:root {
            --primary-color: #0d6efd;
            --secondary-color: #6c757d;
            --accent-color: #20c997;
            --dark-color: #212529;
            --light-color: #f8f9fa;
            --shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            --transition: all 0.3s ease;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            line-height: 1.8;
            color: #333;
            overflow-x: hidden;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .nav-link {
            font-weight: 500;
            padding: 0.5rem 1.2rem !important;
            transition: var(--transition);
        }
        .nav-link:hover {
            color: var(--primary-color) !important;
            transform: translateY(-2px);
        }
        .hero-section {
            background: linear-gradient(rgba(13, 110, 253, 0.85), rgba(32, 201, 151, 0.8)), url('https://images.unsplash.com/photo-1552664730-d307ca884978?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 180px 0 120px;
            position: relative;
        }
        .hero-section h1 {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            text-shadow: 2px 2px 5px rgba(0,0,0,0.2);
        }
        @media (max-width: 768px) {
            .hero-section h1 { font-size: 2.5rem; }
            .hero-section { padding: 120px 0 80px; }
        }
        .section-title {
            position: relative;
            padding-bottom: 20px;
            margin-bottom: 50px;
            text-align: center;
            font-weight: 700;
            color: var(--dark-color);
        }
        .section-title:after {
            content: '';
            position: absolute;
            width: 80px;
            height: 4px;
            background: var(--accent-color);
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
        }
        .card-hover {
            transition: var(--transition);
            border: none;
            box-shadow: var(--shadow);
            height: 100%;
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }
        .service-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 1.5rem;
            display: inline-block;
            transition: var(--transition);
        }
        .card-hover:hover .service-icon {
            transform: scale(1.1);
            color: var(--accent-color);
        }
        .btn-primary {
            background-color: var(--primary-color);
            border: none;
            padding: 12px 30px;
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: #0b5ed7;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(13, 110, 253, 0.3);
        }
        .partner-logo {
            filter: grayscale(100%);
            opacity: 0.7;
            transition: var(--transition);
        }
        .partner-logo:hover {
            filter: grayscale(0);
            opacity: 1;
            transform: scale(1.05);
        }
        .flink {
            background: var(--light-color);
            padding: 12px 20px;
            border-radius: 8px;
            color: var(--dark-color);
            text-decoration: none;
            display: inline-block;
            margin: 5px 10px;
            transition: var(--transition);
            border: 1px solid #dee2e6;
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-3px);
            border-color: var(--primary-color);
        }
        footer {
            background: var(--dark-color);
            color: #adb5bd;
        }
        footer a {
            color: #adb5bd;
            text-decoration: none;
            transition: var(--transition);
        }
        footer a:hover {
            color: white;
            padding-left: 5px;
        }
        .social-icon {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            background: rgba(255,255,255,0.1);
            border-radius: 50%;
            margin-right: 10px;
            transition: var(--transition);
        }
        .social-icon:hover {
            background: var(--primary-color);
            transform: translateY(-5px);
        }
        .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: 1.2rem;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: var(--accent-color);
            transform: translateY(-5px);
        }
        .timeline-item {
            position: relative;
            padding-left: 40px;
            margin-bottom: 40px;
        }
        .timeline-item:before {
            content: '';
            position: absolute;
            left: 0;
            top: 8px;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            background: var(--accent-color);
            border: 4px solid white;
            box-shadow: 0 0 0 3px var(--accent-color);
        }
        .timeline-item:after {
            content: '';
            position: absolute;
            left: 9px;
            top: 28px;
            width: 2px;
            height: calc(100% + 12px);
            background: #dee2e6;
        }
        .timeline-item:last-child:after {
            display: none;
        }
        .stats-number {
            font-size: 3rem;
            font-weight: 800;
            color: var(--primary-color);
            display: block;
            line-height: 1;
        }
        .stats-label {
            font-size: 1rem;
            color: var(--secondary-color);
            text-transform: uppercase;
            letter-spacing: 1px;
        }
        .form-control:focus {
            border-color: var(--accent-color);
            box-shadow: 0 0 0 0.25rem rgba(32, 201, 151, 0.25);
        }
        .testimonial-card {
            background: white;
            border-radius: 15px;
            padding: 30px;
            box-shadow: var(--shadow);
            height: 100%;
            border-top: 5px solid var(--primary-color);
        }
        .testimonial-avatar {
            width: 70px;
            height: 70px;
            border-radius: 50%;
            object-fit: cover;
            border: 4px solid var(--light-color);
        }