Getting <sub> and <sup> HTML Tags to Work Properly

If you ever wanted to add subscripts (<sub>) or superscripts (<sup>) and it's not working you can just add this custom css code in Theme Settings -> Custom Code

sub, sup {  
  font-size: 75%;
  line-height: 0;  
  position: relative;  
  vertical-align: baseline;
}
sup {  
  top: -0.5em;
}
sub {
  bottom: -0.25em;
}

Cheers!