RE:Underscores not valid in CSS identifiers?
Forum Post
Jun 21, 2012
Underscores are an invalid character in CSS1 - see CSS1: in CSS1, selectors (element names, classes and IDs) can contain only the characters A-Z, 0-9, and Unicode characters 161-255, plus dash (-); they cannot start with a dash or a digit; they can also contain escaped char...