:root {
            --primary-color: #6f42c1;
            --secondary-color: #20c997;
            --accent-color: #fd7e14;
            --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, #0f0c29 0%, #302b63 50%, #24243e 100%);
            min-height: 100vh;
        }
        .main-container {
            background-color: white;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.3);
            overflow: hidden;
            margin-top: 20px;
            margin-bottom: 20px;
        }
        .logo-text {
            font-family: 'Arial Black', Gadget, sans-serif;
            font-size: 2.2rem;
            background: linear-gradient(45deg, #6f42c1, #20c997);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            font-weight: 900;
            text-transform: uppercase;
            letter-spacing: 2px;
        }
        .nav-custom {
            background: linear-gradient(90deg, #1a1a2e 0%, #16213e 100%);
            padding: 15px 0;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }
        .nav-link {
            color: #fff !important;
            font-weight: 600;
            margin: 0 10px;
            transition: all 0.3s ease;
            border-radius: 5px;
            padding: 8px 15px !important;
        }
        .nav-link:hover {
            background-color: rgba(255,255,255,0.1);
            transform: translateY(-2px);
        }
        h1, h2, h3 {
            color: var(--dark-color);
            margin-bottom: 1.2rem;
            font-weight: 700;
        }
        h1 {
            font-size: 2.8rem;
            border-left: 5px solid var(--primary-color);
            padding-left: 15px;
            margin-top: 2rem;
        }
        h2 {
            font-size: 2rem;
            border-bottom: 2px solid var(--secondary-color);
            padding-bottom: 10px;
            margin-top: 2.5rem;
        }
        h3 {
            font-size: 1.5rem;
            color: var(--primary-color);
            margin-top: 2rem;
        }
        .content-section {
            padding: 30px;
        }
        .highlight {
            background-color: rgba(111, 66, 193, 0.1);
            border-left: 4px solid var(--primary-color);
            padding: 20px;
            margin: 25px 0;
            border-radius: 0 8px 8px 0;
        }
        .key-term {
            font-weight: 700;
            color: var(--primary-color);
        }
        .game-feature {
            background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
            border-radius: 10px;
            padding: 20px;
            margin: 20px 0;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: transform 0.3s ease;
        }
        .game-feature:hover {
            transform: translateY(-5px);
        }
        .img-container {
            border-radius: 10px;
            overflow: hidden;
            margin: 30px 0;
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        }
        .img-container img {
            width: 100%;
            height: auto;
            transition: transform 0.5s ease;
        }
        .img-container img:hover {
            transform: scale(1.03);
        }
        .footer {
            background-color: var(--dark-color);
            color: white;
            padding: 40px 0 20px;
            margin-top: 50px;
        }
        .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;
            font-size: 1.5rem;
            box-shadow: 0 5px 15px rgba(0,0,0,0.2);
            z-index: 1000;
            transition: all 0.3s ease;
            text-decoration: none;
        }
        .back-to-top:hover {
            background: var(--secondary-color);
            transform: translateY(-5px);
            color: white;
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
            h2 {
                font-size: 1.8rem;
            }
            .logo-text {
                font-size: 1.8rem;
            }
            .content-section {
                padding: 20px;
            }
        }
        .table-of-contents {
            background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
            border-radius: 10px;
            padding: 25px;
            margin: 30px 0;
        }
        .toc-list {
            list-style-type: none;
            padding-left: 0;
        }
        .toc-list li {
            margin-bottom: 10px;
            padding-left: 20px;
            position: relative;
        }
        .toc-list li:before {
            content: "▸";
            position: absolute;
            left: 0;
            color: var(--primary-color);
        }
        .toc-list a {
            color: #333;
            text-decoration: none;
            transition: color 0.3s ease;
        }
        .toc-list a:hover {
            color: var(--primary-color);
        }