It's a pretty odd use for a preprocessor.
Each mixin is only used once (so why bother?) and the calcs are turned into percentages by the compiler (so why bother?)
I have a CSS code that looks like this for a good reason:
left: calc(100% + 2em)
I have a CSS code that looks like this for a good reason:
that I'd like it to be changed to support legacy stock Android browsers.