Allowed characters for CSS identifiers
The charset doesn’t matter. The allowed characters matters more. Check the CSS specification. Here’s a cite of relevance: In CSS, identifiers (including element names, classes, and IDs in selectors) can contain only the characters [a-zA-Z0-9] and ISO 10646 characters U+00A0 and higher, plus the hyphen (-) and the underscore (_); they cannot start with a … Read more