Superscript rendering in moodle 2.0

The superscript is not aligned properly. I overrode the default settings with

sup

{font-size: .83em;line-height: 0.5em;vertical-align: baseline;position: relative;top: -0.4em;}

sub

{font-size: .83em;line-height:0.5em;vertical-align: baseline;position: relative;top: 0.4em;}

in the general.php of the theme. The difference is clearly seen in the figures. sup1.gif is rendering in moodle.org forum and sup.gif is after adding sup directive.