Duplicate button style to use site wide - how to access

How do I copy and paste elements that I have already styled? Or how do I access so I don't have to restyle the element again? For example, a button.

I am able to duplicate the button, but it won't let me drag it into a different section inside the same container. Can you explain where or how to do this properly? I have a screenshot if you want me to send that along.

Thanks
Kim