Search bar is overlapping main menu bar in some browser and when zooming in

Hi,

Any help would be appreciated. In some different browsers the search icon overlaps the menu bar. Currently I’m using the quick css code:

#menu-item-421, #menu-item-401 {
right: -340px;
}

Which gets the two menu items right justified with the search bar. But, on a couple different browsers (FireFox and Internet Explorer) at normal zoom the search icon overlaps the two menu items. And, on other browsers upon zooming it overlaps too or if it’s minimized.

Is there any way to fix this so the search icon stays in it’s place upon any zoom or any browser or any size screen? I’m desperate for help, and on a time crunch! My website is listed below in the private content section.

Thank you in advance!