Urgent customized html code for sign up box

Dear team,

I just did a big launch and this is what my clients are seeing, it does not look professional.

I am trying to figure out how to make this sign up box smaller as it does not look good on mobile view?

Here is the link so that you can see how it gets cut off on the mobile screen: www.chrishoward.com

Please kindly advise how to make the box smaller in the design settings or if any addition HTML coding needs to be added?

Warm regards,
Evette & Chris

Can someone please help us out with this? This is causing big problems with our clients especially after a big radio launch :frowning: