How do you change the CSS of the Fundraising Panel Widget?

I’d like to change some CSS settings for the Fundraising Panel Widget, specifically with “Fresh” design selected.

As you can see in this screenshot: the text is all smashed together. I’d like “Make this donation…” to be on a new line with some padding between that and the amount text box. As well as “Post this to your profile” to be on a new line, and some padding before the green Back This Project button.

Can you tell me where to edit this CSS and what fields to edit to make this happen?