:root {
            --primary-color: #2563eb;
            --secondary-color: #1e40af;
            --accent-color: #3b82f6;
            --light-color: #f8fafc;
            --dark-color: #1e293b;
            --text-color: #334155;
            --border-radius: 8px;
            --box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            --transition: all 0.3s ease;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: 'Helvetica Neue', Arial, 'PingFang SC', 'Microsoft YaHei', sans-serif;
            line-height: 1.6;
            color: var(--text-color);
            background-color: #ffffff;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            color: var(--dark-color);
            margin-bottom: 1rem;
        }
        a {
            text-decoration: none;
            color: var(--primary-color);
            transition: var(--transition);
        }
        a:hover {
            color: var(--secondary-color);
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 0.75rem 2rem;
            border-radius: var(--border-radius);
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            transform: translateY(-2px);
            box-shadow: var(--box-shadow);
        }
        .section-padding {
            padding: 5rem 0;
        }
        .section-title {
            position: relative;
            margin-bottom: 3rem;
            text-align: center;
        }
        .section-title:after {
            content: '';
            position: absolute;
            width: 80px;
            height: 4px;
            background: var(--primary-color);
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            border-radius: 2px;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            padding: 1rem 0;
            position: fixed;
            top: 0;
            width: 100%;
            z-index: 1030;
            transition: var(--transition);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color);
            display: flex;
            align-items: center;
        }
        .navbar-brand i {
            margin-right: 0.5rem;
            font-size: 2rem;
        }
        .nav-link {
            font-weight: 600;
            margin: 0 0.5rem;
            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: 3px;
            background: var(--primary-color);
            bottom: 0;
            left: 0;
            transition: width 0.3s ease;
            border-radius: 2px;
        }
        .nav-link:hover:after, .nav-link.active:after {
            width: 100%;
        }
        .hero-section {
            background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
            color: white;
            padding: 10rem 0 5rem;
            margin-top: 76px;
            position: relative;
            overflow: hidden;
        }
        .hero-section h1 {
            color: white;
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
        }
        .hero-section p {
            font-size: 1.25rem;
            opacity: 0.9;
            margin-bottom: 2rem;
        }
        .hero-section .btn-primary {
            background-color: white;
            color: var(--primary-color);
            border: none;
        }
        .hero-section .btn-primary:hover {
            background-color: var(--light-color);
            color: var(--secondary-color);
        }
        .hero-image {
            position: relative;
            border-radius: var(--border-radius);
            overflow: hidden;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
            transform: perspective(1000px) rotateY(-10deg);
            transition: var(--transition);
        }
        .hero-image:hover {
            transform: perspective(1000px) rotateY(0deg);
        }
        .service-card {
            background: white;
            border-radius: var(--border-radius);
            padding: 2rem;
            height: 100%;
            box-shadow: var(--box-shadow);
            transition: var(--transition);
            border: 1px solid #e2e8f0;
            text-align: center;
        }
        .service-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
            border-color: var(--accent-color);
        }
        .service-icon {
            width: 80px;
            height: 80px;
            background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            color: white;
            font-size: 2rem;
        }
        .portfolio-item {
            position: relative;
            border-radius: var(--border-radius);
            overflow: hidden;
            margin-bottom: 1.5rem;
            box-shadow: var(--box-shadow);
            height: 300px;
        }
        .portfolio-img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: var(--transition);
        }
        .portfolio-overlay {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(30, 64, 175, 0.85);
            color: white;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            padding: 2rem;
            opacity: 0;
            transition: var(--transition);
        }
        .portfolio-item:hover .portfolio-overlay {
            opacity: 1;
        }
        .portfolio-item:hover .portfolio-img {
            transform: scale(1.05);
        }
        .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;
            border-radius: 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;
            background-color: white;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            position: relative;
        }
        .timeline-item:nth-child(odd) .timeline-content::after {
            content: '';
            position: absolute;
            width: 20px;
            height: 20px;
            right: -10px;
            background-color: white;
            top: 15px;
            border-radius: 50%;
            z-index: 1;
        }
        .timeline-item:nth-child(even) .timeline-content::after {
            content: '';
            position: absolute;
            width: 20px;
            height: 20px;
            left: -10px;
            background-color: white;
            top: 15px;
            border-radius: 50%;
            z-index: 1;
        }
        .timeline-item::after {
            content: '';
            position: absolute;
            width: 25px;
            height: 25px;
            right: -13px;
            background-color: var(--primary-color);
            border: 4px solid white;
            top: 15px;
            border-radius: 50%;
            z-index: 2;
        }
        .timeline-item:nth-child(even)::after {
            left: -13px;
        }
        .team-card {
            background: white;
            border-radius: var(--border-radius);
            overflow: hidden;
            box-shadow: var(--box-shadow);
            transition: var(--transition);
            margin-bottom: 2rem;
        }
        .team-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
        }
        .team-img {
            width: 100%;
            height: 250px;
            object-fit: cover;
        }
        .team-info {
            padding: 1.5rem;
            text-align: center;
        }
        .friendlink {
            background-color: #f8fafc;
            padding: 4rem 0;
        }
        .flink {
            display: inline-block;
            background: white;
            padding: 0.75rem 1.5rem;
            margin: 0.5rem;
            border-radius: var(--border-radius);
            border: 1px solid #e2e8f0;
            color: var(--dark-color);
            font-weight: 500;
            transition: var(--transition);
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
            transform: translateY(-3px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
        }
        footer {
            background-color: var(--dark-color);
            color: white;
            padding: 4rem 0 2rem;
        }
        footer h5 {
            color: white;
            margin-bottom: 1.5rem;
            position: relative;
            padding-bottom: 0.75rem;
        }
        footer h5:after {
            content: '';
            position: absolute;
            width: 40px;
            height: 3px;
            background: var(--primary-color);
            bottom: 0;
            left: 0;
            border-radius: 2px;
        }
        footer a {
            color: #cbd5e1;
            display: block;
            margin-bottom: 0.75rem;
        }
        footer a:hover {
            color: white;
            padding-left: 5px;
        }
        .social-icons a {
            display: inline-block;
            width: 40px;
            height: 40px;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 50%;
            text-align: center;
            line-height: 40px;
            margin-right: 0.75rem;
            transition: var(--transition);
        }
        .social-icons a:hover {
            background: var(--primary-color);
            transform: translateY(-5px);
        }
        .copyright {
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            padding-top: 2rem;
            margin-top: 3rem;
            text-align: center;
            color: #94a3b8;
            font-size: 0.9rem;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
            .hero-section {
                padding: 8rem 0 3rem;
            }
            .section-padding {
                padding: 3rem 0;
            }
            .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(odd) .timeline-content::after,
            .timeline-item:nth-child(even) .timeline-content::after {
                left: -10px;
                right: auto;
            }
        }
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        .fade-in-up {
            animation: fadeInUp 0.6s ease forwards;
        }
        .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;
            font-size: 1.5rem;
            cursor: pointer;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            z-index: 999;
            box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: var(--secondary-color);
            transform: translateY(-5px);
        }