Need help centering footer in main page.

Hi everyone, would someone please help! How do I center my footer in the main page? Now it is on the left side.
The web site is (https://he-knows.info). Here is my (style.css) look like! BTW-I have tried many methods already from this forum, but didn’t do any good. https://i1213.photobucket.com/albums/cc480/thethaiguy/css.jpg