:root {
            --primary-color: #0056b3;
            --secondary-color: #17a2b8;
            --accent-color: #28a745;
            --dark-color: #343a40;
            --light-color: #f8f9fa;
            --transition-speed: 0.3s;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            line-height: 1.6;
            color: #333;
            overflow-x: hidden;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
        }
        .navbar-nav .nav-link {
            font-weight: 500;
            padding: 0.5rem 1rem;
            transition: color var(--transition-speed);
        }
        .navbar-nav .nav-link:hover, .navbar-nav .nav-link.active {
            color: var(--primary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(0, 84, 179, 0.85), rgba(0, 84, 179, 0.9)), url('https://images.unsplash.com/photo-1558494949-ef010cbdcc31?ixlib=rb-4.0.3&auto=format&fit=crop&w=1350&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 120px 0;
            min-height: 80vh;
            display: flex;
            align-items: center;
        }
        .hero-title {
            font-size: 3rem;
            font-weight: 700;
            margin-bottom: 1.5rem;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.2rem;
            }
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 50px;
            font-weight: 700;
            color: var(--dark-color);
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 60px;
            height: 3px;
            background-color: var(--primary-color);
        }
        .text-center .section-title:after {
            left: 50%;
            transform: translateX(-50%);
        }
        .service-card {
            background: white;
            border-radius: 10px;
            padding: 30px;
            height: 100%;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: transform var(--transition-speed), box-shadow var(--transition-speed);
            border: 1px solid rgba(0,0,0,0.05);
        }
        .service-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .service-icon {
            width: 70px;
            height: 70px;
            background: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
            font-size: 1.8rem;
        }
        .project-card {
            position: relative;
            overflow: hidden;
            border-radius: 10px;
            margin-bottom: 30px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
        }
        .project-card img {
            transition: transform 0.5s;
            width: 100%;
            height: 250px;
            object-fit: cover;
        }
        .project-card:hover img {
            transform: scale(1.05);
        }
        .project-overlay {
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            background: rgba(0, 86, 179, 0.9);
            color: white;
            padding: 20px;
            transform: translateY(100%);
            transition: transform var(--transition-speed);
        }
        .project-card:hover .project-overlay {
            transform: translateY(0);
        }
        .contact-info-box {
            background: var(--light-color);
            padding: 30px;
            border-radius: 10px;
            height: 100%;
            border-left: 4px solid var(--primary-color);
        }
        .contact-icon {
            width: 50px;
            height: 50px;
            background: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
        }
        .friendlink {
            background: #f8f9fa;
            padding: 80px 0;
        }
        .flink {
            display: inline-block;
            padding: 10px 20px;
            margin: 5px 10px;
            background: white;
            border-radius: 5px;
            color: var(--dark-color);
            text-decoration: none;
            border: 1px solid #dee2e6;
            transition: all var(--transition-speed);
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
            transform: translateY(-3px);
        }
        footer {
            background: var(--dark-color);
            color: #adb5bd;
            padding-top: 60px;
        }
        footer a {
            color: #adb5bd;
            text-decoration: none;
            transition: color var(--transition-speed);
        }
        footer a:hover {
            color: white;
        }
        .footer-bottom {
            border-top: 1px solid #495057;
            padding: 20px 0;
            margin-top: 40px;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 10px 25px;
            border-radius: 5px;
            transition: all var(--transition-speed);
        }
        .btn-primary:hover {
            background-color: #004494;
            border-color: #004494;
            transform: translateY(-2px);
        }
        .timeline {
            position: relative;
            padding-left: 30px;
            margin-top: 30px;
        }
        .timeline:before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            bottom: 0;
            width: 3px;
            background: var(--primary-color);
        }
        .timeline-item {
            position: relative;
            margin-bottom: 40px;
            padding-left: 30px;
        }
        .timeline-item:before {
            content: '';
            position: absolute;
            left: -36px;
            top: 5px;
            width: 15px;
            height: 15px;
            border-radius: 50%;
            background: var(--primary-color);
            border: 3px solid white;
            box-shadow: 0 0 0 3px var(--primary-color);
        }
        .stats-box {
            text-align: center;
            padding: 30px;
            background: white;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            margin-bottom: 30px;
        }
        .stats-number {
            font-size: 3rem;
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 10px;
        }
        .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;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: all var(--transition-speed);
            z-index: 1000;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: #004494;
            color: white;
        }