:root {
            --primary-color: #0056b3;
            --secondary-color: #28a745;
            --accent-color: #ffc107;
            --light-color: #f8f9fa;
            --dark-color: #343a40;
        }
        body {
            font-family: 'Microsoft YaHei', sans-serif;
            color: #333;
            line-height: 1.6;
        }
        .navbar-brand {
            font-weight: bold;
            font-size: 1.5rem;
        }
        .hero-section {
            background: linear-gradient(rgba(0, 84, 179, 0.8), rgba(0, 84, 179, 0.9)), url('https://images.unsplash.com/photo-1545324418-cc1a3fa10c00?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80') center/cover no-repeat;
            color: white;
            padding: 120px 0;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 40px;
            text-align: center;
            font-weight: bold;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--primary-color);
        }
        .card {
            border: none;
            border-radius: 10px;
            overflow: hidden;
            transition: transform 0.3s, box-shadow 0.3s;
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .card-img-top {
            height: 220px;
            object-fit: cover;
        }
        .service-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 20px;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border: none;
            padding: 12px 30px;
            border-radius: 30px;
            transition: background 0.3s;
        }
        .btn-primary:hover {
            background-color: #004494;
        }
        .contact-info i {
            color: var(--primary-color);
            margin-right: 10px;
        }
        .friendlink a.flink {
            display: inline-block;
            margin: 5px 15px;
            padding: 8px 20px;
            background: var(--light-color);
            border-radius: 20px;
            color: var(--dark-color);
            text-decoration: none;
            transition: all 0.3s;
        }
        .friendlink a.flink:hover {
            background: var(--primary-color);
            color: white;
            transform: scale(1.05);
        }
        footer {
            background: var(--dark-color);
            color: white;
        }
        .social-icons a {
            color: white;
            margin: 0 10px;
            font-size: 1.5rem;
            transition: color 0.3s;
        }
        .social-icons a:hover {
            color: var(--accent-color);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            background: var(--primary-color);
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            opacity: 0.8;
            transition: opacity 0.3s;
            z-index: 1000;
        }
        .back-to-top:hover {
            opacity: 1;
        }
        .project-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 20px;
        }
        .news-item {
            border-left: 4px solid var(--primary-color);
            padding-left: 15px;
            margin-bottom: 20px;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2rem;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }