What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
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.
Yes this is possible. Actually no need to download the full source of the form jotform has a function that allows you to embed your CSS custom for your own styling. Please see this guide https://www.jotform.com/help/117-How-to-Inject-Custom-CSS-Codes.
1. Click on Setup and Embed
2. Click on Preferences
3. Click on Form Styles
4. Add your CSS under "Inject Custom CSS" section