Styling submit button

Due to a minor conflict with my theme, when I use a form in the footer widget I have to style it to make it look perfect. I'm trying to style the submit button to have a white background and black letters - whereas my form fields have black background and white letters. I've inserted the code below, but I am doing something wrong because the first string is taking over the submit button specific code. By itself, the submit code works, and the other code works as well, but together the submit specific code is ignored or "overruled" by the first code. Any advice?

#gform_input_4{
background-color:#000000 !important;
border-color:#313131 !important;
}
#gform_submit_button_4 {
background-color:#ffffff !important;
color:#000000 !important;
}

Bottom right footer. Thanks for any help Rob. http://emergerbanquet.com/

No changes, but, I also noticed that I was using #gform_wrapper_4 rather than the #gform_input_4

So my actual code (with your changes above) is as follows (note that I did try it with your code above as well with no changes to submit button). Ultimately what I want to learn to do is to target the type attribute specifically, but I failed in all my efforts to do so. If you can show me an example of how to do that, it'll probably prevent me from asking styling questions in the future because that is the power I would prefer to have over the specific fields...

#gform_wrapper_4 input{
background-color:#000000 !important;
border-color:#313131 !important;
}
#gform_input_4 #gform_submit_button_4 {
background-color:#ffffff !important;
color:#000000 !important;
}

Nailed it! (and the type was mine because I told you #gform_input_4 in my original post).

Just so I understand, does the input[type="variable"] that you used cover all of the GF types possible? I just want to understand so that I can choose to target specific types later.

And, for my further education, let's say I had two email fields and I wanted to target a specific one in CSS to change border or background, how do I target a specific instance of a specific type?

Thank you Rob. My apologies for one more question, but that is how I how I presumed to do field-specific targeting. I just am not sure where to look when editing a form to know a field's ID# (or, is it just logical? The first field is field 1, second is field 2, etc.)?