: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;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            color: var(--dark-color);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .navbar-nav .nav-link {
            font-weight: 500;
            padding: 0.5rem 1.2rem !important;
            transition: color var(--transition-speed);
        }
        .navbar-nav .nav-link:hover {
            color: var(--primary-color) !important;
        }
        .hero-section {
            background: linear-gradient(135deg, rgba(0, 86, 179, 0.9) 0%, rgba(23, 162, 184, 0.8) 100%), url('https://images.unsplash.com/photo-1497366216548-37526070297c?ixlib=rb-4.0.3&auto=format&fit=crop&w=1600&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 120px 0;
            position: relative;
        }
        .hero-section h1 {
            color: white;
            font-size: 3.5rem;
            margin-bottom: 1.5rem;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
        }
        .section-title {
            position: relative;
            margin-bottom: 3rem;
            padding-bottom: 1rem;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 80px;
            height: 4px;
            background: var(--primary-color);
            border-radius: 2px;
        }
        .section-title.text-center::after {
            left: 50%;
            transform: translateX(-50%);
        }
        .card {
            border: none;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
            transition: transform var(--transition-speed), box-shadow var(--transition-speed);
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .icon-box {
            width: 70px;
            height: 70px;
            background: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1.5rem;
            font-size: 1.8rem;
        }
        .service-card {
            border-top: 4px solid var(--primary-color);
            padding-top: 2rem;
        }
        .stats-box {
            text-align: center;
            padding: 2rem;
            background: white;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
        }
        .stats-number {
            font-size: 3rem;
            font-weight: 800;
            color: var(--primary-color);
            line-height: 1;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            transition: all var(--transition-speed);
        }
        .btn-primary:hover {
            background-color: #004494;
            border-color: #004494;
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0,86,179,0.3);
        }
        .contact-info-box {
            background: var(--light-color);
            padding: 2rem;
            border-radius: 10px;
            border-left: 5px solid var(--primary-color);
            margin-bottom: 2rem;
        }
        .footer {
            background-color: var(--dark-color);
            color: rgba(255,255,255,0.8);
            padding: 4rem 0 2rem;
        }
        .footer a {
            color: rgba(255,255,255,0.8);
            text-decoration: none;
            transition: color var(--transition-speed);
        }
        .footer a:hover {
            color: white;
        }
        .copyright {
            border-top: 1px solid rgba(255,255,255,0.1);
            padding-top: 1.5rem;
            margin-top: 3rem;
            font-size: 0.9rem;
            color: rgba(255,255,255,0.6);
        }
        .flink {
            display: inline-block;
            padding: 0.5rem 1.5rem;
            margin: 0.5rem;
            background: rgba(255,255,255,0.1);
            border-radius: 50px;
            transition: all var(--transition-speed);
            color: white;
            text-decoration: none;
        }
        .flink:hover {
            background: var(--primary-color);
            transform: translateY(-3px);
            color: white;
        }
        .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: all var(--transition-speed);
            text-decoration: none;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: #004494;
            color: white;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
            .hero-section {
                padding: 80px 0;
            }
            .section-title {
                font-size: 1.8rem;
            }
            .stats-number {
                font-size: 2.5rem;
            }
        }
        @media (max-width: 576px) {
            .hero-section h1 {
                font-size: 2rem;
            }
            .navbar-brand {
                font-size: 1.5rem;
            }
        }
        .img-fluid {
            border-radius: 8px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        .timeline {
            position: relative;
            padding-left: 30px;
        }
        .timeline::before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            bottom: 0;
            width: 4px;
            background: var(--primary-color);
        }
        .timeline-item {
            position: relative;
            margin-bottom: 2.5rem;
        }
        .timeline-item::before {
            content: '';
            position: absolute;
            left: -38px;
            top: 5px;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            background: white;
            border: 4px solid var(--primary-color);
        }
        .fade-in {
            opacity: 0;
            transform: translateY(30px);
            transition: opacity 0.8s, transform 0.8s;
        }
        .fade-in.visible {
            opacity: 1;
            transform: translateY(0);
        }