LondonThroughTheLens on "MailChimp - Form Formatting"

Hello,

I've been using MailChimp for a while now - very pleased with it.

I've recently upgraded by theme to Atrium (Pixel Union), which has messed up the formatting of my form! On the previous template I had (Rainier), the formatting was perfect out of the box.

Any ideas on how I can sort the formatting out?
Basically, I want it much closer together so it looks like a form, rather than spread out over the whole page!

Any ideas?

http://www.londonthroughthelens.com/subscribe/

Thanks,
Ben