:root {
            --primary-blue: #1e40af;
            --secondary-teal: #0d9488;
            --accent-orange: #ea580c;
            --light-bg: #f0f9ff;
            --dark-text: #1e293b;
        }
        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            line-height: 1.7;
            color: var(--dark-text);
            background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
        }
        .hero-section {
            background: linear-gradient(rgba(30, 64, 175, 0.85), rgba(13, 148, 136, 0.85)), url('https://via.placeholder.com/1200x600') center/cover;
            color: white;
            padding: 4rem 0;
            margin-bottom: 2rem;
        }
        .game-logo {
            font-family: 'Impact', 'Arial Black', sans-serif;
            font-size: 3.5rem;
            font-weight: 900;
            text-shadow: 3px 3px 0 rgba(0,0,0,0.3);
            color: #ffd700;
            letter-spacing: 2px;
        }
        .nav-custom {
            background: rgba(255,255,255,0.95);
            backdrop-filter: blur(10px);
            box-shadow: 0 4px 20px rgba(0,0,0,0.1);
        }
        .section-card {
            background: white;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.08);
            padding: 2rem;
            margin-bottom: 2rem;
            border: none;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .section-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 40px rgba(0,0,0,0.15);
        }
        .content-img {
            border-radius: 12px;
            box-shadow: 0 8px 25px rgba(0,0,0,0.15);
            margin: 1.5rem 0;
            transition: transform 0.3s ease;
        }
        .content-img:hover {
            transform: scale(1.02);
        }
        h1, h2, h3 {
            color: var(--primary-blue);
            font-weight: 700;
            margin-bottom: 1.5rem;
        }
        h1 {
            font-size: 2.8rem;
            border-bottom: 4px solid var(--accent-orange);
            padding-bottom: 0.5rem;
            display: inline-block;
        }
        h2 {
            font-size: 2.2rem;
            border-left: 5px solid var(--secondary-teal);
            padding-left: 1rem;
            margin-top: 2.5rem;
        }
        h3 {
            font-size: 1.8rem;
            color: var(--secondary-teal);
            margin-top: 2rem;
        }
        .key-term {
            background: linear-gradient(120deg, #fef3c7 0%, #fef3c7 100%);
            padding: 0.2rem 0.5rem;
            border-radius: 4px;
            font-weight: 600;
            color: #92400e;
        }
        .highlight-box {
            background: linear-gradient(135deg, #dbeafe 0%, #e0f2fe 100%);
            border-left: 5px solid var(--primary-blue);
            padding: 1.5rem;
            border-radius: 8px;
            margin: 1.5rem 0;
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--secondary-teal);
            margin-bottom: 1rem;
        }
        .table-of-contents {
            background: linear-gradient(135deg, #fef3c7 0%, #fef7ed 100%);
            border-radius: 12px;
            padding: 2rem;
            margin: 2rem 0;
        }
        .toc-item {
            padding: 0.7rem 1rem;
            border-left: 4px solid transparent;
            transition: all 0.3s ease;
            margin-bottom: 0.5rem;
        }
        .toc-item:hover {
            border-left: 4px solid var(--accent-orange);
            background: rgba(255,255,255,0.7);
            transform: translateX(5px);
        }
        footer {
            background: linear-gradient(135deg, var(--primary-blue) 0%, #1e3a8a 100%);
            color: white;
            padding: 3rem 0 2rem;
            margin-top: 4rem;
        }
        @media (max-width: 768px) {
            .game-logo {
                font-size: 2.5rem;
            }
            h1 {
                font-size: 2.2rem;
            }
            h2 {
                font-size: 1.8rem;
            }
            h3 {
                font-size: 1.5rem;
            }
            .section-card {
                padding: 1.5rem;
            }
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            background: var(--accent-orange);
            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: #c2410c;
            color: white;
        }