WHEN I EXPAND HEIGHT ON FORM, IT CHANGES OTHER FORMS ON SITE, CAN I ADD DIV CLASS

Located here https://www.mindfulscience.es/monthly-subscription/

You will see the Submit button is cut off.. if I change the height via CSS, it changes the height on other form locations on the site since it shares the same class..

How would I give this form its own class so I can change the height of the form without impacting the form site wide? Is that possible?

Thanks

EJ