:root {
            --primary-color: #ff6b35;
            --secondary-color: #f7931e;
            --accent-color: #2ec4b6;
            --dark-color: #1a1a2e;
            --light-color: #f8f9fa;
        }
        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            line-height: 1.7;
            color: #333;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            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);
        }
        .hero-section {
            background: linear-gradient(rgba(26,26,46,0.8), rgba(26,26,46,0.9)), url('https://via.placeholder.com/1200x600') center/cover no-repeat;
            color: white;
            padding: 5rem 0;
            border-radius: 0 0 30px 30px;
            margin-bottom: 3rem;
        }
        .content-section {
            background: white;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            padding: 2.5rem;
            margin-bottom: 2rem;
            transition: transform 0.3s ease;
        }
        .content-section:hover {
            transform: translateY(-5px);
        }
        h1, h2, h3 {
            color: var(--dark-color);
            margin-bottom: 1.5rem;
        }
        h1 {
            font-size: 2.8rem;
            font-weight: 800;
            text-align: center;
            margin-bottom: 1rem;
        }
        h2 {
            font-size: 2rem;
            border-left: 5px solid var(--primary-color);
            padding-left: 1rem;
            margin-top: 2.5rem;
        }
        h3 {
            font-size: 1.5rem;
            color: var(--secondary-color);
            margin-top: 2rem;
        }
        .highlight {
            background: linear-gradient(120deg, #ff6b3515 0%, #f7931e15 100%);
            border-left: 4px solid var(--primary-color);
            padding: 1.5rem;
            border-radius: 0 10px 10px 0;
            margin: 1.5rem 0;
        }
        .game-feature {
            background: var(--light-color);
            border-radius: 10px;
            padding: 1.5rem;
            margin: 1rem 0;
            transition: all 0.3s ease;
        }
        .game-feature:hover {
            background: white;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        .feature-icon {
            font-size: 2rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        img {
            max-width: 100%;
            height: auto;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            margin: 1.5rem 0;
        }
        .img-caption {
            text-align: center;
            font-style: italic;
            color: #666;
            margin-top: -0.5rem;
            margin-bottom: 1.5rem;
        }
        .table-of-contents {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border-radius: 15px;
            padding: 2rem;
            margin: 2rem 0;
        }
        .table-of-contents h3 {
            color: white;
            border-left: none;
            padding-left: 0;
        }
        .table-of-contents ul {
            padding-left: 1.5rem;
        }
        .table-of-contents li {
            margin-bottom: 0.7rem;
        }
        .table-of-contents a {
            color: white;
            text-decoration: none;
            transition: all 0.3s ease;
        }
        .table-of-contents a:hover {
            color: var(--accent-color);
            padding-left: 5px;
        }
        .key-term {
            font-weight: bold;
            color: var(--primary-color);
        }
        footer {
            background: var(--dark-color);
            color: white;
            padding: 3rem 0;
            margin-top: 3rem;
        }
        .back-to-top {
            position: fixed;
            bottom: 20px;
            right: 20px;
            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 3px 10px rgba(0,0,0,0.2);
            transition: all 0.3s ease;
            z-index: 1000;
        }
        .back-to-top:hover {
            background: var(--secondary-color);
            transform: translateY(-3px);
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
            h2 {
                font-size: 1.7rem;
            }
            .hero-section {
                padding: 3rem 0;
            }
            .content-section {
                padding: 1.5rem;
            }
        }