How to optimize JavaScript code with CSS

In the ongoing debate over whether to use JavaScript or CSS in frontend development, the choice often depends on the specific requirements of the project. While JavaScript is favored for its robust libraries that facilitate advanced UI features, it also presents challenges in terms of performance, accessibility, and code complexity. Conversely, CSS, though less feature-rich, aligns better with browsers' native rendering processes, thereby enhancing performance and simplifying code. The discussion highlights scenarios where CSS can outperform JavaScript, particularly in text styling, transitions, animations, and layout, due to its lower processing needs and simpler syntax. The article also delves into how web content rendering impacts performance, explaining that the critical rendering path of browsers is more efficiently navigated using CSS, which is less parser-blocking than JavaScript. It underscores the use of CSS for optimizing page loading speeds, improving SEO, and offering a better user experience, suggesting that developers can leverage CSS's built-in capabilities for tasks like text styling and animations to improve overall app performance. Additionally, tools like Datadog Real User Monitoring (RUM) are recommended for identifying performance bottlenecks and areas where CSS can replace JavaScript to enhance user experience.