:root {
            --primary-color: #1a365d;
            --secondary-color: #2d6bc2;
            --accent-color: #e63946;
            --light-color: #f8f9fa;
            --dark-color: #212529;
            --gray-color: #6c757d;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: var(--dark-color);
            line-height: 1.8;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5, h6 {
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
            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: 600;
            color: var(--dark-color);
            margin: 0 0.5rem;
            transition: color 0.3s;
        }
        .nav-link:hover {
            color: var(--secondary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(26, 54, 93, 0.85), rgba(26, 54, 93, 0.9)), url('https://images.unsplash.com/photo-1556742049-0cfed4f6a45d?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') no-repeat center center/cover;
            color: white;
            padding: 8rem 0 6rem;
            min-height: 85vh;
            display: flex;
            align-items: center;
        }
        .hero-title {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            color: white;
        }
        .section-padding {
            padding: 5rem 0;
        }
        .section-title {
            position: relative;
            padding-bottom: 1rem;
            margin-bottom: 3rem;
            text-align: center;
        }
        .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 {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
        }
        .card-img-top {
            height: 220px;
            object-fit: cover;
        }
        .icon-box {
            width: 70px;
            height: 70px;
            background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1.5rem;
            color: white;
            font-size: 1.8rem;
        }
        .btn-primary {
            background-color: var(--secondary-color);
            border: none;
            padding: 0.8rem 2rem;
            border-radius: 30px;
            font-weight: 600;
            transition: all 0.3s;
        }
        .btn-primary:hover {
            background-color: var(--primary-color);
            transform: translateY(-3px);
            box-shadow: 0 7px 15px rgba(26, 54, 93, 0.2);
        }
        .flink {
            display: inline-block;
            padding: 0.5rem 1.5rem;
            margin: 0.5rem;
            background-color: var(--light-color);
            border-radius: 30px;
            color: var(--dark-color);
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s;
            border: 1px solid #dee2e6;
        }
        .flink:hover {
            background-color: var(--secondary-color);
            color: white;
            transform: translateY(-3px);
        }
        .footer {
            background-color: var(--primary-color);
            color: white;
            padding: 4rem 0 2rem;
        }
        .footer a {
            color: #cbd5e0;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer a:hover {
            color: white;
        }
        .contact-info li {
            margin-bottom: 0.8rem;
            display: flex;
            align-items: center;
        }
        .contact-info i {
            width: 25px;
            color: var(--secondary-color);
            margin-right: 10px;
        }
        .product-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: 2rem;
        }
        .stat-box {
            text-align: center;
            padding: 2rem;
            background-color: white;
            border-radius: 12px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
        }
        .stat-number {
            font-size: 3rem;
            font-weight: 800;
            color: var(--secondary-color);
            line-height: 1;
        }
        .timeline {
            position: relative;
            padding-left: 2rem;
        }
        .timeline:before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            bottom: 0;
            width: 3px;
            background-color: var(--secondary-color);
        }
        .timeline-item {
            position: relative;
            margin-bottom: 2.5rem;
            padding-left: 1.5rem;
        }
        .timeline-item:before {
            content: '';
            position: absolute;
            left: -2.3rem;
            top: 0.5rem;
            width: 15px;
            height: 15px;
            border-radius: 50%;
            background-color: var(--accent-color);
            border: 3px solid white;
            box-shadow: 0 0 0 3px var(--secondary-color);
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.5rem;
            }
            .section-padding {
                padding: 3rem 0;
            }
            .navbar-nav {
                text-align: center;
                padding-top: 1rem;
            }
        }
        .map-container {
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
            height: 400px;
        }
        .accordion-button:not(.collapsed) {
            background-color: rgba(45, 107, 194, 0.1);
            color: var(--primary-color);
        }
        .form-control, .form-select {
            padding: 0.8rem 1rem;
            border-radius: 8px;
            border: 1px solid #ced4da;
        }
        .form-control:focus, .form-select:focus {
            border-color: var(--secondary-color);
            box-shadow: 0 0 0 0.25rem rgba(45, 107, 194, 0.25);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--secondary-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: all 0.3s;
            z-index: 1000;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--primary-color);
            color: white;
        }