Centering submit button with image

I have a submit button that is an image I uploaded.   It will not center on the form and it has a white ring around the back side. 

How do I center it and remove the white ring?

https://form.jotform.com/92263485568166

Please inject the following custom css code in your form and that will solve your problem:

button#input_310 {

    border: none !important;

    width: 100% !important;

}

#cid_310 .form-buttons-wrapper {

    text-align: center !important;

}

The following guide should help you how to inject custom css css code in form: https://www.jotform.com/help/117-How-to-Inject-Custom-CSS-Codes 

Hope this helps.

Do get back to us if you have any questions.