:root {
            --primary-color: #0056b3;
            --secondary-color: #ff6b35;
            --dark-color: #333;
            --light-color: #f8f9fa;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Microsoft YaHei', 'Segoe UI', sans-serif;
            color: var(--dark-color);
            line-height: 1.6;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            padding: 1rem 0;
            transition: var(--transition);
        }
        .navbar-brand {
            font-weight: bold;
            font-size: 1.8rem;
            color: var(--primary-color);
        }
        .navbar-nav .nav-link {
            color: var(--dark-color);
            font-weight: 500;
            margin: 0 0.5rem;
            transition: var(--transition);
        }
        .navbar-nav .nav-link:hover,
        .navbar-nav .nav-link.active {
            color: var(--primary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(0, 86, 179, 0.8), rgba(0, 86, 179, 0.9)), url('https://images.unsplash.com/photo-1450101499163-c8848c66ca85?ixlib=rb-4.0.3&auto=format&fit=crop&w=1600&q=80') no-repeat center center/cover;
            color: white;
            padding: 8rem 0;
            text-align: center;
        }
        .hero-section h1 {
            font-size: 3.5rem;
            font-weight: bold;
            margin-bottom: 1.5rem;
        }
        .hero-section p {
            font-size: 1.2rem;
            max-width: 800px;
            margin: 0 auto 2rem;
        }
        .btn-primary-custom {
            background-color: var(--secondary-color);
            border: none;
            padding: 0.8rem 2rem;
            font-weight: bold;
            border-radius: 50px;
            transition: var(--transition);
        }
        .btn-primary-custom:hover {
            background-color: #e05a2b;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.2);
        }
        .section-title {
            text-align: center;
            margin-bottom: 3rem;
            color: var(--primary-color);
            font-weight: bold;
            position: relative;
            padding-bottom: 1rem;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--secondary-color);
        }
        .service-card, .product-card, .case-card, .team-card, .news-card {
            border: none;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: var(--transition);
            height: 100%;
            background: white;
        }
        .service-card:hover, .product-card:hover, .case-card:hover, .team-card:hover, .news-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .service-icon, .product-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 1.5rem;
        }
        .img-fluid {
            border-radius: 10px 10px 0 0;
        }
        .card-body {
            padding: 2rem;
        }
        .contact-info i {
            color: var(--primary-color);
            margin-right: 1rem;
            font-size: 1.5rem;
        }
        .contact-form .form-control {
            border-radius: 10px;
            padding: 0.8rem;
            border: 1px solid #ddd;
            transition: var(--transition);
        }
        .contact-form .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 0.2rem rgba(0, 86, 179, 0.25);
        }
        footer {
            background-color: var(--dark-color);
            color: white;
            padding: 3rem 0 1.5rem;
        }
        footer a {
            color: #ccc;
            text-decoration: none;
            transition: var(--transition);
        }
        footer a:hover {
            color: white;
        }
        .friendlink {
            background-color: var(--light-color);
            padding: 3rem 0;
        }
        .flink {
            display: inline-block;
            margin: 0.5rem 1rem;
            padding: 0.5rem 1.5rem;
            background-color: white;
            border-radius: 50px;
            color: var(--dark-color);
            text-decoration: none;
            box-shadow: 0 3px 10px rgba(0,0,0,0.05);
            transition: var(--transition);
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            transform: translateY(-3px);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            background-color: var(--primary-color);
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            font-size: 1.5rem;
            z-index: 1000;
            opacity: 0;
            transition: var(--transition);
        }
        .back-to-top.active {
            opacity: 1;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
            .hero-section p {
                font-size: 1rem;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }