selector-element-class-no-unknown selector-type-no-unknown unit-no-unknown So, addingat-rule-no-unknownfelt consistent. However, I understand addingat-rule-no-unknowndoes force people who use language extensions (either via a preprocessor like SCSS or vialanguage extension PostCSS plugins), toext...
Does the bug relate to non-standard syntax (e.g. SCSS, Less etc.)? No:https://www.w3.org/TR/css-page-3/#syntax-page-selector What did you expect to happen? No warnings to be flagged. What actually happened (e.g. what warnings or errors did you get)?