Two CSS questions for Simple Market

I am very new so I've been posting away questions that to you are very basic I'm sure. My two questions are ...

1. Do you have any custom CSS that I can use to change the color of the buttons in Simple Market, the size and type and color of fonts in the shopping cart?

2. Is there a Simple Market CSS style sheet that shows me all available options that I could review and learn by example what options are available to modify?