[css-fonts-4] Accept all math functions in `@font-palette-values`

[cdoublev]

Functions such as calc(), var(), and env() are valid within the braces of a @font-palette-values rule.

https://drafts.csswg.org/css-fonts-4/#at-ruledef-font-palette-values

Obviously, I assume this means they are valid descriptor values, not descriptor names. But what is the reason (if any) to only accept calc() rather than all math functions?

[cdoublev]

Never mind. Functions such as calc() are valid, which means all math functions are valid, I guess.

It seems a bit handwavey because I do not think attr(), mix(), toggle(), random-item(), should be valid. Maybe math functions, var(), env() should be explicitly allowed, as a restricted set.

[svgeesus]

It is a bit wooly, agreed. Better?

[cdoublev]

Satisfied, thanks! 😇

Actually math functions seem to be valid anywhere (sorry to remember it so late) but it does not hurt to allow them explicitly in this context, I guess.