Aligning email input and submit button

Hello,

I’ve been trying for ages to get the email input box and the submit button to align seamlessly on the same line, without a space in between in the footer of this website:

http://shamuslu.com

I’ve tried using float, but I’m at a loss here. Help would be greatly appreciated!

Cheers,
Stine

https://ww.wp.xz.cn/plugins/mailchimp-for-wp/