I’m trying to set the width of a navigation bar on a WordPress site via CSS. It should be 52.5em on Mac (Safari/Chrome/Firefox). However, that setting causes the menu to break and wrap into two lines on Windows (IE).
Is there a better way to set the width so that it looks good in all browsers (rather than a static width value)? I tried width: 100%, but it did this:

My CSS is:
#navigation {
width: 52.5em;
}
Link: VET PETS
width: 760px; !!!! no auto!!!
use a devel… tools of firefox Ctrl+Shift+I