Submit button size

Hi there. Great form. Is there a way to increase the size of the submit button? I would like to make it bigger. Also, enter a hexidecimal color if possible. What about field size? I see there are only options to do mini, small, medium, etc. Can you enter a percentage somewhere? Id like it to fit in the space on my homepage perfectly. (see here:https://kazoocreative.biz/safewateralliance/home-3/) Thank you!