Add the following CSS code to the Divi theme options area or your child theme style.css file.
sub, sup {
font-size: 75%;
/* Zero out the line-height so that it doesn't
interfere with the positioning that follows */
line-height: 0;
position: relative;
vertical-align: baseline;
}
sup {
/* Move the superscripted text up */
top: -1.25em;
}
sub {
/* Move the subscripted text down, but only
half as far down as the superscript moved up */
bottom: -0.25em;
}