Move the "close" action to a button in a dialog

Would it be possible to take the “close” action and move it to a button on an engagement?

For example, the “x” button on the top/bottom-right is really hard to notice, especially at full screen width:

I don’t want any of my users to be confused and not be able to close the dialog box. I’d rather create a “Dismiss” button do the same thing as the “close-x.”

In the above example, I put the url as “#” on the dismiss button and it will reload the page, which at least completes the engagement, but isn’t very elegant. Any css tips to pull this off?