:root {
            --primary-color: #1a5fb4;
            --secondary-color: #2ec27e;
            --dark-color: #1c1c1e;
            --light-color: #f8f9fa;
            --accent-color: #e5a50a;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            line-height: 1.8;
            color: #333;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            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(--secondary-color);
        }
        .hero-section {
            background: linear-gradient(135deg, var(--primary-color) 0%, #0d4a9c 100%);
            color: white;
            padding: 120px 0 80px;
            position: relative;
            overflow: hidden;
        }
        .hero-section::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: url('data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMTIwMCIgaGVpZ2h0PSI2MDAiIHZpZXdCb3g9IjAgMCAxMjAwIDYwMCIgZmlsbD0ibm9uZSIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj48cGF0aCBkPSJNMCwyMDBMMTIwMCw0MDBMMCw2MDBMMTIwMCwwTDAwLDIwMFoiIGZpbGw9IiMxYTVmYjQiIGZpbGwtb3BhY2l0eT0iMC4xIi8+PC9zdmc+') center/cover;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 40px;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--secondary-color);
        }
        .card {
            border: none;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
            transition: all 0.3s ease;
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .feature-icon {
            width: 70px;
            height: 70px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
            color: white;
            font-size: 1.8rem;
        }
        .pricing-card {
            border: 2px solid transparent;
            transition: all 0.3s ease;
        }
        .pricing-card.popular {
            border-color: var(--accent-color);
            position: relative;
        }
        .popular-badge {
            position: absolute;
            top: -12px;
            right: 20px;
            background: var(--accent-color);
            color: white;
            padding: 5px 15px;
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 600;
        }
        .btn-primary {
            background: linear-gradient(to right, var(--primary-color), #0d4a9c);
            border: none;
            padding: 12px 30px;
            border-radius: 30px;
            font-weight: 600;
            transition: all 0.3s ease;
        }
        .btn-primary:hover {
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(26, 95, 180, 0.3);
        }
        .btn-secondary {
            background: linear-gradient(to right, var(--secondary-color), #1a9e5f);
            border: none;
            padding: 12px 30px;
            border-radius: 30px;
            font-weight: 600;
            transition: all 0.3s ease;
        }
        .footer {
            background: var(--dark-color);
            color: #ddd;
            padding: 70px 0 20px;
        }
        .footer a {
            color: #ddd;
            text-decoration: none;
            transition: color 0.3s ease;
        }
        .footer a:hover {
            color: var(--secondary-color);
        }
        .flink {
            display: inline-block;
            padding: 8px 15px;
            margin: 5px;
            background: rgba(255,255,255,0.1);
            border-radius: 5px;
            transition: all 0.3s ease;
        }
        .flink:hover {
            background: var(--primary-color);
            transform: translateY(-3px);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background: 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: all 0.3s ease;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 80px 0 50px;
            }
            .section-title::after {
                left: 0;
                transform: none;
            }
        }