List of steps to reproduce (step by step, including full links if applicable):

• Try saving the below fragment in a Sanitized CSS page of TemplateStyles

@counter-style thumbs {
  system: cyclic;
  symbols: "\1F44D";
  suffix: " ";
}

ul {
  list-style: thumbs;
}

What happens?:
You get an error

• First you get an error by eslint of CodeEditor T217775: CodeEditor does not recognized the @counter-style rule

Then you get an error from saving by TemplateStyles/css-sanitizer

• Unrecognized or unsupported rule at line 1 character 1.
• Invalid or unsupported value for property list-style at line 8 character 15.

What should have happened instead?:
You should be able to save the CSS. This is part of Level 3 of

• https://developer.mozilla.org/en-US/docs/Web/CSS/@counter-style
• Part of Counter styles Level 3. https://www.w3.org/TR/css-counter-styles-3/
• Browser support October 18th 70%: https://caniuse.com/?search=%40counter-style