Can someone help with some wordpress css problems?

Normally I’d be able to do this myself if it was a normal site… but I’m using a wordpress blog, and it’s not as easy to control.

How do I change the css so there are no borders around some form input fields? And if I do that, will it be the same across the whole site?

Because I don’t want any borders on my donate button/form field, but on my contact form it doesn’t look bad… although there are only borders around the name and email fields, and not the message, so I would want it to be consistent.

Here are the pages I’m talking about:

http://www.ashestobeauty.net/?page_id=44
http://www.ashestobeauty.net/?page_id=93

Thanks for any help!!