:root {
            --primary-color: #FF6B35;
            --secondary-color: #004E89;
            --accent-color: #FFD166;
            --text-dark: #2D3142;
            --text-light: #FFFFFF;
            --bg-light: #F8F9FA;
        }
        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            line-height: 1.7;
            color: var(--text-dark);
            background-color: var(--bg-light);
        }
        .logo-brand {
            font-family: 'Arial Black', Gadget, sans-serif;
            font-size: 2.2rem;
            font-weight: 900;
            color: var(--primary-color);
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
            letter-spacing: -1px;
        }
        .logo-brand span {
            color: var(--secondary-color);
        }
        .navbar {
            background: linear-gradient(135deg, var(--secondary-color) 0%, #1A3A5F 100%);
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
            padding: 1rem 0;
        }
        .nav-link {
            color: var(--text-light) !important;
            font-weight: 600;
            margin: 0 0.5rem;
            transition: all 0.3s ease;
            border-radius: 5px;
            padding: 0.5rem 1rem !important;
        }
        .nav-link:hover {
            background-color: rgba(255,255,255,0.15);
            transform: translateY(-2px);
        }
        .hero-section {
            background: linear-gradient(rgba(0,78,137,0.8), rgba(255,107,53,0.8)), url('https://via.placeholder.com/1600x900') center/cover no-repeat;
            color: var(--text-light);
            padding: 5rem 0;
            text-align: center;
            margin-bottom: 3rem;
        }
        .content-section {
            background: white;
            border-radius: 12px;
            box-shadow: 0 8px 30px rgba(0,0,0,0.08);
            padding: 2.5rem;
            margin-bottom: 2rem;
        }
        h1 {
            color: var(--secondary-color);
            font-weight: 800;
            margin-bottom: 1.5rem;
            font-size: 2.8rem;
            text-shadow: 1px 1px 3px rgba(0,0,0,0.1);
        }
        h2 {
            color: var(--primary-color);
            font-weight: 700;
            margin: 2.5rem 0 1.5rem 0;
            padding-bottom: 0.5rem;
            border-bottom: 3px solid var(--accent-color);
        }
        h3 {
            color: var(--secondary-color);
            font-weight: 600;
            margin: 2rem 0 1rem 0;
        }
        .highlight-box {
            background: linear-gradient(135deg, var(--accent-color) 0%, #FFE8A3 100%);
            border-left: 5px solid var(--primary-color);
            padding: 1.5rem;
            border-radius: 8px;
            margin: 1.5rem 0;
            box-shadow: 0 4px 12px rgba(0,0,0,0.05);
        }
        .feature-icon {
            font-size: 2rem;
            color: var(--primary-color);
            margin-right: 1rem;
            vertical-align: middle;
        }
        .game-image {
            border-radius: 12px;
            box-shadow: 0 8px 20px rgba(0,0,0,0.15);
            margin: 1.5rem 0;
            transition: transform 0.3s ease;
            width: 100%;
            height: auto;
        }
        .game-image:hover {
            transform: scale(1.02);
        }
        .key-point {
            background-color: #E8F4FF;
            border-radius: 8px;
            padding: 1rem;
            margin: 1rem 0;
            border-left: 4px solid var(--secondary-color);
        }
        footer {
            background: linear-gradient(135deg, var(--secondary-color) 0%, #1A3A5F 100%);
            color: var(--text-light);
            padding: 3rem 0 2rem 0;
            margin-top: 4rem;
        }
        .footer-heading {
            color: var(--accent-color);
            font-weight: 700;
            margin-bottom: 1.5rem;
        }
        .social-icon {
            font-size: 1.5rem;
            color: var(--text-light);
            margin-right: 1rem;
            transition: all 0.3s ease;
        }
        .social-icon:hover {
            color: var(--accent-color);
            transform: translateY(-3px);
        }
        .copyright {
            border-top: 1px solid rgba(255,255,255,0.2);
            padding-top: 1.5rem;
            margin-top: 2rem;
            text-align: center;
            font-size: 0.9rem;
            opacity: 0.8;
        }
        .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 4px 12px rgba(0,0,0,0.15);
            transition: all 0.3s ease;
            z-index: 1000;
            text-decoration: none;
        }
        .back-to-top:hover {
            background: var(--secondary-color);
            transform: translateY(-3px);
            color: white;
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
            .hero-section {
                padding: 3rem 0;
            }
            .content-section {
                padding: 1.5rem;
            }
            .logo-brand {
                font-size: 1.8rem;
            }
        }
        .table-of-contents {
            background: #F0F7FF;
            border-radius: 10px;
            padding: 1.5rem;
            margin: 2rem 0;
            border-left: 5px solid var(--secondary-color);
        }
        .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: "▶";
            color: var(--primary-color);
            position: absolute;
            left: 0;
        }
        .toc-list a {
            color: var(--secondary-color);
            text-decoration: none;
            font-weight: 600;
            transition: all 0.2s ease;
        }
        .toc-list a:hover {
            color: var(--primary-color);
            text-decoration: underline;
        }