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 do not have IE11 to test functionality you want to achieve but inside of IE8 for me radio buttons are looking like this.
However you can also style radio button inside of Form Designer. When you open Form Designer click on radio button field and than addition options for styling of radio button field and check box field will appear. There you can change color, size. padding, etc.
Hope this will help. Let us know if you need further assistance.