I agree. I really think it's practically impossible to be capable of writing CSS and still have difficulty understanding CSS constants. The whole idea of CSS is

I agree. I really think it's practically impossible to be capable of writing CSS and still have difficulty understanding CSS constants. The whole idea of CSS is that instead of declaring your style inline over and over again, you declare it in one place and then apply it to an entire class of layout element. Every concept that is part of "constant" is fundamental to understanding CSS in the first place.