:root {
            --primary-color: #1a5f7a;
            --secondary-color: #57cc99;
            --accent-color: #ff9a3c;
            --dark-color: #2d4059;
            --light-color: #f8f9fa;
            --text-dark: #333333;
            --text-light: #666666;
            --shadow: 0 5px 15px rgba(0,0,0,0.08);
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Microsoft YaHei', 'Segoe UI', sans-serif;
            color: var(--text-dark);
            line-height: 1.7;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5, h6 {
            font-weight: 700;
            color: var(--dark-color);
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.98);
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            padding: 15px 0;
            transition: var(--transition);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color);
        }
        .navbar-brand span {
            color: var(--accent-color);
        }
        .nav-link {
            font-weight: 600;
            margin: 0 8px;
            color: var(--dark-color);
            position: relative;
        }
        .nav-link:hover, .nav-link.active {
            color: var(--primary-color);
        }
        .nav-link:after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            background: var(--primary-color);
            left: 0;
            bottom: 0;
            transition: var(--transition);
        }
        .nav-link:hover:after, .nav-link.active:after {
            width: 100%;
        }
        .hero-section {
            background: linear-gradient(rgba(26, 95, 122, 0.85), rgba(45, 64, 89, 0.9)), url('https://images.unsplash.com/photo-1504307651254-35680f356dfd?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 180px 0 120px;
            position: relative;
        }
        .hero-title {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 25px;
            text-shadow: 2px 2px 8px rgba(0,0,0,0.3);
        }
        .hero-subtitle {
            font-size: 1.3rem;
            margin-bottom: 40px;
            max-width: 700px;
            opacity: 0.9;
        }
        .section-title {
            position: relative;
            margin-bottom: 60px;
            text-align: center;
        }
        .section-title:after {
            content: '';
            position: absolute;
            width: 80px;
            height: 4px;
            background: var(--secondary-color);
            bottom: -15px;
            left: 50%;
            transform: translateX(-50%);
            border-radius: 2px;
        }
        .section-padding {
            padding: 100px 0;
        }
        .card {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: var(--transition);
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .card-icon {
            width: 70px;
            height: 70px;
            background: var(--primary-color);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 25px;
            color: white;
            font-size: 1.8rem;
        }
        .service-card {
            border-top: 5px solid var(--primary-color);
        }
        .service-card:hover {
            border-top-color: var(--secondary-color);
        }
        .project-card {
            position: relative;
            overflow: hidden;
        }
        .project-overlay {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(26, 95, 122, 0.9);
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            opacity: 0;
            transition: var(--transition);
            padding: 20px;
            color: white;
            text-align: center;
        }
        .project-card:hover .project-overlay {
            opacity: 1;
        }
        .stats-section {
            background: linear-gradient(rgba(26, 95, 122, 0.9), rgba(45, 64, 89, 0.9)), url('https://images.unsplash.com/photo-1503387769-00b1123e8e6b?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80');
            background-size: cover;
            background-position: center;
            background-attachment: fixed;
            color: white;
            padding: 100px 0;
        }
        .stat-item {
            text-align: center;
        }
        .stat-number {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 10px;
            color: var(--secondary-color);
        }
        .stat-text {
            font-size: 1.2rem;
            font-weight: 600;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 12px 30px;
            font-weight: 600;
            border-radius: 30px;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        }
        .btn-secondary {
            background-color: transparent;
            border: 2px solid white;
            color: white;
            padding: 12px 30px;
            font-weight: 600;
            border-radius: 30px;
            transition: var(--transition);
        }
        .btn-secondary:hover {
            background-color: white;
            color: var(--primary-color);
            transform: translateY(-3px);
        }
        .contact-info {
            background-color: var(--light-color);
            padding: 40px 30px;
            border-radius: 12px;
            box-shadow: var(--shadow);
            height: 100%;
        }
        .contact-item {
            display: flex;
            align-items: flex-start;
            margin-bottom: 30px;
        }
        .contact-icon {
            width: 50px;
            height: 50px;
            background: var(--primary-color);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 1.3rem;
            margin-right: 20px;
            flex-shrink: 0;
        }
        .friendlink {
            background-color: #f5f7fa;
            padding: 80px 0;
        }
        .flink {
            display: inline-block;
            background-color: white;
            padding: 15px 25px;
            margin: 10px;
            border-radius: 8px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            color: var(--text-dark);
            font-weight: 600;
            transition: var(--transition);
            text-decoration: none;
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            transform: translateY(-5px);
        }
        footer {
            background-color: var(--dark-color);
            color: white;
            padding: 80px 0 30px;
        }
        .footer-links h5 {
            color: white;
            margin-bottom: 25px;
            position: relative;
            padding-bottom: 10px;
        }
        .footer-links h5:after {
            content: '';
            position: absolute;
            width: 40px;
            height: 3px;
            background: var(--secondary-color);
            bottom: 0;
            left: 0;
        }
        .footer-links ul {
            list-style: none;
            padding-left: 0;
        }
        .footer-links li {
            margin-bottom: 12px;
        }
        .footer-links a {
            color: #ccc;
            text-decoration: none;
            transition: var(--transition);
        }
        .footer-links a:hover {
            color: var(--secondary-color);
            padding-left: 5px;
        }
        .copyright {
            border-top: 1px solid rgba(255,255,255,0.1);
            padding-top: 30px;
            margin-top: 50px;
            text-align: center;
            color: #aaa;
            font-size: 0.9rem;
        }
        .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: 1.3rem;
            z-index: 999;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            text-decoration: none;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--secondary-color);
            color: white;
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.5rem;
            }
            .section-padding {
                padding: 60px 0;
            }
            .hero-section {
                padding: 140px 0 80px;
            }
            .stat-number {
                font-size: 2.5rem;
            }
            .navbar-nav {
                text-align: center;
                padding-top: 20px;
            }
        }
        .timeline {
            position: relative;
            max-width: 1200px;
            margin: 0 auto;
        }
        .timeline:after {
            content: '';
            position: absolute;
            width: 6px;
            background-color: var(--primary-color);
            top: 0;
            bottom: 0;
            left: 50%;
            margin-left: -3px;
        }
        .timeline-item {
            padding: 10px 40px;
            position: relative;
            width: 50%;
            box-sizing: border-box;
        }
        .timeline-item:nth-child(odd) {
            left: 0;
        }
        .timeline-item:nth-child(even) {
            left: 50%;
        }
        .timeline-content {
            padding: 20px 30px;
            background-color: white;
            position: relative;
            border-radius: 12px;
            box-shadow: var(--shadow);
        }
        .timeline-item:after {
            content: '';
            position: absolute;
            width: 25px;
            height: 25px;
            right: -13px;
            background-color: white;
            border: 4px solid var(--primary-color);
            top: 15px;
            border-radius: 50%;
            z-index: 1;
        }
        .timeline-item:nth-child(even):after {
            left: -12px;
        }
        @media screen and (max-width: 768px) {
            .timeline:after {
                left: 31px;
            }
            .timeline-item {
                width: 100%;
                padding-left: 70px;
                padding-right: 25px;
            }
            .timeline-item:nth-child(even) {
                left: 0;
            }
            .timeline-item:after {
                left: 18px;
            }
            .timeline-item:nth-child(even):after {
                left: 18px;
            }
        }
        .form-control {
            padding: 15px;
            border-radius: 8px;
            border: 1px solid #ddd;
            margin-bottom: 20px;
            transition: var(--transition);
        }
        .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 0.25rem rgba(26, 95, 122, 0.25);
        }
        textarea.form-control {
            min-height: 150px;
            resize: vertical;
        }