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.
I would suggest opening the jotform that you want to do this on in your Form Designer.
Once you are in you will be able to change the width, height, colors and do all sorts of amazing things by just clicking on the fields and then changing their styles on the right.
I suggest taking a look here for the best experience: Video Course - Form Designer Basics
Do let us know if you have any further questions or if you need any assistance.