body { font-family: 'Arial', sans-serif; line-height: 1.6; color: #333; max-width: 1200px; margin: 0 auto; padding: 20px; }
        h1 { color: #0066cc; text-align: center; }
        h2 { color: #004d99; margin-top: 30px; }
        h3 { color: #003366; }
        .nav { background: #0066cc; color: white; padding: 15px; position: sticky; top: 0; display: flex; justify-content: space-between; align-items: center; }
        .nav a { color: white; text-decoration: none; margin: 0 10px; }
        .mobile-nav-btn { display: none; background: #004d99; color: white; border: none; padding: 10px; }
        .content-img { max-width: 100%; height: auto; margin: 20px 0; }
        .download-btn, .login-btn { background: #00cc66; color: white; padding: 15px 30px; text-decoration: none; display: inline-block; margin: 20px 0; font-weight: bold; }
        .tags { margin: 30px 0; }
        .tag { background: #e0e0e0; padding: 5px 10px; margin: 5px; display: inline-block; border-radius: 3px; }
        footer { margin-top: 50px; padding: 20px; background: #f0f0f0; text-align: center; }
        @media (max-width: 768px) {
            .nav { flex-direction: column; }
            .mobile-nav-btn { display: block; }
            .nav-links { display: none; }
            .nav-links.active { display: block; }
        }