How to adjust padding around the contact form submit button on 7.1?

Site URL: https://guppy-giraffe-2ke7.squarespace.com/contact

How do I adjust the padding on the Contact Form Submit Button only? I've searched the forums and used inspect element to find the css for this specific button but it's not working. I've tried it with and without !important at the end too.

input.button.sqs-system-button.sqs-editable-button {
    padding-top: 12px;
    padding-bottom: 16px;
    padding-left: 12px;
    padding-right: 16px;
}

I've also tried this variation with no luck.

input.button.sqs-system-button.sqs-editable-button {
    padding: 12px;
}

Website page: https://guppy-giraffe-2ke7.squarespace.com/contact

Password: CBCConstruction

Thank you!!! 

Hi.

You mean padding around button text

or spacing around button?