Are you having troubles containing your form within a containing div?
Check out my clients site that I have been working on. As you can see the form inputs don’t want to conform to the containing div.
*TIP: A more narrow your class selector will help create a better chance to have a single effect with the exact element.
When you have either found a selector or added a selector add the following css.
max-width:100%;
Nothing complicated!
If for some reason this didn’t work for you I would love to hear it in the comments sections.