Selector starting with numeral transpiles incorrectly

[nekitk]

@custom-selector :--3xl .3xl;

:--3xl {
  font-size: 46px;
}

Expected result:

.3xl {
  font-size: 46px;
}

Actual result:

@custom-selector :--3xl .3xl;

class=css-var>:--3xl {
  font-size: 46px;
}

Codepen

[Semigradsky]

The same happens for extension name which contains only dashes:

@custom-selector :------ .xl; 

:------ {
  font-size: 46px;
}

Actual result:

@custom-selector :------ .xl; 

class=css-var>:------ {
  font-size: 46px;
}

But this extension name is correct by spec (https://drafts.csswg.org/css-extensions/#extension-name)

[romainmenke]

@nekitk @Semigradsky

A fix for this has just been released 🎉

Thank you for reporting the issue