I'm developing a system that allows for changing some of the css parameters without accessing the code. To achieve that I have jQuerry objects like sliders and draggers which influence how the site looks user side, eg. $("#MainContent").css("width", "55%");. Now I need a way to append those changes to a .css file on the server.

Let me clarify that this is sort of a CMS system, and only administrator of the system would have this option, not the visitors of user-end site. I realise that .css is one for all users.

Ideal solution would connect to the server every time user makes a change, and replace only one line of css code. But I have no idea how to do it efficiently or if it at all possible.