:root {
            --primary-color: #0066cc;
            --secondary-color: #004d99;
            --accent-color: #00a8e8;
            --light-color: #f8f9fa;
            --dark-color: #343a40;
            --success-color: #28a745;
        }
        body {
            font-family: "Microsoft YaHei", "Segoe UI", sans-serif;
            line-height: 1.8;
            color: #333;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
            padding: 1rem 0;
            transition: all 0.3s ease;
        }
        .navbar-brand {
            font-weight: 700;
            color: var(--primary-color);
            font-size: 1.5rem;
        }
        .navbar-brand span {
            color: var(--secondary-color);
        }
        .nav-link {
            font-weight: 500;
            margin: 0 0.5rem;
            color: var(--dark-color);
            transition: color 0.3s;
        }
        .nav-link:hover, .nav-link.active {
            color: var(--primary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(0, 51, 102, 0.85), rgba(0, 77, 153, 0.8)), url('https://images.unsplash.com/photo-1581094794329-c8112a89af12?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 10rem 0 8rem;
            position: relative;
        }
        .hero-title {
            font-size: 3.5rem;
            font-weight: 700;
            margin-bottom: 1.5rem;
            text-shadow: 2px 2px 5px rgba(0, 0, 0, 0.3);
        }
        .hero-subtitle {
            font-size: 1.5rem;
            margin-bottom: 2rem;
            opacity: 0.9;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            border-radius: 50px;
            transition: all 0.3s;
        }
        .btn-primary:hover {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
        }
        .service-card {
            border-radius: 10px;
            overflow: hidden;
            border: none;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
            transition: transform 0.3s, box-shadow 0.3s;
            height: 100%;
        }
        .service-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }
        .service-icon {
            width: 80px;
            height: 80px;
            background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            color: white;
            font-size: 2rem;
        }
        .product-card {
            border: 1px solid #eee;
            border-radius: 10px;
            overflow: hidden;
            transition: all 0.3s;
            height: 100%;
        }
        .product-card:hover {
            border-color: var(--primary-color);
            box-shadow: 0 10px 25px rgba(0, 102, 204, 0.1);
        }
        .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);
        }
        .about-section {
            background-color: #f9f9f9;
            padding: 6rem 0;
        }
        .section-title {
            position: relative;
            margin-bottom: 3rem;
            font-weight: 700;
            color: var(--dark-color);
        }
        .section-title:after {
            content: '';
            position: absolute;
            left: 0;
            bottom: -10px;
            width: 60px;
            height: 4px;
            background: var(--primary-color);
        }
        .section-title.text-center:after {
            left: 50%;
            transform: translateX(-50%);
        }
        .feature-box {
            padding: 2rem;
            background: white;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            height: 100%;
            transition: all 0.3s;
        }
        .feature-box:hover {
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
        }
        .feature-icon {
            color: var(--primary-color);
            font-size: 2.5rem;
            margin-bottom: 1.5rem;
        }
        .case-study {
            position: relative;
            overflow: hidden;
            border-radius: 10px;
            margin-bottom: 2rem;
        }
        .case-img {
            height: 300px;
            overflow: hidden;
        }
        .case-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s;
        }
        .case-overlay {
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            background: linear-gradient(transparent, rgba(0, 0, 0, 0.8));
            color: white;
            padding: 2rem;
            transform: translateY(20px);
            opacity: 0;
            transition: all 0.3s;
        }
        .case-study:hover .case-overlay {
            transform: translateY(0);
            opacity: 1;
        }
        .case-study:hover .case-img img {
            transform: scale(1.05);
        }
        .news-card {
            border: none;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            height: 100%;
            transition: all 0.3s;
        }
        .news-card:hover {
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
        }
        .news-date {
            background: var(--primary-color);
            color: white;
            padding: 0.5rem 1rem;
            display: inline-block;
            border-radius: 5px;
            font-weight: 600;
            margin-bottom: 1rem;
        }
        .contact-info {
            padding: 2rem;
            background: white;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            height: 100%;
        }
        .contact-icon {
            width: 60px;
            height: 60px;
            background: #f0f7ff;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--primary-color);
            font-size: 1.5rem;
            margin-bottom: 1rem;
        }
        .friendlink {
            background-color: #f5f7fa;
            padding: 4rem 0;
        }
        .flink {
            display: inline-block;
            background: white;
            padding: 0.8rem 1.5rem;
            margin: 0.5rem;
            border-radius: 50px;
            color: var(--dark-color);
            text-decoration: none;
            font-weight: 500;
            box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
            transition: all 0.3s;
            border: 1px solid #eee;
        }
        .flink:hover {
            color: var(--primary-color);
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
            border-color: var(--primary-color);
        }
        footer {
            background-color: var(--dark-color);
            color: #aaa;
            padding-top: 4rem;
        }
        .footer-title {
            color: white;
            font-size: 1.2rem;
            font-weight: 600;
            margin-bottom: 1.5rem;
            position: relative;
            padding-bottom: 0.8rem;
        }
        .footer-title:after {
            content: '';
            position: absolute;
            left: 0;
            bottom: 0;
            width: 40px;
            height: 3px;
            background: var(--primary-color);
        }
        .footer-links li {
            margin-bottom: 0.8rem;
        }
        .footer-links a {
            color: #aaa;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer-links a:hover {
            color: white;
            padding-left: 5px;
        }
        .copyright {
            background-color: rgba(0, 0, 0, 0.2);
            padding: 1.5rem 0;
            margin-top: 3rem;
            border-top: 1px solid rgba(255, 255, 255, 0.05);
        }
        @media (max-width: 992px) {
            .hero-title {
                font-size: 2.8rem;
            }
            .hero-subtitle {
                font-size: 1.3rem;
            }
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 7rem 0 5rem;
            }
            .hero-title {
                font-size: 2.2rem;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }
        @media (max-width: 576px) {
            .hero-title {
                font-size: 1.8rem;
            }
            .hero-subtitle {
                font-size: 1.1rem;
            }
            .section-title {
                font-size: 1.6rem;
            }
        }
        .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;
            text-decoration: none;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s;
            box-shadow: 0 3px 10px rgba(0, 0, 0, 0.2);
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: var(--secondary-color);
            color: white;
            transform: translateY(-5px);
        }
        .fade-in {
            opacity: 0;
            transform: translateY(20px);
            transition: opacity 0.6s, transform 0.6s;
        }
        .fade-in.visible {
            opacity: 1;
            transform: translateY(0);
        }
        .form-control {
            padding: 0.75rem 1rem;
            border-radius: 5px;
            border: 1px solid #ddd;
            transition: all 0.3s;
        }
        .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 0.25rem rgba(0, 102, 204, 0.25);
        }