Searchbox is fine in IE and Firefox, but moves down 15px in Safari

WP 3.3.1
ATA 3.7.3
www.envirosim.ca

I moved the searchbox up into the menu bar using some css i found elsewhere in BFA (thank-you!) and it works beautifully in IE and Firefox. However, the searchbox shifts down by about 15 pixels or so in Safari. this is driving me NUTS! please help!

here's the regular searchbox css :

border-bottom: 0;
width: 200px;
margin: -117px -18px 0px 0px;
padding: 0;

i tried using conditional CSS in html inserts as follows :
[if Webkit] div.searchbox {
margin: -132px -18px 0px 0px;
}

but nope.. then again, my css abilities are admittedly pretty basic..