CSS实现文字上标、下标

.sup{vertical-align:super; color:red; font-size:9px; font-family:Arial, Helvetica, sans-serif;
margin:10px 0px 0px 0px}

.sub{vertical-align:sub; color:red; font-size:9px; font-family:Arial, Helvetica, sans-serif;
margin:10px 0px 0px 0px}