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.
You can inject CSS codes to change the height and width of the form collapse.
Here's a sample code
Please take note, though, that the width would only be as wide as the form width, so setting it to a number greater than the form width won't really make a difference.
Let us know if you need further assistance. Thanks!