:root {
            --primary-blue: #1e40af;
            --sapphire: #0ea5e9;
            --royal-purple: #7e22ce;
            --gold-accent: #f59e0b;
            --deep-indigo: #3730a3;
        }
        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            line-height: 1.7;
            color: #334155;
            background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            background: linear-gradient(135deg, var(--sapphire), var(--deep-indigo));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            text-shadow: 0 2px 4px rgba(0,0,0,0.1);
        }
        .hero-section {
            background: linear-gradient(135deg, var(--deep-indigo) 0%, var(--royal-purple) 100%);
            color: white;
            padding: 4rem 0;
            border-radius: 0 0 2rem 2rem;
            margin-bottom: 3rem;
        }
        .content-section {
            background: white;
            border-radius: 1rem;
            padding: 2.5rem;
            box-shadow: 0 10px 25px rgba(0,0,0,0.05);
            margin-bottom: 2rem;
            border-left: 5px solid var(--sapphire);
        }
        h1, h2, h3 {
            color: var(--deep-indigo);
            font-weight: 700;
            margin-bottom: 1.5rem;
        }
        h1 {
            font-size: 2.5rem;
            text-align: center;
            margin-bottom: 2rem;
        }
        h2 {
            font-size: 2rem;
            border-bottom: 3px solid var(--gold-accent);
            padding-bottom: 0.5rem;
            margin-top: 2.5rem;
        }
        h3 {
            font-size: 1.5rem;
            color: var(--royal-purple);
            margin-top: 2rem;
        }
        .keyword-highlight {
            background: linear-gradient(120deg, #fef3c7 0%, #fef3c7 100%);
            padding: 0.2rem 0.5rem;
            border-radius: 0.375rem;
            font-weight: 600;
            color: var(--deep-indigo);
        }
        .feature-icon {
            font-size: 2rem;
            color: var(--sapphire);
            margin-bottom: 1rem;
        }
        .img-container {
            border-radius: 1rem;
            overflow: hidden;
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
            margin: 2rem 0;
            transition: transform 0.3s ease;
        }
        .img-container:hover {
            transform: translateY(-5px);
        }
        .nav-pills .nav-link.active {
            background: linear-gradient(135deg, var(--sapphire), var(--deep-indigo));
            font-weight: 600;
        }
        .nav-pills .nav-link {
            color: var(--deep-indigo);
            font-weight: 500;
            margin: 0.25rem 0;
            border-radius: 0.5rem;
        }
        .nav-pills .nav-link:hover {
            background-color: #e0f2fe;
        }
        footer {
            background: linear-gradient(135deg, var(--deep-indigo) 0%, #1e1b4b 100%);
            color: white;
            padding: 3rem 0 2rem;
            margin-top: 4rem;
        }
        .emoji-divider {
            text-align: center;
            font-size: 1.5rem;
            margin: 1.5rem 0;
            opacity: 0.7;
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 2.5rem 0;
                border-radius: 0 0 1rem 1rem;
            }
            h1 {
                font-size: 2rem;
            }
            h2 {
                font-size: 1.75rem;
            }
            .content-section {
                padding: 1.5rem;
            }
        }
        .table-of-contents {
            background: #f8fafc;
            border-radius: 1rem;
            padding: 2rem;
            margin-bottom: 2rem;
            border-left: 5px solid var(--gold-accent);
        }
        .toc-list {
            list-style-type: none;
            padding-left: 0;
        }
        .toc-list li {
            margin-bottom: 0.75rem;
            padding-left: 1rem;
            border-left: 3px solid transparent;
            transition: all 0.3s ease;
        }
        .toc-list li:hover {
            border-left-color: var(--sapphire);
            padding-left: 1.5rem;
        }
        .toc-list a {
            text-decoration: none;
            color: var(--deep-indigo);
            font-weight: 500;
        }
        .toc-list a:hover {
            color: var(--sapphire);
        }