:root {
            --primary-color: #1a365d;
            --secondary-color: #c53030;
            --accent-color: #ed8936;
            --light-color: #f7fafc;
            --dark-color: #2d3748;
            --transition: all 0.3s ease;
        }
        body {
            font-family: "Microsoft YaHei", "Segoe UI", 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);
        }
        .navbar-brand {
            font-size: 1.8rem;
            font-weight: bold;
            color: var(--primary-color) !important;
        }
        .navbar-nav .nav-link {
            font-weight: 500;
            color: var(--dark-color) !important;
            transition: var(--transition);
        }
        .navbar-nav .nav-link:hover,
        .navbar-nav .nav-link.active {
            color: var(--secondary-color) !important;
        }
        .hero-section {
            background: linear-gradient(rgba(26, 54, 93, 0.85), rgba(26, 54, 93, 0.9)), url('https://images.unsplash.com/photo-1523381210434-271e8be1f52b?ixlib=rb-1.2.1&auto=format&fit=crop&w=1920&q=80') no-repeat center center/cover;
            color: white;
            padding: 150px 0;
        }
        .hero-section h1 {
            color: white;
            font-size: 3.5rem;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 50px;
        }
        .section-title::after {
            content: '';
            position: absolute;
            left: 50%;
            bottom: 0;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--secondary-color);
        }
        .card {
            border: none;
            box-shadow: 0 10px 30px rgba(0,0,0,0.08);
            transition: var(--transition);
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 40px rgba(0,0,0,0.15);
        }
        .card-img-top {
            height: 220px;
            object-fit: cover;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 12px 30px;
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            transform: scale(1.05);
        }
        .bg-light-custom {
            background-color: var(--light-color);
        }
        .flink {
            display: inline-block;
            padding: 12px 24px;
            margin: 10px;
            background: white;
            border-radius: 8px;
            color: var(--primary-color);
            text-decoration: none;
            font-weight: 600;
            box-shadow: 0 4px 12px rgba(0,0,0,0.08);
            transition: var(--transition);
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-5px);
        }
        .friendlink {
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            padding: 80px 0;
        }
        footer {
            background-color: var(--primary-color);
            color: white;
        }
        footer a {
            color: #cbd5e0;
            text-decoration: none;
            transition: var(--transition);
        }
        footer a:hover {
            color: white;
            text-decoration: underline;
        }
        .social-icons a {
            display: inline-block;
            width: 40px;
            height: 40px;
            background: rgba(255,255,255,0.1);
            border-radius: 50%;
            text-align: center;
            line-height: 40px;
            margin-right: 10px;
            transition: var(--transition);
        }
        .social-icons a:hover {
            background: var(--secondary-color);
            transform: rotate(360deg);
        }
        .product-img {
            height: 300px;
            object-fit: cover;
            border-radius: 10px;
            transition: var(--transition);
        }
        .product-img:hover {
            transform: scale(1.03);
        }
        .stats-number {
            font-size: 3rem;
            font-weight: 800;
            color: var(--secondary-color);
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
            .section-title {
                font-size: 1.8rem;
            }
            .stats-number {
                font-size: 2.5rem;
            }
        }