On specific pricing plans, you can add a custom font style and apply it to the text on your form.
Go to Theme → Typography → and select "Add Custom Style +".
You can then alter the Font Size, Typeface, Weight, etc.
To apply the custom font style to your text, highlight the text on the form and click the arrow that shows up at the end of the options to select and apply the custom style.
Gotchas
You can only apply a custom font style to text that can be highlighted in order to customize.