"...email.html comprises code only (no design)."
That's exactly how it should be: HTML provides content; CSS styles it.
First question tht springs to my mind: are you sure that you need another form? If you do, that's fine, but it's very easy to incorporate more fieldsets and control their display for those who need to use them with a bit of CSS and JS (in such a way that degrades gracefully, of course).
Anyway, can you post a link to contact.html and a brief note of the site structure as it relates to the other files, please? I'd like to take a look at what you're dealing with.