Possible fix for values with different unit limitation

[NikarashiHatsu]

Hi, this library has a lot of potential and I will definitely use it in the future. But, upon stumbling this issue below, I got an idea on how to fix this.

I'm definitely not an expert in this library/package field of thing, but it just accross my head for a while. What if we could get the unit of the first argument (for example using the screenshot above, which is 1rem), then convert the second argument (18px) to 1.125rem?

Just in case my explanation is not clear enough, my step-by-step that crossed in mind is:

1. Get the first argument's unit (in this case, it is rem).
2. Convert 1rem to px, which is 16px.
3. Divide the second argument to the first converted argument, which is 18px/16px, which results in 1.125rem.
4. Re-combine the first and the second argument so it could be ~p-[1rem]/[1.125rem]

The another limitation in mind is, it is hard to comply every different units, but I think it is a good first step to resolve the limitation.