body { font-family: 'Arial', sans-serif; line-height: 1.6; color: #333; max-width: 1200px; margin: 0 auto; padding: 20px; }
        h1 { color: #FF6B35; text-align: center; }
        h2 { color: #4ECDC4; border-bottom: 2px solid #FF6B35; padding-bottom: 5px; }
        h3 { color: #FF8C42; }
        .download-btn { background: #4CAF50; color: white; padding: 10px 20px; text-align: center; margin: 15px 0; display: inline-block; }
        .login-btn { background: #2196F3; color: white; padding: 10px 20px; text-align: center; margin: 15px 0; display: inline-block; }
        .mobile-nav { display: none; background: #333; color: white; padding: 10px; text-align: center; }
        .desktop-nav { display: block; }
        @media (max-width: 768px) {
            .desktop-nav { display: none; }
            .mobile-nav { display: block; }
        }
        img { max-width: 100%; height: auto; margin: 15px 0; }
        footer { margin-top: 30px; padding-top: 20px; border-top: 1px solid #eee; }