:root {
            --primary-blue: #1a5276;
            --secondary-teal: #17a2b8;
            --accent-gold: #ffc107;
            --deep-ocean: #154360;
            --coral-pink: #e74c3c;
        }
        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            line-height: 1.7;
            color: #333;
            background: linear-gradient(135deg, #e6f7ff 0%, #ffffff 100%);
        }
        .logo-brand {
            font-family: 'Georgia', serif;
            font-weight: bold;
            font-size: 1.8rem;
            color: var(--primary-blue);
            text-shadow: 1px 1px 3px rgba(0,0,0,0.1);
        }
        .nav-link {
            font-weight: 500;
            transition: all 0.3s ease;
            border-radius: 5px;
            margin: 0 2px;
        }
        .nav-link:hover {
            background-color: rgba(26, 82, 118, 0.1);
            transform: translateY(-2px);
        }
        .hero-section {
            background: linear-gradient(rgba(21, 67, 96, 0.8), rgba(21, 67, 96, 0.9)), url('https://via.placeholder.com/1200x600') center/cover no-repeat;
            color: white;
            padding: 4rem 0;
            border-radius: 0 0 20px 20px;
            margin-bottom: 2rem;
        }
        h1, h2, h3 {
            color: var(--primary-blue);
            margin-bottom: 1.2rem;
            font-weight: 700;
        }
        h1 {
            font-size: 2.5rem;
            text-shadow: 1px 1px 2px rgba(0,0,0,0.1);
        }
        h2 {
            font-size: 2rem;
            border-left: 5px solid var(--secondary-teal);
            padding-left: 15px;
            margin-top: 2.5rem;
        }
        h3 {
            font-size: 1.5rem;
            color: var(--deep-ocean);
            margin-top: 2rem;
        }
        .content-section {
            background: white;
            border-radius: 15px;
            box-shadow: 0 5px 25px rgba(0,0,0,0.08);
            padding: 2.5rem;
            margin-bottom: 2rem;
        }
        .feature-icon {
            font-size: 2rem;
            color: var(--secondary-teal);
            margin-bottom: 1rem;
        }
        .img-fluid {
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            transition: transform 0.3s ease;
            margin: 1.5rem 0;
        }
        .img-fluid:hover {
            transform: scale(1.02);
        }
        .highlight-box {
            background: linear-gradient(135deg, #e3f2fd 0%, #f3e5f5 100%);
            border-left: 4px solid var(--accent-gold);
            padding: 1.5rem;
            border-radius: 0 10px 10px 0;
            margin: 1.5rem 0;
        }
        .key-feature {
            background: white;
            border-radius: 10px;
            padding: 1.5rem;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            height: 100%;
            transition: transform 0.3s ease;
        }
        .key-feature:hover {
            transform: translateY(-5px);
        }
        footer {
            background: var(--deep-ocean);
            color: white;
            padding: 2rem 0;
            margin-top: 3rem;
        }
        .back-to-top {
            position: fixed;
            bottom: 20px;
            right: 20px;
            background: var(--primary-blue);
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            box-shadow: 0 3px 10px rgba(0,0,0,0.2);
            transition: all 0.3s ease;
            z-index: 1000;
        }
        .back-to-top:hover {
            background: var(--secondary-teal);
            transform: translateY(-3px);
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2rem;
            }
            h2 {
                font-size: 1.7rem;
            }
            .content-section {
                padding: 1.5rem;
            }
            .hero-section {
                padding: 2.5rem 0;
            }
        }
        .fact-box {
            background: #e8f4f8;
            border-radius: 10px;
            padding: 1rem;
            margin: 1rem 0;
            border-left: 4px solid var(--secondary-teal);
        }
        strong {
            color: var(--primary-blue);
        }
        .table-of-contents {
            background: #f8f9fa;
            border-radius: 10px;
            padding: 1.5rem;
            margin-bottom: 2rem;
        }
        .toc-item {
            padding: 0.5rem 0;
            border-bottom: 1px solid #dee2e6;
        }
        .toc-item:last-child {
            border-bottom: none;
        }