:root {
            --primary-color: #0a4a7a;
            --secondary-color: #f8b417;
            --accent-color: #2ecc71;
            --dark-color: #1a252f;
            --light-color: #f8f9fa;
        }
        body {
            font-family: 'Microsoft YaHei', 'Segoe UI', sans-serif;
            color: #333;
            line-height: 1.6;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .nav-link {
            font-weight: 500;
            transition: color 0.3s;
        }
        .nav-link:hover {
            color: var(--secondary-color) !important;
        }
        .hero-section {
            background: linear-gradient(rgba(10, 74, 122, 0.85), rgba(10, 74, 122, 0.9)), url('https://images.unsplash.com/photo-1541888946425-d81bb19240f5?ixlib=rb-4.0.3&auto=format&fit=crop&w=1770&q=80') center/cover no-repeat;
            color: white;
            padding: 8rem 0;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 3rem;
            font-weight: 700;
            color: var(--primary-color);
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 60px;
            height: 4px;
            background-color: var(--secondary-color);
        }
        .service-card {
            border: none;
            border-radius: 10px;
            overflow: hidden;
            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, 0.1);
        }
        .service-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 1.5rem;
        }
        .project-img {
            height: 250px;
            object-fit: cover;
            transition: transform 0.5s;
        }
        .project-card:hover .project-img {
            transform: scale(1.05);
        }
        .news-card {
            border-left: 4px solid var(--primary-color);
            transition: background-color 0.3s;
        }
        .news-card:hover {
            background-color: rgba(10, 74, 122, 0.05);
        }
        .contact-info-box {
            background-color: var(--light-color);
            border-radius: 10px;
            padding: 2rem;
            height: 100%;
            border-top: 4px solid var(--secondary-color);
        }
        .contact-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .flink {
            display: inline-block;
            padding: 8px 20px;
            margin: 5px;
            background-color: #f1f5f9;
            border-radius: 5px;
            color: var(--dark-color);
            text-decoration: none;
            transition: all 0.3s;
            border: 1px solid #ddd;
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            transform: translateY(-3px);
        }
        footer {
            background-color: var(--dark-color);
            color: #ccc;
        }
        footer a {
            color: #ccc;
            text-decoration: none;
            transition: color 0.3s;
        }
        footer a:hover {
            color: var(--secondary-color);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            text-decoration: none;
            opacity: 0;
            transition: opacity 0.3s, background-color 0.3s;
            z-index: 1000;
        }
        .back-to-top.show {
            opacity: 1;
        }
        .back-to-top:hover {
            background-color: var(--secondary-color);
            color: var(--dark-color);
        }
        .btn-custom {
            background-color: var(--primary-color);
            color: white;
            padding: 10px 30px;
            border-radius: 5px;
            border: none;
            transition: background-color 0.3s;
        }
        .btn-custom:hover {
            background-color: var(--secondary-color);
            color: var(--dark-color);
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 5rem 0;
            }
            .display-4 {
                font-size: 2.2rem;
            }
        }