2) wanted to see if I could add the property: color; to .Popup .arrowWidget in xenforo_popup.css and messed things up when I copied a section of code into EXTRA.CSS
3) I've tried reverting templates with no improvement
By copying HTML code into EXTRA.CSS by mistake, it seems that I've messed up a couple of templates. It looks like the Master Style gets changed along with the Default Style (I was only working with the default style). Is there any way I can restore things? How does one go about diagnosing this?