How to align and how to close Dublin Teamplate - Modal popup

I am using dubling theme.
I have couple of questions:
1. How to close popup on button close?
2. How to align modal popup in page's center?
Any updates on this?

Also, I am having one strage issue.

If I have more content inside the modal pupup message area, then it hides in the bottom and is not able to scroll the page in the service studio.