I'm using the theme "Responsive"
In the editor the theme states:
"Please do not edit style.css or any other Theme files or
Templates directly. If you do, your customizations will be lost
as soon as you update Responsive."
Does this mean that if I change the stylesheet in the editor, found under /wp-admin/theme-editor, I'll have to change my customizations every time there's a new version of the theme released?