Ctrl-F / Cmd-F (Mac):
Ctrl-G / Cmd-G (Mac):
Shift-Ctrl-G / Shift-Cmd-G (Mac):
Shift-Ctrl-F / Cmd-Option-F (Mac):
Shift-Ctrl-R / Shift-Cmd-Option-F (Mac):
Specifying the font-size in em allows Internet Explorer, Firefox, Chrome, and Safari to resize the text.
Unfortunately, there is still a problem with IE. When resizing the text, it becomes larger/smaller than it should.