The area around my button when my typeform is embedded is the wrong colour??? How do I fix

Hi all,

Some help would be much appriciated.

This is my typeform - 

Looks fine.

Yet, when I embed it, there is a strange boarder around the button, which doesn’t exist elsewhere?

Does anyone know what this is and how to fix it?

It appears across multiple browsers.

There doesn’t seem to be an option for this in design of the form, so I don’t know why it exists?

Thanks,

Murray