:root {
            --primary-color: #1a365d;
            --secondary-color: #2d3748;
            --accent-color: #e53e3e;
            --light-color: #f7fafc;
            --dark-color: #2d3748;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: #333;
            line-height: 1.6;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            color: var(--primary-color);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .nav-link {
            font-weight: 500;
            transition: var(--transition);
            padding: 0.5rem 1rem !important;
        }
        .nav-link:hover {
            color: var(--accent-color) !important;
            transform: translateY(-2px);
        }
        .hero-section {
            background: linear-gradient(135deg, var(--primary-color) 0%, #4a5568 100%);
            color: white;
            padding: 8rem 0;
            position: relative;
            overflow: hidden;
        }
        .hero-section h1 {
            color: white;
            font-size: 3.5rem;
            margin-bottom: 1.5rem;
        }
        .hero-section p {
            font-size: 1.25rem;
            opacity: 0.9;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 3rem;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--accent-color);
        }
        .card {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            transition: var(--transition);
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .card-img-top {
            height: 220px;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        .card:hover .card-img-top {
            transform: scale(1.05);
        }
        .btn-primary {
            background-color: var(--accent-color);
            border-color: var(--accent-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: #c53030;
            border-color: #c53030;
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(229, 62, 62, 0.3);
        }
        .icon-box {
            width: 70px;
            height: 70px;
            background: linear-gradient(45deg, var(--primary-color), var(--accent-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            color: white;
            font-size: 1.8rem;
        }
        .feature-item {
            padding: 2rem;
            border-radius: 12px;
            background: white;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: var(--transition);
            height: 100%;
        }
        .feature-item:hover {
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
            transform: translateY(-5px);
        }
        .contact-info-item {
            padding: 1.5rem;
            border-radius: 12px;
            background: var(--light-color);
            text-align: center;
            transition: var(--transition);
        }
        .contact-info-item:hover {
            background: #e2e8f0;
            transform: translateY(-5px);
        }
        .contact-icon {
            font-size: 2.5rem;
            color: var(--accent-color);
            margin-bottom: 1rem;
        }
        .footer {
            background-color: var(--primary-color);
            color: white;
            padding: 4rem 0 2rem;
        }
        .footer a {
            color: #cbd5e0;
            text-decoration: none;
            transition: var(--transition);
        }
        .footer a:hover {
            color: white;
            text-decoration: underline;
        }
        .flink {
            display: inline-block;
            background: rgba(255,255,255,0.1);
            color: white;
            padding: 0.5rem 1.5rem;
            border-radius: 50px;
            margin: 0.5rem;
            text-decoration: none !important;
            transition: var(--transition);
            border: 1px solid rgba(255,255,255,0.2);
        }
        .flink:hover {
            background: var(--accent-color);
            transform: translateY(-3px);
            color: white;
            border-color: var(--accent-color);
            text-decoration: none;
        }
        .friendlink {
            background-color: rgba(255,255,255,0.05);
            border-radius: 12px;
            padding: 2rem;
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--accent-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            box-shadow: 0 3px 10px rgba(0,0,0,0.2);
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: #c53030;
            transform: translateY(-3px);
        }
        .timeline-item {
            position: relative;
            padding-left: 30px;
            margin-bottom: 2.5rem;
        }
        .timeline-item::before {
            content: '';
            position: absolute;
            left: 0;
            top: 8px;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            background-color: var(--accent-color);
        }
        .timeline-item::after {
            content: '';
            position: absolute;
            left: 5px;
            top: 20px;
            width: 2px;
            height: calc(100% + 20px);
            background-color: #e2e8f0;
        }
        .timeline-item:last-child::after {
            display: none;
        }
        .testimonial-card {
            background: white;
            border-radius: 12px;
            padding: 2rem;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            position: relative;
            margin: 1rem;
        }
        .testimonial-card::before {
            content: '\f10d';
            font-family: 'Font Awesome 6 Free';
            font-weight: 900;
            position: absolute;
            top: -15px;
            left: 20px;
            background: var(--accent-color);
            color: white;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .stats-number {
            font-size: 3rem;
            font-weight: 800;
            color: var(--accent-color);
            line-height: 1;
        }
        .stats-label {
            font-size: 1.1rem;
            color: var(--secondary-color);
            font-weight: 600;
        }
        .course-badge {
            position: absolute;
            top: 15px;
            right: 15px;
            background: var(--accent-color);
            color: white;
            padding: 0.25rem 0.75rem;
            border-radius: 50px;
            font-size: 0.8rem;
            font-weight: 600;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
            .hero-section {
                padding: 5rem 0;
            }
            .section-title {
                font-size: 2rem;
            }
            .stats-number {
                font-size: 2.5rem;
            }
        }