Changing caption CSS in theme?

I am trying to get my captions working here as there was no CSS for them in the BlueBird Theme. (I spoke with the creator, Randa Clay, and she was very helpful but did not have solution – some I’m coming to you experts!)

I want the caption of an image on this site, https://www.carolyncreative.com, to appear *within* the white padding, extending the blue border down and around the caption below. Ideally, the white would be variable depending on the length of text in the caption, but I’m willing to settle on some caption restraints if I have to do so. I just can’t seem to figure out what I’m doing wrong (or not doing) in the CSS – can you help me please?

Thank you –
Alexa

CSS I have in style.css right now is:

.wp-caption {
margin-right: 20px;
padding: 0px;
}

.wp-caption img {
margin: 5px 10px 10px 5px;
padding: 5px;
border: 1px dotted #69BFDE;
}

.wp-caption p.wp-caption-text {
margin: 0px;
padding: 0px 0px 0px 5px;
font-size: 9px;
font-style: italic;
font-weight: bold;
line-height: 12px;
}