:root {
            --primary-color: #ff6b35;
            --secondary-color: #f7931e;
            --accent-color: #2ecc71;
            --text-dark: #2c3e50;
            --text-light: #7f8c8d;
            --bg-light: #f8f9fa;
        }
        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            line-height: 1.7;
            color: var(--text-dark);
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
        }
        .logo-text {
            font-family: 'Georgia', serif;
            font-weight: bold;
            font-size: 2.2rem;
            background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
        }
        .nav-custom {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            box-shadow: 0 4px 20px rgba(0,0,0,0.1);
            transition: all 0.3s ease;
        }
        .nav-link {
            color: var(--text-dark) !important;
            font-weight: 500;
            padding: 0.8rem 1.2rem !important;
            border-radius: 8px;
            transition: all 0.3s ease;
            position: relative;
        }
        .nav-link:hover {
            background: var(--primary-color);
            color: white !important;
            transform: translateY(-2px);
        }
        .nav-link::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            width: 0;
            height: 2px;
            background: var(--primary-color);
            transition: all 0.3s ease;
            transform: translateX(-50%);
        }
        .nav-link:hover::after {
            width: 80%;
        }
        .hero-section {
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            color: white;
            padding: 4rem 0;
            border-radius: 0 0 30px 30px;
            margin-bottom: 3rem;
            position: relative;
            overflow: hidden;
        }
        .hero-section::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 100" fill="%23ffffff" opacity="0.1"><polygon points="1000,100 1000,0 0,100"/>');
            background-size: cover;
        }
        h1 {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            text-shadow: 2px 2px 8px rgba(0,0,0,0.2);
        }
        h2 {
            color: var(--primary-color);
            border-left: 5px solid var(--accent-color);
            padding-left: 1rem;
            margin: 3rem 0 1.5rem 0;
            font-weight: 700;
        }
        h3 {
            color: var(--secondary-color);
            margin: 2rem 0 1rem 0;
            font-weight: 600;
        }
        .content-section {
            background: white;
            border-radius: 20px;
            padding: 3rem;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            margin-bottom: 2rem;
        }
        .highlight-box {
            background: linear-gradient(135deg, #e3f2fd, #f3e5f5);
            border-left: 4px solid var(--accent-color);
            padding: 1.5rem;
            border-radius: 0 12px 12px 0;
            margin: 2rem 0;
        }
        .key-point {
            background: var(--bg-light);
            padding: 1.5rem;
            border-radius: 12px;
            margin: 1.5rem 0;
            border: 1px solid #e9ecef;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .key-point:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }
        .img-container {
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 8px 25px rgba(0,0,0,0.15);
            margin: 2rem 0;
            transition: transform 0.3s ease;
        }
        .img-container:hover {
            transform: scale(1.02);
        }
        .fact-badge {
            display: inline-block;
            background: var(--accent-color);
            color: white;
            padding: 0.5rem 1rem;
            border-radius: 50px;
            font-size: 0.9rem;
            font-weight: 600;
            margin: 0.5rem;
        }
        .cultural-note {
            background: #fff3cd;
            border: 1px solid #ffeaa7;
            border-radius: 10px;
            padding: 1.5rem;
            margin: 2rem 0;
        }
        footer {
            background: var(--text-dark);
            color: white;
            padding: 3rem 0 2rem;
            margin-top: 4rem;
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            background: var(--primary-color);
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            box-shadow: 0 4px 15px rgba(0,0,0,0.2);
            transition: all 0.3s ease;
            z-index: 1000;
        }
        .back-to-top:hover {
            transform: translateY(-5px);
            background: var(--secondary-color);
            color: white;
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.5rem;
            }
            .content-section {
                padding: 2rem 1.5rem;
            }
            .logo-text {
                font-size: 1.8rem;
            }
        }
        .table-of-contents {
            background: var(--bg-light);
            border-radius: 15px;
            padding: 2rem;
            margin: 2rem 0;
        }
        .toc-list {
            list-style-type: none;
            padding-left: 0;
        }
        .toc-list li {
            margin-bottom: 0.8rem;
            padding-left: 1.5rem;
            position: relative;
        }
        .toc-list li::before {
            content: '▸';
            position: absolute;
            left: 0;
            color: var(--primary-color);
            font-weight: bold;
        }
        .toc-list a {
            color: var(--text-dark);
            text-decoration: none;
            transition: color 0.3s ease;
        }
        .toc-list a:hover {
            color: var(--primary-color);
        }