New from EXISTING style?

Is there a way to copy a style, in order to make a 2nd slightly edited copy? I have a style I want to reuse, but one is on a page, and the other is on a sidebar, which makes the widths different, and I want the same style on both. It would be great if I could copy the style in use, and make the one width change, and save it with a new name so i could use it on the sidebar as well. ?? But I don’t see a way to copy a style, or to create a new style FROM AN EXISTING style. That is highly needed feature.

it’s no use to put the page I want help with, because I can’t leave the form up there. I want to duplicate the one on the home page, which has width at 50% (only way to make responsive, right?) …I guess I can put a div tag outside of it, and change the width maybe…

But what I really want is just to copy a style so I can use a modified copy of it.

The page I need help with: [log in to see the link]