:root {
            --primary-color: #0056b3;
            --secondary-color: #17a2b8;
            --accent-color: #ff6b35;
            --dark-color: #343a40;
            --light-color: #f8f9fa;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
            color: #333;
            line-height: 1.7;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5, h6 {
            font-weight: 700;
            color: var(--dark-color);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .navbar-brand span {
            color: var(--accent-color);
        }
        .hero-section {
            background: linear-gradient(rgba(0, 84, 179, 0.85), rgba(0, 84, 179, 0.9)), url('https://images.unsplash.com/photo-1550745165-9bc0b252726f?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80') center/cover no-repeat;
            color: white;
            padding: 180px 0 120px;
            position: relative;
        }
        .hero-section h1 {
            font-size: 3.2rem;
            color: white;
            margin-bottom: 1.5rem;
            text-shadow: 0 2px 10px rgba(0,0,0,0.2);
        }
        .hero-section p {
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto 2rem;
        }
        .btn-primary {
            background-color: var(--accent-color);
            border-color: var(--accent-color);
            padding: 12px 32px;
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: #e05a2b;
            border-color: #e05a2b;
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        }
        .section-title {
            position: relative;
            margin-bottom: 3.5rem;
            text-align: center;
        }
        .section-title h2 {
            display: inline-block;
            font-size: 2.5rem;
            position: relative;
            padding-bottom: 15px;
        }
        .section-title h2:after {
            content: '';
            position: absolute;
            width: 70px;
            height: 4px;
            background: var(--accent-color);
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
        }
        .section-title p {
            color: #666;
            max-width: 700px;
            margin: 1rem auto 0;
        }
        .feature-box {
            background: white;
            padding: 2.5rem 2rem;
            border-radius: 10px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.05);
            transition: var(--transition);
            height: 100%;
            border-top: 4px solid transparent;
        }
        .feature-box:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 35px rgba(0,0,0,0.1);
            border-top-color: var(--accent-color);
        }
        .feature-icon {
            font-size: 2.8rem;
            color: var(--primary-color);
            margin-bottom: 1.5rem;
            display: inline-block;
        }
        .product-card {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 8px 25px rgba(0,0,0,0.08);
            transition: var(--transition);
            height: 100%;
        }
        .product-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 35px rgba(0,0,0,0.15);
        }
        .product-card img {
            height: 240px;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        .product-card:hover img {
            transform: scale(1.05);
        }
        .product-card .card-body {
            padding: 1.8rem;
        }
        .badge-custom {
            background-color: var(--primary-color);
            color: white;
            padding: 5px 12px;
            border-radius: 20px;
            font-size: 0.85rem;
        }
        .timeline {
            position: relative;
            max-width: 1200px;
            margin: 0 auto;
        }
        .timeline::after {
            content: '';
            position: absolute;
            width: 6px;
            background-color: var(--primary-color);
            top: 0;
            bottom: 0;
            left: 50%;
            margin-left: -3px;
            border-radius: 10px;
        }
        .timeline-item {
            padding: 10px 40px;
            position: relative;
            width: 50%;
            box-sizing: border-box;
        }
        .timeline-item:nth-child(odd) {
            left: 0;
        }
        .timeline-item:nth-child(even) {
            left: 50%;
        }
        .timeline-content {
            padding: 20px 30px;
            background-color: white;
            position: relative;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
        }
        .timeline-item:nth-child(odd) .timeline-content::after {
            content: " ";
            position: absolute;
            right: -15px;
            top: 20px;
            border-top: 15px solid transparent;
            border-right: none;
            border-left: 15px solid white;
            border-bottom: 15px solid transparent;
        }
        .timeline-item:nth-child(even) .timeline-content::after {
            content: " ";
            position: absolute;
            left: -15px;
            top: 20px;
            border-top: 15px solid transparent;
            border-left: none;
            border-right: 15px solid white;
            border-bottom: 15px solid transparent;
        }
        .circle {
            position: absolute;
            width: 25px;
            height: 25px;
            right: -12px;
            background-color: var(--accent-color);
            border: 5px solid var(--primary-color);
            border-radius: 50%;
            z-index: 1;
            top: 20px;
        }
        .timeline-item:nth-child(even) .circle {
            left: -13px;
        }
        .contact-info-box {
            background: linear-gradient(135deg, var(--primary-color), #007bff);
            color: white;
            padding: 2.5rem;
            border-radius: 15px;
            height: 100%;
            box-shadow: 0 10px 30px rgba(0,86,179,0.2);
        }
        .contact-info-box i {
            font-size: 2.5rem;
            margin-bottom: 1.5rem;
            opacity: 0.9;
        }
        .friendlink {
            background-color: #f8f9fa;
            padding: 60px 0;
        }
        .flink {
            display: inline-block;
            background: white;
            padding: 12px 25px;
            margin: 8px;
            border-radius: 8px;
            color: var(--dark-color);
            text-decoration: none;
            font-weight: 500;
            transition: var(--transition);
            border: 1px solid #eaeaea;
        }
        .flink:hover {
            color: var(--primary-color);
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            border-color: var(--primary-color);
        }
        footer {
            background-color: var(--dark-color);
            color: rgba(255,255,255,0.8);
            padding: 60px 0 30px;
        }
        footer h5 {
            color: white;
            margin-bottom: 1.5rem;
            font-size: 1.2rem;
        }
        footer a {
            color: rgba(255,255,255,0.7);
            text-decoration: none;
            transition: color 0.3s;
        }
        footer a:hover {
            color: white;
        }
        .footer-bottom {
            border-top: 1px solid rgba(255,255,255,0.1);
            padding-top: 20px;
            margin-top: 40px;
            font-size: 0.9rem;
        }
        .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;
            font-size: 1.2rem;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            text-decoration: none;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--accent-color);
            color: white;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.2rem;
            }
            .hero-section {
                padding: 130px 0 80px;
            }
            .section-title h2 {
                font-size: 1.8rem;
            }
            .timeline::after {
                left: 31px;
            }
            .timeline-item {
                width: 100%;
                padding-left: 70px;
                padding-right: 25px;
            }
            .timeline-item:nth-child(even) {
                left: 0;
            }
            .circle {
                left: 18px !important;
                right: auto;
            }
            .timeline-item:nth-child(odd) .timeline-content::after,
            .timeline-item:nth-child(even) .timeline-content::after {
                left: -15px;
                right: auto;
                border-left: none;
                border-right: 15px solid white;
            }
        }