Doing jQuery in the back-end to take effect in the front-end

Hi,
I build a theme and include the Redux-framework in it.
In the “theme option” tab, I put some button and I want, by clicking this button to change some CSS property in the front-end.
Everything works great but using the “.css” jQuery function on that button works only in the back-end.
How can I do that connection between the front-end and back-end?

Thanks in advance.