
            width: 6px;
            background-color: var(--secondary-color);
            top: 0;
            bottom: 0;
            left: 50%;
            margin-left: -3px;
        }
        @media (max-width: 768px) {
            .timeline::after {
                left: 31px;
            }
        }
        .timeline-item {
            padding: 10px 40px;
            position: relative;
            width: 50%;
            box-sizing: border-box;
        }
        .timeline-item:nth-child(odd) {
            left: 0;
        }
        .timeline-item:nth-child(even) {
            left: 50%;
        }
        @media (max-width: 768px) {
            .timeline-item {
                width: 100%;
                padding-left: 70px;
                padding-right: 25px;
            }
            .timeline-item:nth-child(even) {
                left: 0;
            }
        }
        .timeline-content {
            padding: 20px;
            background-color: white;
            position: relative;
            border-radius: 6px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
        }
        .timeline-item:nth-child(odd) .timeline-content::after {
            content: '';
            position: absolute;
            width: 20px;
            height: 20px;
            right: -10px;
            background-color: white;
            top: 22px;
            border-radius: 50%;
            z-index: 1;
            transform: rotate(45deg);
            box-shadow: 3px -3px 5px rgba(0,0,0,0.05);
        }
        .timeline-item:nth-child(even) .timeline-content::after {
            content: '';
            position: absolute;
            width: 20px;
            height: 20px;
            left: -10px;
            background-color: white;
            top: 22px;
            border-radius: 50%;
            z-index: 1;
            transform: rotate(45deg);
            box-shadow: -3px 3px 5px rgba(0,0,0,0.05);
        }
        @media (max-width: 768px) {
            .timeline-content::after {
                left: 50px !important;
                right: auto !important;
            }
        }
        .contact-info-box {
            background: white;
            border-radius: 10px;
            padding: 30px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            text-align: center;
            transition: var(--transition);
            height: 100%;
        }
        .contact-info-box:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }
        .contact-icon {
            width: 70px;
            height: 70px;
            background: rgba(45, 125, 154, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
            color: var(--secondary-color);
            font-size: 1.8rem;
        }
        .friendlink {
            background-color: #f8f9fa;
            padding: 60px 0;
        }
        .flink {
            display: inline-block;
            background: white;
            padding: 12px 25px;
            margin: 8px;
            border-radius: 50px;
            color: var(--primary-color);
            text-decoration: none;
            font-weight: 500;
            transition: var(--transition);
            border: 1px solid #e9ecef;
            box-shadow: 0 3px 10px rgba(0,0,0,0.03);
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            border-color: var(--primary-color);
        }
        footer {
            background-color: var(--primary-color);
            color: rgba(255,255,255,0.8);
            padding: 60px 0 20px;
        }
        footer h5 {
            color: white;
            margin-bottom: 25px;
            position: relative;
            padding-bottom: 10px;
        }
        footer h5:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 40px;
            height: 3px;
            background: var(--secondary-color);
        }
        footer a {
            color: rgba(255,255,255,0.8);
            text-decoration: none;
            transition: var(--transition);
        }
        footer a:hover {
            color: white;
            padding-left: 5px;
        }
        .footer-bottom {
            border-top: 1px solid rgba(255,255,255,0.1);
            padding-top: 20px;
            margin-top: 40px;
            text-align: center;
            font-size: 0.9rem;
        }
        .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;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            z-index: 1000;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-5px);
        }