Mobile Version Custom CSS

I’m trying to edit the form on this page:

http://www.amhersthypnosiscenter.com/free-hypnosis-interview/

The form goes off the visible area on mobile. I’d like to make it narrower, or take out the padding, or float left or something so the entry fields are visible.

I’ve set up a custom css to make a few mobile edits (which has worked great so far), but I can not figure out how to write the css to access this div or style… it keeps changing the non-form part of the text as well — as, in, all the text ends up with an orange background, but it’s still not changing the location of the form.

Any help much appreciated!