Code block change seems to have affected page display?

Hello – I have several code blocks on my site, one of which is to insert the Candid.org logo and link on our Donate page. I was trying to center that block with custom CSS in Enfold>General Styling>Quick CSS, but the code I entered didn’t seem to work, so I deleted it. However, now all my web pages seem as if they are constricting into the center of the display. Can you tell me why, and/or how to correct this?