Recently I've started using the calc(...) method within CSS. I quickly learned that code such as:
In addition, whitespace is required on both sides of the + and -
operators. (The * and / operaters can be used without whitespace
calc(100% - 1)
- character is one of the allowed characters in CSS idents. Judging by the resolution given here, it seems they wanted to prevent syntactic ambiguities that could arise from using
- without whitespace, especially with keyword values such as
min-content (although AFAIK keyword values aren't yet allowed within
calc() — correct me if I'm wrong).
Not everyone agrees with this resolution, though.