:root {
            --primary-color: #0056b3;
            --secondary-color: #ffc107;
            --dark-color: #212529;
            --light-color: #f8f9fa;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
            color: #333;
            overflow-x: hidden;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
        }
        .navbar-brand span {
            color: var(--primary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(0, 30, 60, 0.85), rgba(0, 30, 60, 0.9)), url('https://images.unsplash.com/photo-1581094794329-c8112a89af12?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80') center/cover no-repeat;
            color: white;
            padding: 120px 0 80px;
            position: relative;
        }
        .section-title {
            position: relative;
            margin-bottom: 3rem;
            padding-bottom: 1rem;
        }
        .section-title:after {
            content: '';
            position: absolute;
            left: 0;
            bottom: 0;
            width: 60px;
            height: 4px;
            background-color: var(--secondary-color);
        }
        .text-center .section-title:after {
            left: 50%;
            transform: translateX(-50%);
        }
        .card {
            border: none;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
            transition: var(--transition);
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .card-img-top {
            height: 220px;
            object-fit: cover;
            transition: var(--transition);
        }
        .card:hover .card-img-top {
            transform: scale(1.05);
        }
        .icon-box {
            width: 70px;
            height: 70px;
            background-color: var(--primary-color);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
            color: white;
            font-size: 1.8rem;
        }
        .process-step {
            position: relative;
            padding-left: 30px;
            margin-bottom: 2rem;
        }
        .process-step:before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            width: 2px;
            height: 100%;
            background-color: var(--primary-color);
        }
        .step-number {
            position: absolute;
            left: -15px;
            top: 0;
            width: 30px;
            height: 30px;
            background-color: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
        }
        .product-category {
            margin-bottom: 4rem;
        }
        .category-title {
            border-left: 5px solid var(--primary-color);
            padding-left: 15px;
            margin-bottom: 2rem;
        }
        .table-specs th {
            background-color: var(--light-color);
            font-weight: 600;
        }
        .contact-info-box {
            background-color: var(--light-color);
            padding: 2rem;
            border-radius: 10px;
            height: 100%;
            border-left: 5px solid var(--primary-color);
        }
        .contact-icon {
            width: 50px;
            height: 50px;
            background-color: var(--primary-color);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 1.5rem;
            margin-bottom: 1rem;
        }
        footer {
            background-color: var(--dark-color);
            color: white;
            padding-top: 3rem;
        }
        .footer-links h5 {
            border-bottom: 2px solid var(--secondary-color);
            padding-bottom: 0.5rem;
            margin-bottom: 1.5rem;
        }
        .footer-links ul {
            list-style: none;
            padding-left: 0;
        }
        .footer-links li {
            margin-bottom: 0.7rem;
        }
        .footer-links a {
            color: #ccc;
            text-decoration: none;
            transition: var(--transition);
        }
        .footer-links a:hover {
            color: var(--secondary-color);
            padding-left: 5px;
        }
        .friendlink {
            background-color: #2c3e50;
            padding: 2rem 0;
            border-top: 1px solid #444;
        }
        .flink {
            display: inline-block;
            background-color: rgba(255,255,255,0.1);
            color: #ddd;
            padding: 8px 15px;
            margin: 5px 10px;
            border-radius: 5px;
            text-decoration: none;
            transition: var(--transition);
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            transform: translateY(-3px);
        }
        .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;
            text-decoration: none;
            font-size: 1.5rem;
            z-index: 1000;
            opacity: 0;
            transition: var(--transition);
        }
        .back-to-top.show {
            opacity: 1;
        }
        .back-to-top:hover {
            background-color: var(--secondary-color);
            color: var(--dark-color);
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 100px 0 60px;
            }
            .display-4 {
                font-size: 2.2rem;
            }
            .section-title {
                margin-bottom: 2rem;
            }
        }