bramus

const extractLayersFromCssRules = (cssRules) => {
    if (!cssRules || !cssRules.length) return [];
	return [...cssRules].filter((cssRule) => {
			return (cssRule instanceof CSSStyleRule) || (cssRule instanceof CSSLayerBlockRule);
		})
		.flatMap((cssRule) => {
			if (cssRule instanceof CSSLayerBlockRule) {
				return [cssRule.name];
			} else {
                return extractLayersFromCssRules(cssRule.cssRules);