:root {
            --primary-blue: #0056a6;
            --secondary-blue: #007bff;
            --industrial-dark: #2c3e50;
            --industrial-gray: #6c757d;
            --light-bg: #f8f9fa;
            --accent-red: #dc3545;
            --border-color: #dee2e6;
        }
        body {
            font-family: 'Microsoft YaHei', 'Segoe UI', Arial, sans-serif;
            color: #333;
            overflow-x: hidden;
            line-height: 1.6;
        }
        .navbar-brand img {
            max-height: 60px;
            transition: transform 0.3s ease;
        }
        .navbar-brand:hover img {
            transform: scale(1.05);
        }
        .hero-section {
            background: linear-gradient(rgba(0, 86, 166, 0.85), rgba(0, 86, 166, 0.9)), url('https://images.unsplash.com/photo-1581094794329-c8112a89af12?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 120px 0 80px;
        }
        .hero-section h1 {
            font-weight: 700;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
            margin-bottom: 1.5rem;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 3rem;
            color: var(--primary-blue);
            font-weight: 700;
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 80px;
            height: 4px;
            background-color: var(--accent-red);
        }
        .text-center .section-title:after {
            left: 50%;
            transform: translateX(-50%);
        }
        .card-hover {
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border: 1px solid var(--border-color);
            height: 100%;
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }
        .product-icon {
            font-size: 2.5rem;
            color: var(--primary-blue);
            margin-bottom: 1rem;
        }
        .btn-industrial {
            background-color: var(--primary-blue);
            border-color: var(--primary-blue);
            color: white;
            padding: 10px 25px;
            font-weight: 600;
            border-radius: 4px;
            transition: all 0.3s ease;
        }
        .btn-industrial:hover {
            background-color: #004085;
            border-color: #004085;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        .accordion-button {
            font-weight: 600;
            background-color: var(--light-bg);
        }
        .accordion-button:not(.collapsed) {
            color: var(--primary-blue);
            background-color: rgba(0, 86, 166, 0.05);
        }
        .contact-info-box {
            background: white;
            padding: 30px;
            border-radius: 8px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            border-top: 5px solid var(--primary-blue);
            height: 100%;
        }
        .flink {
            display: inline-block;
            padding: 8px 20px;
            margin: 5px 10px;
            background-color: var(--light-bg);
            border-radius: 30px;
            color: var(--industrial-dark);
            text-decoration: none;
            border: 1px solid var(--border-color);
            transition: all 0.3s ease;
        }
        .flink:hover {
            background-color: var(--primary-blue);
            color: white;
            transform: translateY(-3px);
            border-color: var(--primary-blue);
        }
        footer {
            background-color: var(--industrial-dark);
            color: #ddd;
        }
        footer a {
            color: #ddd;
            text-decoration: none;
            transition: color 0.3s ease;
        }
        footer a:hover {
            color: white;
            text-decoration: underline;
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--primary-blue);
            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 0.3s ease;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--accent-red);
            transform: scale(1.1);
        }
        .sticky-nav {
            position: sticky;
            top: 0;
            z-index: 1020;
            background-color: rgba(255, 255, 255, 0.98);
            box-shadow: 0 2px 10px rgba(0,0,0,0.05);
            transition: all 0.3s ease;
        }
        .company-intro-img {
            border-radius: 8px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 80px 0 40px;
            }
            .hero-section h1 {
                font-size: 2rem;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }