Editing the Mail Chimp Subscribe Buttons

Hi! Me again! haha

Ok so I removed the Jetpack subscribe button and have added a Mail Chimp one instead. I’ve managed to edit it to a point but can’t seem to get the Subscribe Title/Heading to match the rest of my widget headings.

Any changes I do make then won’t let me save my work, but I think that might just be my site telling me I’m doing it wrong. haha.

Could your perhaps help with this?
fromharperwithlove.com

Thank you in advance! ??