Parenthesis pair mangled when variables declared within a CSS function

Hello,

I try to transform a css file (material-components-web.css) that contains variables declared in differents ways.
Some of them are not replaced by the plugin. For example :
background-color: color(var(--mdc-theme-text-primary-on-primary, white));
gives :
background-color: color(white;
So it miss a ')' before ';'

I had a look to the code of the plugin and I think that I found a solution. In the file resolve-value.js, I modified the regex variable :
RE_VAR_FUNC = (/var\((--[^,\s]+?)(?:\s*,\s*(.+))?\)/)
to
RE_VAR_FUNC = (/var\((--[^,\s]+?)(?:\s*,\s*([^\)\(]+|(.+)))?\)/);

It seems to work. If it is ok for you, can you implement it in your future versions?
Thx

Start in resolve-value.js and inspect the RE_VAR_FUNC expression. Reproduce the material-components-web.css example with color(var(--mdc-theme-text-primary-on-primary, white)); then verify that transforming it preserves the closing parenthesis before the semicolon. The proposed regular-expression change provides a starting point, and done means the variable is replaced without mangling the function.