Various vertical font alignments in a string on OS X

Question

Various vertical font alignments in a string on OS X

I have a problem with fonts because they don’t appear the same on Windows and OS X. On Windows, the characters are aligned vertically in the line, but on OS X the characters are much closer to the top of the line, I highlighted the text in the screenshots so you can see the difference.

I am using the font Gotham. Any ideas? Should I use browser hacks or a font problem?

JSFiddle Link: http://jsfiddle.net/wewo/myh4amud/

body {
	font-family: 'Gotham', Arial, sans-serif;
	background-color: #282828;
	font-size: 14px;
	font-weight: normal;
}

div {
    color: white;
    font-size: 5em;
    padding-top: 15px;
    padding-bottom: 6px;
    line-height: 1em;
}