:root {
            --primary-color: #1a5f7a;
            --secondary-color: #159895;
            --accent-color: #57c5b6;
            --light-color: #f8f9fa;
            --dark-color: #343a40;
            --gray-color: #6c757d;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            line-height: 1.8;
            color: #333;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5, h6 {
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .text-primary { color: var(--primary-color) !important; }
        .bg-primary { background-color: var(--primary-color) !important; }
        .btn-primary { 
            background-color: var(--primary-color);
            border-color: var(--primary-color);
        }
        .btn-primary:hover {
            background-color: #0d4b63;
            border-color: #0d4b63;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
            padding: 1rem 0;
            transition: var(--transition);
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .navbar-nav .nav-link {
            font-weight: 600;
            padding: 0.5rem 1.2rem !important;
            color: var(--dark-color) !important;
            transition: var(--transition);
        }
        .navbar-nav .nav-link:hover, 
        .navbar-nav .nav-link.active {
            color: var(--primary-color) !important;
        }
        .hero-section {
            background: linear-gradient(rgba(26, 95, 122, 0.85), rgba(21, 152, 149, 0.8)), 
                        url('https://images.unsplash.com/photo-1531973576160-7125cd663d86?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80') no-repeat center center;
            background-size: cover;
            color: white;
            padding: 10rem 0 8rem;
            position: relative;
        }
        .hero-section h1 {
            color: white;
            font-size: 3.5rem;
            margin-bottom: 1.5rem;
            text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.3);
        }
        .hero-section p {
            font-size: 1.3rem;
            max-width: 700px;
            margin: 0 auto 2rem;
        }
        .section-padding {
            padding: 6rem 0;
        }
        .section-title {
            position: relative;
            padding-bottom: 1rem;
            margin-bottom: 3rem;
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--accent-color);
            border-radius: 2px;
        }
        .card-hover {
            transition: var(--transition);
            height: 100%;
            border: none;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            border-radius: 12px;
            overflow: hidden;
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }
        .service-icon {
            width: 80px;
            height: 80px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            color: white;
            font-size: 2rem;
        }
        .about-img {
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
        }
        .stats-box {
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            color: white;
            padding: 2.5rem 1.5rem;
            border-radius: 15px;
            text-align: center;
            margin-top: 2rem;
        }
        .stats-box .number {
            font-size: 3rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
            display: block;
        }
        .stats-box .label {
            font-size: 1.1rem;
            opacity: 0.9;
        }
        .timeline {
            position: relative;
            padding-left: 3rem;
            margin-top: 3rem;
        }
        .timeline:before {
            content: '';
            position: absolute;
            left: 15px;
            top: 0;
            bottom: 0;
            width: 3px;
            background: linear-gradient(to bottom, var(--primary-color), var(--accent-color));
        }
        .timeline-item {
            position: relative;
            margin-bottom: 2.5rem;
        }
        .timeline-item:before {
            content: '';
            position: absolute;
            left: -3rem;
            top: 5px;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            background-color: var(--primary-color);
            border: 4px solid white;
            box-shadow: 0 0 0 3px var(--primary-color);
        }
        .client-logo {
            filter: grayscale(100%);
            opacity: 0.7;
            transition: var(--transition);
            max-height: 60px;
            width: auto;
        }
        .client-logo:hover {
            filter: grayscale(0);
            opacity: 1;
        }
        .contact-info-box {
            background-color: white;
            padding: 2rem;
            border-radius: 12px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            text-align: center;
            height: 100%;
            transition: var(--transition);
        }
        .contact-info-box:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.12);
        }
        .contact-icon {
            width: 70px;
            height: 70px;
            background-color: rgba(26, 95, 122, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            color: var(--primary-color);
            font-size: 1.8rem;
        }
        footer {
            background-color: #1a252f;
            color: rgba(255, 255, 255, 0.8);
            padding-top: 4rem;
        }
        .footer-links h5 {
            color: white;
            margin-bottom: 1.5rem;
            position: relative;
            padding-bottom: 0.8rem;
        }
        .footer-links h5:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 40px;
            height: 3px;
            background-color: var(--accent-color);
        }
        .footer-links ul li {
            margin-bottom: 0.8rem;
        }
        .footer-links ul li a {
            color: rgba(255, 255, 255, 0.7);
            text-decoration: none;
            transition: var(--transition);
        }
        .footer-links ul li a:hover {
            color: var(--accent-color);
            padding-left: 5px;
        }
        .friendlink {
            background-color: rgba(255, 255, 255, 0.05);
            border-radius: 10px;
            padding: 2rem;
            margin-top: 2rem;
        }
        .flink {
            display: inline-block;
            background-color: rgba(255, 255, 255, 0.08);
            color: rgba(255, 255, 255, 0.8);
            padding: 0.6rem 1.2rem;
            border-radius: 6px;
            margin: 0.5rem;
            text-decoration: none;
            transition: var(--transition);
            border: 1px solid rgba(255, 255, 255, 0.1);
        }
        .flink:hover {
            background-color: rgba(255, 255, 255, 0.15);
            color: white;
            transform: translateY(-3px);
        }
        .copyright {
            background-color: rgba(0, 0, 0, 0.2);
            padding: 1.5rem 0;
            margin-top: 3rem;
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.6);
        }
        .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;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            z-index: 999;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--secondary-color);
            color: white;
        }
        @media (max-width: 992px) {
            .hero-section h1 {
                font-size: 2.8rem;
            }
            .section-padding {
                padding: 4rem 0;
            }
            .hero-section {
                padding: 8rem 0 6rem;
            }
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.3rem;
            }
            .navbar-nav {
                padding-top: 1rem;
            }
            .stats-box {
                margin-bottom: 1.5rem;
            }
        }
        @media (max-width: 576px) {
            .hero-section {
                padding: 6rem 0 4rem;
            }
            .hero-section h1 {
                font-size: 2rem;
            }
            .section-padding {
                padding: 3rem 0;
            }
        }
        .fade-in {
            animation: fadeIn 1s ease-in-out;
        }
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }
        .sticky-nav {
            background-color: rgba(255, 255, 255, 0.98);
            padding: 0.7rem 0;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
        }