How to manage post "author" visibility?

Hello! Near month ago I deleted "author" and date info posts by making "entry-meta" display:none. But now I cannot return "author" to make visible again. Any tries to use ".author" class in css failed. Date is returned to visible successfully. But "author" class not. Please help me! Also I suggest you to add a feature which makes post author an/or date visible/hidden by one click.