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.
To do this, you can use the source code of the form to embed on your website.
Check the user guide: How-to-get-the-Full-Source-Code-of-your-Form
Once the source code of the form is on your website, you can mix/add your own CSS code to those on form's.
Let us know if there is more we can help you with.