:root {
            --primary-blue: #1a5276;
            --secondary-teal: #16a085;
            --accent-gold: #f39c12;
            --deep-ocean: #154360;
            --coral-reef: #e74c3c;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: #333;
            background: linear-gradient(135deg, #e8f4f8 0%, #d1e7f0 100%);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-blue) !important;
            text-shadow: 1px 1px 3px rgba(0,0,0,0.1);
        }
        .nav-link {
            font-weight: 600;
            transition: all 0.3s ease;
        }
        .nav-link:hover {
            color: var(--secondary-teal) !important;
            transform: translateY(-2px);
        }
        h1, h2, h3 {
            color: var(--deep-ocean);
            margin-bottom: 1.5rem;
        }
        h1 {
            border-bottom: 3px solid var(--accent-gold);
            padding-bottom: 0.5rem;
            font-weight: 800;
        }
        h2 {
            border-left: 5px solid var(--secondary-teal);
            padding-left: 1rem;
            margin-top: 2.5rem;
        }
        h3 {
            color: var(--primary-blue);
            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;
            transition: transform 0.3s ease;
        }
        .content-section:hover {
            transform: translateY(-5px);
        }
        .keyword-highlight {
            background-color: rgba(26, 82, 118, 0.1);
            padding: 0.2rem 0.5rem;
            border-radius: 4px;
            font-weight: 700;
            color: var(--primary-blue);
        }
        .feature-icon {
            font-size: 1.5rem;
            color: var(--secondary-teal);
            margin-right: 0.5rem;
        }
        .img-container {
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            margin: 2rem 0;
            transition: transform 0.3s ease;
        }
        .img-container:hover {
            transform: scale(1.02);
        }
        .img-caption {
            background: var(--deep-ocean);
            color: white;
            padding: 0.8rem;
            text-align: center;
            font-style: italic;
        }
        .table-of-contents {
            background: linear-gradient(135deg, var(--primary-blue), var(--deep-ocean));
            color: white;
            border-radius: 10px;
            padding: 2rem;
            margin-bottom: 2rem;
        }
        .toc-link {
            color: white;
            text-decoration: none;
            display: block;
            padding: 0.5rem 0;
            border-bottom: 1px solid rgba(255,255,255,0.2);
            transition: all 0.3s ease;
        }
        .toc-link:hover {
            color: var(--accent-gold);
            padding-left: 1rem;
        }
        .fact-box {
            background: linear-gradient(135deg, #e8f6f3, #d0ece7);
            border-left: 5px solid var(--secondary-teal);
            padding: 1.5rem;
            border-radius: 0 10px 10px 0;
            margin: 1.5rem 0;
        }
        footer {
            background: var(--deep-ocean);
            color: white;
            padding: 2rem 0;
            margin-top: 3rem;
        }
        @media (max-width: 768px) {
            .content-section {
                padding: 1.5rem;
            }
            h1 {
                font-size: 1.8rem;
            }
            h2 {
                font-size: 1.5rem;
            }
        }