body { font-family: 'Arial', sans-serif; line-height: 1.6; color: #333; margin: 0; padding: 0; background-color: #f5f5f5; }
        header { background-color: #1a237e; color: white; padding: 1rem; text-align: center; position: relative; }
        .logo { font-size: 2rem; font-weight: bold; text-shadow: 2px 2px 4px rgba(0,0,0,0.3); }
        nav { display: flex; justify-content: center; gap: 2rem; margin-top: 1rem; }
        nav a { color: white; text-decoration: none; font-weight: bold; }
        .mobile-menu-btn { display: none; position: absolute; top: 1rem; right: 1rem; background: none; border: none; color: white; font-size: 1.5rem; }
        main { max-width: 1200px; margin: 2rem auto; padding: 0 1rem; }
        section { background-color: white; margin-bottom: 2rem; padding: 1.5rem; border-radius: 8px; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
        h1 { color: #1a237e; margin-bottom: 1.5rem; }
        h2 { color: #303f9f; margin-top: 2rem; border-bottom: 2px solid #e3e3e3; padding-bottom: 0.5rem; }
        h3 { color: #3949ab; margin-top: 1.5rem; }
        .btn { display: inline-block; background-color: #ff5722; color: white; padding: 0.8rem 1.5rem; text-decoration: none; border-radius: 4px; font-weight: bold; margin: 0.5rem 0; }
        .download-btn { background-color: #4caf50; }
        .login-btn { background-color: #2196f3; }
        .gallery { display: flex; flex-wrap: wrap; gap: 1rem; margin: 1.5rem 0; }
        .gallery img { width: 100%; max-width: 300px; height: auto; border-radius: 4px; }
        footer { background-color: #333; color: white; text-align: center; padding: 1.5rem; }
        footer a { color: #ffeb3b; text-decoration: none; }
        @media (max-width: 768px) {
            nav { flex-direction: column; align-items: center; display: none; }
            nav.active { display: flex; }
            .mobile-menu-btn { display: block; }
            .gallery { flex-direction: column; align-items: center; }
        }