* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
            line-height: 1.6;
            color: #333;
            background-color: #f8f9fa;
        }

        header {
            background: linear-gradient(135deg, #009ee0 0%, #0077b3 100%);
            color: white;
            padding: 2rem 0;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        h1 {
            font-size: 2.5rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
            color: white;
        }

        nav {
            background-color: #ffffff;
            border-bottom: 3px solid #009ee0;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
            position: sticky;
            top: 0;
            z-index: 100;
        }

        nav ul {
            list-style: none;
            display: flex;
            flex-wrap: wrap;
            padding: 0;
            margin: 0;
        }

        nav ul li {
            position: relative;
        }

        nav ul li a {
            display: block;
            padding: 1rem 1.5rem;
            color: #333;
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s ease;
        }

        nav ul li a:hover {
            background-color: #009ee0;
            color: white;
        }

        main {
            background-color: white;
            margin: 2rem auto;
            padding: 3rem 2rem;
            max-width: 1200px;
            box-shadow: 0 0 20px rgba(0, 0, 0, 0.08);
            border-radius: 8px;
        }

        article h2 {
            color: #009ee0;
            font-size: 2rem;
            margin-top: 2rem;
            margin-bottom: 1rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid #e9ecef;
        }

        article h3 {
            color: #0077b3;
            font-size: 1.5rem;
            margin-top: 1.5rem;
            margin-bottom: 0.75rem;
        }

        article h4 {
            color: #333;
            font-size: 1.25rem;
            margin-top: 1.25rem;
            margin-bottom: 0.5rem;
        }

        article p {
            margin-bottom: 1.25rem;
            font-size: 1.05rem;
            line-height: 1.7;
            color: #495057;
        }

        article ul, article ol {
            margin-bottom: 1.25rem;
            padding-left: 2rem;
        }

        article li {
            margin-bottom: 0.5rem;
            color: #495057;
        }

        .transition-section {
            background-color: #f1f9ff;
            border-left: 4px solid #009ee0;
            padding: 2rem;
            margin: 2rem 0;
            border-radius: 4px;
        }

        .transition-section p {
            color: #495057;
            font-size: 1.05rem;
            margin-bottom: 1rem;
        }

        .transition-section p:last-child {
            margin-bottom: 0;
        }

        .links-section {
            background: linear-gradient(to bottom, #ffffff 0%, #f8f9fa 100%);
            padding: 3rem 2rem;
            margin: 2rem -2rem -3rem -2rem;
            border-top: 3px solid #e9ecef;
            border-radius: 0 0 8px 8px;
        }

        .links-section h3 {
            color: #009ee0;
            font-size: 1.75rem;
            margin-bottom: 1.5rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid #009ee0;
        }

        .links-section ul {
            list-style: none;
            padding: 0;
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 0.75rem 2rem;
            margin-bottom: 2rem;
        }

        .links-section ul li {
            margin: 0;
        }

        .links-section ul li a {
            color: #0077b3;
            text-decoration: none;
            font-weight: 500;
            display: inline-block;
            padding: 0.5rem 0;
            transition: all 0.3s ease;
            border-bottom: 2px solid transparent;
        }

        .links-section ul li a:hover {
            color: #009ee0;
            border-bottom-color: #009ee0;
            padding-left: 0.5rem;
        }

        footer {
            background-color: #2c3e50;
            color: #ecf0f1;
            padding: 2rem 0;
            margin-top: 3rem;
            text-align: center;
        }

        footer p {
            margin: 0.5rem 0;
        }

        @media (max-width: 768px) {
            h1 {
                font-size: 2rem;
            }

            nav ul {
                flex-direction: column;
            }

            nav ul li a {
                padding: 0.75rem 1rem;
                border-bottom: 1px solid #e9ecef;
            }

            main {
                margin: 1rem;
                padding: 2rem 1.5rem;
            }

            article h2 {
                font-size: 1.5rem;
            }

            article h3 {
                font-size: 1.25rem;
            }

            .links-section {
                padding: 2rem 1.5rem;
                margin: 2rem -1.5rem -2rem -1.5rem;
            }

            .links-section ul {
                grid-template-columns: 1fr;
                gap: 0.5rem;
            }

            .transition-section {
                padding: 1.5rem;
                margin: 1.5rem 0;
            }
        }

        @media (max-width: 480px) {
            h1 {
                font-size: 1.5rem;
            }

            header {
                padding: 1.5rem 0;
            }

            main {
                padding: 1.5rem 1rem;
            }

            article p {
                font-size: 1rem;
            }
        }