chmod for updating css

I built my blog on my local computer and today uploaded it to its permanent server.

I got the necessary redirect to the on-line version.It looks fine, but when I tried to change the css I got a message that the permissions had to be changed in order to save the changes.

I used my ftp program and changed the permissions to 776 for the active theme, formandsubstance, and all its subfolders. It still would not allow me to save changes. I then changed the permissions for the entire wp-content folder and it still gave the same message.

I really don’t want to make the permissions any higher! I can’t really believe they need to be that high.

Can anyone tell me what I’m doing wrong?

Thanks so much!
Diane