:root {
            --primary-color: #e74c3c;
            --secondary-color: #f39c12;
            --accent-color: #c0392b;
            --dark-bg: #2c3e50;
            --light-text: #ecf0f1;
            --gradient-bg: linear-gradient(135deg, #e74c3c 0%, #c0392b 100%);
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: #333;
            background-color: #f8f9fa;
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            background: var(--gradient-bg);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            text-transform: uppercase;
            letter-spacing: 1px;
        }
        .nav-link {
            font-weight: 600;
            transition: all 0.3s ease;
            position: relative;
        }
        .nav-link:hover {
            color: var(--primary-color) !important;
        }
        .nav-link::after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            bottom: 0;
            left: 0;
            background-color: var(--primary-color);
            transition: width 0.3s ease;
        }
        .nav-link:hover::after {
            width: 100%;
        }
        .hero-section {
            background: var(--gradient-bg);
            color: white;
            padding: 4rem 0;
            margin-bottom: 3rem;
            border-radius: 0 0 20px 20px;
        }
        h1, h2, h3 {
            font-weight: 700;
            margin-bottom: 1.5rem;
        }
        h1 {
            font-size: 2.8rem;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
        }
        h2 {
            color: var(--accent-color);
            border-left: 5px solid var(--secondary-color);
            padding-left: 15px;
            margin-top: 2.5rem;
        }
        h3 {
            color: var(--dark-bg);
            margin-top: 2rem;
        }
        .content-section {
            background: white;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            padding: 2.5rem;
            margin-bottom: 2rem;
        }
        .highlight-box {
            background: linear-gradient(135deg, #fff9e6 0%, #ffeaa7 100%);
            border-left: 4px solid var(--secondary-color);
            padding: 1.5rem;
            margin: 1.5rem 0;
            border-radius: 0 8px 8px 0;
        }
        .game-feature {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 1.5rem;
            margin-bottom: 1.5rem;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .game-feature:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        img {
            max-width: 100%;
            height: auto;
            border-radius: 8px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            transition: transform 0.3s ease;
            margin: 1.5rem 0;
        }
        img:hover {
            transform: scale(1.02);
        }
        .key-term {
            font-weight: 700;
            color: var(--accent-color);
        }
        .strategy-tip {
            background: #e8f4fd;
            border-radius: 8px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border-left: 4px solid #3498db;
        }
        footer {
            background: var(--dark-bg);
            color: var(--light-text);
            padding: 3rem 0 1.5rem;
            margin-top: 3rem;
        }
        .copyright {
            border-top: 1px solid rgba(255,255,255,0.1);
            padding-top: 1.5rem;
            margin-top: 2rem;
            text-align: center;
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
            .content-section {
                padding: 1.5rem;
            }
            .hero-section {
                padding: 2.5rem 0;
            }
        }
        .toc {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 1.5rem;
            margin-bottom: 2rem;
        }
        .toc ul {
            list-style-type: none;
            padding-left: 0;
        }
        .toc li {
            margin-bottom: 0.5rem;
        }
        .toc a {
            color: var(--dark-bg);
            text-decoration: none;
            transition: color 0.3s ease;
        }
        .toc a:hover {
            color: var(--primary-color);
        }