Missing closing ')' in comma-separated :not() containing concatenation

[stevenvachon]

// This works
element:not(.classA@{suffix}):not(.classB@{suffix}) {
  color: black;
}

// This works
element:not(.classA, .classB) {
  color: black;
}

// This does not work
element:not(.classA@{suffix}, .classB@{suffix}) {
  color: black;
}

[matthew-dean]

That's correct. CSS selectors, Level 3, only allows a simple selector. https://drafts.csswg.org/selectors-3/#negation

CSS selectors, Level 4 may add something beyond a simple selector, but it's still in draft, and we typically don't add parsing rules for stuff that's still in editor's drafts. Lots of those editor drafts go nowhere. Re-open if/when the standard is in CR (candidate recommendation).

(Or, alternatively, open when it's supported by most major browsers: http://caniuse.com/#feat=css-not-sel-list)

[matthew-dean]

To clarify, one could argue that the middle example should throw an error. But both the second and third examples are not valid uses of :not() anyway.