Style trouble

Hi,
I have some problem between this wonderful plugin and my theme (a premium version bought days ago).
I cannot understand where I can modify the style because the actual is not so smart…

https://www.cafmestre.it/inviare-ticky/

I tried to change the theme with the standard one but the results is the same…
Could you please help me?
Thanks for your support.

The page I need help with: [log in to see the link]