Font size rule doesn't allow functions

[robozdog]

Font size rule and possibly another rules does not support functions.
I'm trying to do following style:
font-size: clamp(100%, 1rem + 2vw, 60px);
But this does not work, style will be empty

[TylerBrinks]

clamp is a css4 function. This library only supports css3 specs currently.

[colindcli]

Why are there so many fatal bugs (infinite loops) and unimplemented rules in the V5 version, the project has not been maintained. . .

[TylerBrinks]

There is no version 5. This library supports CSS3; the function you’re using is not compliant with the CSS 3 spec.

Pull requests are welcome but we have day jobs. The project is maintained but has no outstanding need to adopt forward standards with the current architecture. Future versions will use a different lexer and parser that are DSL appropriate.

As for fatal errors as you put it, to use a library outside of its intended purpose without your own error handling is nonsensical. Again, feel free to contribute with a pull request. Otherwise sideline criticism is useless and generally disregarded.