CSS Cleanup For Internet Explorer

I have a website that I am working on located at [login to view URL] and I am wanting someone to review our current CSS stylesheet and make updates to it so that it will look accurate on Internet Explorer (versions 8, 9, 10, and 11). The web pages look accurate in Safari on a Mac. There are issues with the column layouts, font loading, and other errors. I can provide snapshots if needed. I also would like updates made to the current CSS stylesheet so that it will perform well on smart phone devices. I guess this would mean a media query of @media only screen and (min-device-width : 320px) and (max-device-width : 568px).