lib/rouge/lexers/css.rb in rouge-3.20.0 vs lib/rouge/lexers/css.rb in rouge-3.21.0

@@ -9,10 +9,12 @@
 
       tag 'css'
       filenames '*.css'
       mimetypes 'text/css'
 
-      identifier = /[a-zA-Z0-9_-]+/
+      # Documentation: https://www.w3.org/TR/CSS21/syndata.html#characters
+
+      identifier = /[\p{L}_-][\p{Word}\p{Cf}-]*/
       number = /-?(?:[0-9]+(\.[0-9]+)?|\.[0-9]+)/
 
       def self.attributes
         @attributes ||= Set.new %w(
           align-content align-items align-self alignment-adjust