:root {
            --primary-color: #c62828;
            --secondary-color: #212121;
            --accent-color: #ff6f00;
            --light-color: #f5f5f5;
            --dark-color: #1a1a1a;
            --text-color: #333;
            --text-light: #666;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: var(--text-color);
            line-height: 1.6;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5, h6 {
            font-weight: 700;
            color: var(--secondary-color);
            margin-bottom: 1rem;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            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(--primary-color);
        }
        .section-title.left:after {
            left: 0;
            transform: none;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 10px 25px;
            font-weight: 600;
            transition: all 0.3s ease;
        }
        .btn-primary:hover {
            background-color: #b71c1c;
            border-color: #b71c1c;
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(198, 40, 40, 0.2);
        }
        .btn-outline-primary {
            color: var(--primary-color);
            border-color: var(--primary-color);
        }
        .btn-outline-primary:hover {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
        }
        .navbar-brand {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--primary-color) !important;
        }
        .navbar-brand span {
            color: var(--secondary-color);
        }
        .navbar {
            padding: 15px 0;
            transition: all 0.3s ease;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
        .navbar.scrolled {
            padding: 10px 0;
            background-color: rgba(255, 255, 255, 0.95) !important;
            backdrop-filter: blur(10px);
        }
        .nav-link {
            font-weight: 600;
            color: var(--secondary-color) !important;
            margin: 0 5px;
            transition: all 0.3s ease;
            position: relative;
        }
        .nav-link:hover, .nav-link.active {
            color: var(--primary-color) !important;
        }
        .nav-link:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background-color: var(--primary-color);
            transition: width 0.3s ease;
        }
        .nav-link:hover:after, .nav-link.active:after {
            width: 100%;
        }
        .hero {
            background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('https://images.unsplash.com/photo-1621905252507-b35492cc74b4?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') no-repeat center center/cover;
            height: 100vh;
            min-height: 700px;
            color: white;
            display: flex;
            align-items: center;
            position: relative;
        }
        .hero-content {
            max-width: 800px;
        }
        .hero h1 {
            font-size: 3.5rem;
            color: white;
            margin-bottom: 1.5rem;
            text-shadow: 0 2px 10px rgba(0,0,0,0.3);
        }
        .hero p {
            font-size: 1.2rem;
            margin-bottom: 2rem;
        }
        .hero .btn {
            margin-right: 15px;
            margin-bottom: 10px;
        }
        .stat-item {
            text-align: center;
            padding: 30px 15px;
            border-radius: 10px;
            background-color: white;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: all 0.3s ease;
            margin-bottom: 30px;
        }
        .stat-item:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .stat-icon {
            width: 70px;
            height: 70px;
            background-color: rgba(198, 40, 40, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
            color: var(--primary-color);
            font-size: 1.8rem;
        }
        .stat-number {
            font-size: 2.5rem;
            font-weight: 800;
            color: var(--primary-color);
            margin-bottom: 5px;
        }
        .product-card {
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: all 0.3s ease;
            height: 100%;
            background-color: white;
        }
        .product-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .product-img {
            height: 250px;
            width: 100%;
            object-fit: cover;
        }
        .product-body {
            padding: 25px;
        }
        .product-title {
            font-size: 1.3rem;
            margin-bottom: 15px;
            color: var(--secondary-color);
        }
        .product-features {
            list-style: none;
            padding-left: 0;
            margin-bottom: 20px;
        }
        .product-features li {
            margin-bottom: 8px;
            color: var(--text-light);
        }
        .product-features li i {
            color: var(--primary-color);
            margin-right: 10px;
        }
        .certificate-item {
            padding: 20px;
            border-radius: 10px;
            background-color: white;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            text-align: center;
            height: 100%;
            transition: all 0.3s ease;
        }
        .certificate-item:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }
        .certificate-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 20px;
        }
        .news-card {
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: all 0.3s ease;
            height: 100%;
            background-color: white;
        }
        .news-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }
        .news-img {
            height: 200px;
            width: 100%;
            object-fit: cover;
        }
        .news-body {
            padding: 25px;
        }
        .news-date {
            color: var(--primary-color);
            font-size: 0.9rem;
            font-weight: 600;
            margin-bottom: 10px;
        }
        .news-title {
            font-size: 1.2rem;
            margin-bottom: 15px;
            color: var(--secondary-color);
        }
        .contact-info {
            padding: 30px;
            border-radius: 10px;
            background-color: white;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            height: 100%;
        }
        .contact-icon {
            width: 60px;
            height: 60px;
            background-color: rgba(198, 40, 40, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
            color: var(--primary-color);
            font-size: 1.5rem;
        }
        .contact-title {
            font-size: 1.2rem;
            margin-bottom: 15px;
        }
        .contact-detail {
            color: var(--text-light);
        }
        .contact-form {
            padding: 40px;
            border-radius: 10px;
            background-color: white;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
        }
        .form-control, .form-select {
            padding: 12px 15px;
            border-radius: 5px;
            border: 1px solid #ddd;
            margin-bottom: 20px;
            transition: all 0.3s ease;
        }
        .form-control:focus, .form-select:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 0.25rem rgba(198, 40, 40, 0.25);
        }
        footer {
            background-color: var(--secondary-color);
            color: white;
            padding: 80px 0 30px;
        }
        .footer-logo {
            font-size: 2rem;
            font-weight: 800;
            color: var(--primary-color);
            margin-bottom: 20px;
        }
        .footer-logo span {
            color: white;
        }
        .footer-about {
            margin-bottom: 30px;
        }
        .footer-links h5, .footer-contact h5 {
            color: white;
            margin-bottom: 25px;
            font-size: 1.2rem;
            position: relative;
            padding-bottom: 10px;
        }
        .footer-links h5:after, .footer-contact h5:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 40px;
            height: 2px;
            background-color: var(--primary-color);
        }
        .footer-links ul {
            list-style: none;
            padding-left: 0;
        }
        .footer-links li {
            margin-bottom: 12px;
        }
        .footer-links a {
            color: #bbb;
            text-decoration: none;
            transition: all 0.3s ease;
        }
        .footer-links a:hover {
            color: var(--primary-color);
            padding-left: 5px;
        }
        .footer-contact p {
            color: #bbb;
            margin-bottom: 15px;
        }
        .footer-contact i {
            color: var(--primary-color);
            margin-right: 10px;
            width: 20px;
        }
        .copyright {
            border-top: 1px solid #444;
            padding-top: 30px;
            margin-top: 50px;
            text-align: center;
            color: #aaa;
            font-size: 0.9rem;
        }
        .friendlink {
            padding: 60px 0;
            background-color: #f9f9f9;
        }
        .flink {
            display: inline-block;
            padding: 10px 25px;
            margin: 5px 10px;
            background-color: white;
            border-radius: 5px;
            color: var(--secondary-color);
            text-decoration: none;
            transition: all 0.3s ease;
            border: 1px solid #eee;
            font-weight: 500;
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        .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: 1.2rem;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s ease;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: #b71c1c;
            transform: translateY(-5px);
        }
        @media (max-width: 768px) {
            .hero h1 {
                font-size: 2.5rem;
            }
            .hero p {
                font-size: 1rem;
            }
            .section-title {
                font-size: 1.8rem;
            }
            .contact-form {
                padding: 25px;
            }
            .navbar-collapse {
                background-color: white;
                padding: 20px;
                border-radius: 10px;
                box-shadow: 0 10px 30px rgba(0,0,0,0.1);
                margin-top: 15px;
            }
        }
        .section-padding {
            padding: 100px 0;
        }
        .section-padding-sm {
            padding: 60px 0;
        }
        .bg-light {
            background-color: #f9f9f9 !important;
        }