use hidden attribute instead of display style property

Former-commit-id: 237c827c521a330b4e2864bb0da42333e8981b79

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

@@ -789,7 +789,7 @@ this.singlefile.lib.core = this.singlefile.lib.core || (() => {
 			const removedElements = this.doc.querySelectorAll("[" + util.REMOVED_CONTENT_ATTRIBUTE_NAME + "]");
 			this.stats.set("discarded", "hidden elements", removedElements.length);
 			this.stats.set("processed", "hidden elements", removedElements.length);
-			hiddenElements.forEach(element => element.style.display = "none");
+			hiddenElements.forEach(element => element.hidden = true);
 			removedElements.forEach(element => element.remove());
 		}