Give Wp Donate “button”

Hey, I was able to change background color for amount boxes but the “DONATE” Button is not changing background color or anything. I was able to change the colors using the code below for the boxes with the amounts in them.

.give-donation-level-btn.

The problem is that this code is not changing the “DONATE” box. I literally just need to change the one box.

The page I need help with: [log in to see the link]