Embedding a MailChimp signup form into Upfront

I have been trying to embed a MailChimp signup form into this website using upfront; however, when I do so it expands the whole page rather than being centered under the logo and "coming soon" text. How do I stop it from stretching across the entire page?

Also, is it possible for me to use the embed code that MailChimp provides. If so how. Because I keep using the code draggable item and embedding it there, and nothing is happening.