:root {
            --primary-color: #1a56db;
            --secondary-color: #0e9f6e;
            --accent-color: #ff5a1f;
            --dark-color: #1f2937;
            --light-color: #f9fafb;
            --text-color: #374151;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: var(--text-color);
            line-height: 1.7;
        }
        h1, h2, h3, h4, h5, h6 {
            font-weight: 700;
            color: var(--dark-color);
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
            padding: 1rem 0;
            transition: all 0.3s ease;
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color);
        }
        .nav-link {
            font-weight: 500;
            margin: 0 0.5rem;
            color: var(--dark-color);
            transition: color 0.3s;
        }
        .nav-link:hover {
            color: var(--primary-color);
        }
        .hero-section {
            background: linear-gradient(135deg, rgba(26, 86, 219, 0.9) 0%, rgba(14, 159, 110, 0.85) 100%), url('https://images.unsplash.com/photo-1523050854058-8df90110c9f1?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80') center/cover no-repeat;
            color: white;
            padding: 8rem 0 6rem;
        }
        .hero-title {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
        }
        .section-padding {
            padding: 6rem 0;
        }
        .section-title {
            position: relative;
            margin-bottom: 3.5rem;
            font-size: 2.5rem;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: -12px;
            left: 0;
            width: 70px;
            height: 4px;
            background-color: var(--accent-color);
        }
        .text-center .section-title::after {
            left: 50%;
            transform: translateX(-50%);
        }
        .card {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
            transition: transform 0.4s ease, box-shadow 0.4s ease;
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 12px 28px rgba(0, 0, 0, 0.15);
        }
        .service-icon {
            width: 70px;
            height: 70px;
            background: linear-gradient(135deg, var(--primary-color), #3f83f8);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1.5rem;
            color: white;
            font-size: 1.8rem;
        }
        .stat-number {
            font-size: 3rem;
            font-weight: 800;
            color: var(--primary-color);
            margin-bottom: 0.5rem;
        }
        .stat-label {
            font-size: 1.1rem;
            color: var(--text-color);
            font-weight: 500;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            border-radius: 8px;
            transition: all 0.3s;
        }
        .btn-primary:hover {
            background-color: #1e40af;
            border-color: #1e40af;
            transform: translateY(-2px);
        }
        .btn-secondary {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            border-radius: 8px;
            transition: all 0.3s;
        }
        .btn-secondary:hover {
            background-color: #0c7c5d;
            border-color: #0c7c5d;
            transform: translateY(-2px);
        }
        .testimonial-card {
            background-color: var(--light-color);
            border-left: 5px solid var(--primary-color);
            padding: 2rem;
            border-radius: 0 10px 10px 0;
        }
        .client-logo {
            height: 60px;
            filter: grayscale(100%);
            opacity: 0.7;
            transition: all 0.3s;
        }
        .client-logo:hover {
            filter: grayscale(0);
            opacity: 1;
        }
        .footer {
            background-color: var(--dark-color);
            color: #d1d5db;
            padding: 4rem 0 2rem;
        }
        .footer-title {
            color: white;
            font-size: 1.3rem;
            margin-bottom: 1.5rem;
            position: relative;
            padding-bottom: 0.8rem;
        }
        .footer-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 40px;
            height: 3px;
            background-color: var(--accent-color);
        }
        .footer-link {
            color: #d1d5db;
            text-decoration: none;
            display: block;
            margin-bottom: 0.8rem;
            transition: color 0.3s;
        }
        .footer-link:hover {
            color: white;
            padding-left: 5px;
        }
        .copyright {
            border-top: 1px solid #374151;
            padding-top: 2rem;
            margin-top: 3rem;
            text-align: center;
            font-size: 0.9rem;
            color: #9ca3af;
        }
        .flink {
            display: inline-block;
            background-color: rgba(255, 255, 255, 0.1);
            color: #d1d5db;
            padding: 0.5rem 1.2rem;
            border-radius: 30px;
            margin: 0.3rem;
            text-decoration: none;
            transition: all 0.3s;
            font-size: 0.9rem;
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            transform: translateY(-3px);
        }
        .contact-info {
            background-color: var(--light-color);
            padding: 3rem;
            border-radius: 12px;
        }
        .contact-icon {
            width: 50px;
            height: 50px;
            background-color: rgba(26, 86, 219, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--primary-color);
            font-size: 1.2rem;
            margin-right: 1rem;
        }
        .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: 1.2rem;
            text-decoration: none;
            box-shadow: 0 4px 12px rgba(26, 86, 219, 0.3);
            z-index: 100;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: #1e40af;
            transform: translateY(-3px);
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.5rem;
            }
            .section-padding {
                padding: 4rem 0;
            }
            .section-title {
                font-size: 2rem;
            }
            .navbar {
                padding: 0.8rem 0;
            }
            .contact-info {
                padding: 2rem;
            }
        }