Connect "Submit" Button beside Form Field

Site URL: http://www.palmettehome.com

Hi!

I'm trying to customize my form field and button within my newsletter block and having a difficult time achieving what I need. I'd like to have my form field and button to connect and sit side by side. Please see attached example of what I would like for it to look like.

Also, How can I customize the size of the form field and button and make sure it formats well for mobile?

Thanks!