uxe cssRules instead of rules

lib/single-file/single-file-core.js

@@ -293,7 +293,7 @@ const SingleFileCore = (() => {
 			doc.querySelectorAll("style").forEach(style => {
 				const cssRules = [];
 				if (style.sheet) {
-					processRules(style.sheet.rules, cssRules);
+					processRules(style.sheet.cssRules, cssRules);
 					style.innerText = cssRules.join("");
 				}
 			});