Supporting multiple themes for your website is a difficult problem to solve. If you did it even a couple of years ago, you would agree with that. Quite often solution was to have wholly duplicated stylesheets. But that is messy. Maintaining an enormous stylesheet for each theme is not good. What if you have more than two. It is easy to miss some change and not notice it. It is also a performance issue. Unnecessary data to load. Thankfully, with CSS variables, this feature became much more comfortable to implement. And here is how.
