:root {
            --primary: #1a5f7a;
            --secondary: #2d9cdb;
            --accent: #ff7b00;
            --light: #f8f9fa;
            --dark: #343a40;
        }
        body {
            font-family: "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
            color: #333;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5, h6 {
            font-weight: 600;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.97);
            box-shadow: 0 2px 15px rgba(0, 0, 0, 0.08);
            padding-top: 0.8rem;
            padding-bottom: 0.8rem;
            transition: all 0.3s ease;
        }
        .navbar-brand {
            font-weight: 700;
            color: var(--primary) !important;
            font-size: 1.8rem;
        }
        .nav-link {
            font-weight: 500;
            margin: 0 0.5rem;
            color: var(--dark) !important;
            transition: color 0.3s;
            position: relative;
        }
        .nav-link:hover, .nav-link.active {
            color: var(--primary) !important;
        }
        .nav-link::after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            bottom: 0;
            left: 50%;
            background-color: var(--accent);
            transition: all 0.3s ease;
            transform: translateX(-50%);
        }
        .nav-link:hover::after, .nav-link.active::after {
            width: 80%;
        }
        .hero {
            background: linear-gradient(135deg, rgba(26, 95, 122, 0.9) 0%, rgba(45, 156, 219, 0.85) 100%), url('https://images.unsplash.com/photo-1551288049-bebda4e38f71?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80') center/cover no-repeat;
            color: white;
            padding: 8rem 0 6rem;
            min-height: 90vh;
            display: flex;
            align-items: center;
        }
        .hero h1 {
            font-size: 3.5rem;
            margin-bottom: 1.5rem;
            text-shadow: 1px 1px 3px rgba(0,0,0,0.3);
        }
        .hero p {
            font-size: 1.3rem;
            margin-bottom: 2.5rem;
            max-width: 700px;
        }
        .btn-primary {
            background-color: var(--accent);
            border-color: var(--accent);
            padding: 0.8rem 2.5rem;
            font-weight: 600;
            border-radius: 50px;
            transition: all 0.3s;
        }
        .btn-primary:hover {
            background-color: #e56c00;
            border-color: #e56c00;
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(255, 123, 0, 0.3);
        }
        .btn-outline-light {
            border-radius: 50px;
            padding: 0.8rem 2.5rem;
            font-weight: 600;
            transition: all 0.3s;
        }
        .btn-outline-light:hover {
            background-color: white;
            color: var(--primary);
            transform: translateY(-3px);
        }
        .section-title {
            text-align: center;
            margin-bottom: 4rem;
            position: relative;
        }
        .section-title h2 {
            color: var(--primary);
            display: inline-block;
            padding-bottom: 1rem;
        }
        .section-title h2::after {
            content: '';
            position: absolute;
            width: 80px;
            height: 4px;
            background-color: var(--accent);
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
        }
        .icon-box {
            background: white;
            padding: 2.5rem 2rem;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
            height: 100%;
            transition: transform 0.3s, box-shadow 0.3s;
            border-top: 4px solid var(--secondary);
        }
        .icon-box:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
        }
        .icon-box i {
            font-size: 3rem;
            color: var(--secondary);
            margin-bottom: 1.5rem;
        }
        .service-img {
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
            transition: transform 0.5s;
        }
        .service-img:hover {
            transform: scale(1.03);
        }
        .stats {
            background: linear-gradient(to right, var(--primary), var(--secondary));
            color: white;
            padding: 5rem 0;
        }
        .stat-number {
            font-size: 3.5rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
        }
        .case-study-card {
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
            transition: all 0.3s;
            height: 100%;
        }
        .case-study-card:hover {
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
            transform: translateY(-10px);
        }
        .case-study-card img {
            height: 220px;
            object-fit: cover;
            transition: transform 0.5s;
        }
        .case-study-card:hover img {
            transform: scale(1.05);
        }
        .news-card {
            border-left: 4px solid var(--secondary);
            padding-left: 1.5rem;
            margin-bottom: 2rem;
            transition: border-color 0.3s;
        }
        .news-card:hover {
            border-left-color: var(--accent);
        }
        .news-date {
            color: var(--secondary);
            font-weight: 600;
            font-size: 0.9rem;
        }
        .contact-info-box {
            background: white;
            padding: 2rem;
            border-radius: 15px;
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
            text-align: center;
            height: 100%;
            border-bottom: 4px solid var(--primary);
        }
        .contact-info-box i {
            font-size: 2.5rem;
            color: var(--primary);
            margin-bottom: 1.5rem;
        }
        .contact-form {
            background: white;
            padding: 3rem;
            border-radius: 15px;
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.08);
        }
        .form-control, .form-select {
            padding: 0.8rem 1rem;
            border-radius: 10px;
            border: 1px solid #ddd;
            transition: all 0.3s;
        }
        .form-control:focus, .form-select:focus {
            border-color: var(--secondary);
            box-shadow: 0 0 0 0.25rem rgba(45, 156, 219, 0.25);
        }
        footer {
            background-color: #2c3e50;
            color: #ecf0f1;
            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;
            width: 50px;
            height: 2px;
            background-color: var(--accent);
            bottom: 0;
            left: 0;
        }
        .footer-links ul {
            list-style: none;
            padding-left: 0;
        }
        .footer-links li {
            margin-bottom: 0.8rem;
        }
        .footer-links a {
            color: #bdc3c7;
            text-decoration: none;
            transition: color 0.3s, padding-left 0.3s;
        }
        .footer-links a:hover {
            color: white;
            padding-left: 5px;
        }
        .copyright {
            background-color: #1a252f;
            padding: 1.5rem 0;
            margin-top: 3rem;
            font-size: 0.9rem;
            color: #95a5a6;
        }
        .friendlink {
            padding: 4rem 0;
            background-color: #f8f9fa;
            border-top: 1px solid #eee;
            border-bottom: 1px solid #eee;
        }
        .flink {
            display: inline-block;
            background: white;
            padding: 1rem 2rem;
            margin: 0.5rem;
            border-radius: 10px;
            color: var(--dark);
            text-decoration: none;
            border: 1px solid #e0e0e0;
            transition: all 0.3s;
            font-weight: 500;
        }
        .flink:hover {
            background-color: var(--primary);
            color: white;
            border-color: var(--primary);
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(26, 95, 122, 0.2);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--accent);
            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: all 0.3s;
            z-index: 1000;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--primary);
            color: white;
        }
        @media (max-width: 768px) {
            .hero h1 {
                font-size: 2.5rem;
            }
            .hero p {
                font-size: 1.1rem;
            }
            .section-title h2 {
                font-size: 2rem;
            }
            .stat-number {
                font-size: 2.5rem;
            }
            .contact-form {
                padding: 2rem;
            }
        }