JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
This guide will help you to inject your CSS code: How-to-Inject-Custom-CSS-Codes
We have a Designer tool as well that will help you to add your custom CSS code, to get this till you only need to click on the designer icon, it is placed on the top toolbar while in the form builder:
Here you will be able to paste your custom CSS code:
This link will provide you with some videos about designer as well: -Form-Designer-Tutorial-Let-s-create-fantastic-forms-
Hope this helps.