How do CSS custom properties affect performance?

How do CSS custom properties affect performance?

CSS custom properties, also known as CSS variables, can impact performance in various ways. They allow for dynamic styling, which can reduce the need for repetitive code and improve maintainability. However, excessive use or complex calculations can lead to performance issues in rendering.

Are there any specific scenarios where they might slow down rendering?

Yes, if you have a large number of custom properties that are frequently updated or if they are used in complex selectors, it can lead to increased reflows and repaints, which may slow down rendering.

What are some best practices for using CSS custom properties?

Some best practices include limiting the number of custom properties, using them for theming rather than layout, and avoiding complex calculations in their values to maintain performance.

Can I use them in media queries?

Absolutely! CSS custom properties can be used in media queries, allowing for responsive design adjustments based on different screen sizes.