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

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(to bottom, #f5f5f5 0%, #ffffff 100px);
            color: #333;
            line-height: 1.6;
            min-height: 100vh;
        }

        header {
            background: #ffffff;
            border-bottom: 3px solid #e0e0e0;
            box-shadow: 0 2px 10px rgba(0,0,0,0.05);
            position: sticky;
            top: 0;
            z-index: 1000;
        }

        .header-banner {
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px;
            text-align: center;
        }

        .header-banner h1 {
            font-size: 2rem;
            color: #2c3e50;
            font-weight: 300;
            letter-spacing: 2px;
            text-transform: uppercase;
        }

        nav {
            background: #2c3e50;
            border-top: 1px solid #34495e;
        }

        nav ul {
            list-style: none;
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0;
        }

        nav ul li {
            margin: 0;
        }

        nav ul li a {
            display: block;
            padding: 15px 25px;
            color: #ecf0f1;
            text-decoration: none;
            font-size: 0.95rem;
            transition: all 0.3s ease;
            border-bottom: 3px solid transparent;
        }

        nav ul li a:hover {
            background: #34495e;
            border-bottom-color: #3498db;
        }

        main {
            max-width: 1200px;
            margin: 0 auto;
            padding: 40px 20px;
        }

        h1 {
            font-size: 2.5rem;
            color: #2c3e50;
            margin-bottom: 30px;
            font-weight: 300;
            letter-spacing: 1px;
            text-align: center;
            padding-bottom: 20px;
            border-bottom: 2px solid #e0e0e0;
        }

        article {
            background: #ffffff;
            padding: 40px;
            margin-bottom: 40px;
            border-radius: 8px;
            box-shadow: 0 2px 15px rgba(0,0,0,0.08);
            border-left: 4px solid #3498db;
        }

        article h2 {
            font-size: 1.8rem;
            color: #2c3e50;
            margin: 30px 0 15px 0;
            font-weight: 400;
        }

        article h3 {
            font-size: 1.4rem;
            color: #34495e;
            margin: 25px 0 12px 0;
            font-weight: 400;
        }

        article h4 {
            font-size: 1.2rem;
            color: #34495e;
            margin: 20px 0 10px 0;
            font-weight: 400;
        }

        article p {
            margin-bottom: 20px;
            color: #555;
            font-size: 1.05rem;
            line-height: 1.8;
        }

        article ul, article ol {
            margin: 20px 0 20px 30px;
            color: #555;
        }

        article li {
            margin-bottom: 10px;
            line-height: 1.7;
        }

        .transition-section {
            background: #f8f9fa;
            padding: 35px 40px;
            margin-bottom: 40px;
            border-radius: 8px;
            border: 1px solid #e0e0e0;
        }

        .transition-section p {
            color: #555;
            font-size: 1.05rem;
            line-height: 1.8;
            margin-bottom: 15px;
        }

        .links-section {
            background: #ffffff;
            padding: 40px;
            border-radius: 8px;
            box-shadow: 0 2px 15px rgba(0,0,0,0.08);
            border-left: 4px solid #3498db;
        }

        .links-section h2 {
            font-size: 1.8rem;
            color: #2c3e50;
            margin-bottom: 15px;
            font-weight: 400;
        }

        .links-section h3 {
            font-size: 1.4rem;
            color: #34495e;
            margin: 30px 0 15px 0;
            font-weight: 400;
            padding-bottom: 10px;
            border-bottom: 2px solid #e0e0e0;
        }

        .links-section ul {
            list-style: none;
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 15px 30px;
            margin: 20px 0 30px 0;
        }

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

        .links-section ul li a {
            color: #3498db;
            text-decoration: none;
            font-size: 1rem;
            line-height: 1.6;
            display: block;
            padding: 8px 0;
            transition: all 0.2s ease;
            border-left: 3px solid transparent;
            padding-left: 12px;
        }

        .links-section ul li a:hover {
            color: #2980b9;
            border-left-color: #3498db;
            padding-left: 18px;
        }

        footer {
            background: #2c3e50;
            color: #ecf0f1;
            text-align: center;
            padding: 30px 20px;
            margin-top: 60px;
            border-top: 3px solid #34495e;
        }

        footer p {
            font-size: 0.9rem;
            color: #bdc3c7;
        }

        @media (max-width: 768px) {
            .header-banner h1 {
                font-size: 1.5rem;
                letter-spacing: 1px;
            }

            nav ul {
                flex-direction: column;
            }

            nav ul li a {
                padding: 12px 20px;
                border-bottom: 1px solid #34495e;
            }

            h1 {
                font-size: 1.8rem;
            }

            article {
                padding: 25px 20px;
            }

            article h2 {
                font-size: 1.5rem;
            }

            article h3 {
                font-size: 1.2rem;
            }

            .transition-section {
                padding: 25px 20px;
            }

            .links-section {
                padding: 25px 20px;
            }

            .links-section ul {
                grid-template-columns: 1fr;
                gap: 10px;
            }

            .links-section h2 {
                font-size: 1.5rem;
            }

            .links-section h3 {
                font-size: 1.2rem;
            }
        }

        @media (max-width: 480px) {
            main {
                padding: 20px 15px;
            }

            article {
                padding: 20px 15px;
            }

            .transition-section {
                padding: 20px 15px;
            }

            .links-section {
                padding: 20px 15px;
            }
        }