Actually, it was 9:31 pm for me when I responded:)

If you were copying over your backup file, that would indicate that it was on the server as a CSS file. This can lead to untold headaches, as any style*.css file in the /css/ folder will be autoloaded and applied, so your backup could keep changes to the "real" file from taking effect. If you need to keep a backup on your server, rename it from .css to .css-bak or anything else that will not be processed as code. (".bak" is discouraged by I think PCI for security reasons.)