CSS不能与IE和Firefox一起使用，但可以在Chrome中使用

Site jgimprinters.com loads and works fine in Chrome, but not in IE or Firefox. I have verified that IE downloads the style sheet, however it does not apply a lot of the styles. For instance, in IE, the menu button that is supposed to be hidden in full size is showing and all blown out (too big), none of the menu styling is working, background colors of several things is not working. Although the stylesheet is being seen by IE, it is not applying the styles. loads and works fine in C