Selectively ignore a global CSS command

Q: Is there a way to undo a global CSS command in specific places?

I’m using the below code in the theme CSS to have a global indent, however in some places the indent is not appropriate, e.g. the signature. I have contact information below the signature and the two lines are not lined up properly.
}
div.post p {
text-indent: 20px;
}

Putting
}
div.post p {
text-indent: 0px;
}
prior to the signature did not work.

See http://www.CoachMitch.com
Thank you