Screenshot please? If you're making CSS/HTML requests, you should include one so it's easier to understand what you want. Remember that what you're seeing isn't necessarily what people on other browsers are seeing it.
The subject and message textboxes' widths are set to 90%, and there's a similar case where the PM textbox is given a 95% width. They'll actually overflow their containers if set to 100%, which might just be why they aren't 100% in the first place, but that can be fixed by also giving them the property "box-sizing: border-box;".