Stylesheet switcher --> Buttons for PREV & NEXT

Stylesheet switcher --> Buttons for PREV & NEXT


Hello everybody!

I have a simple jQuery Style Switcher, which can apply new stylesheet from additional CSS file .
It's working with standard buttons -->  each button applies different style.
But I just want to add two buttons more to this navigation: previous & next (with loop).
I have tried to make it by myself but without success..

Here is working demo in Plunker: LINK

Function
  1.     $('.list a').click(function() {

            var rel = $(this).attr('rel');   
                   
            $('.content').fadeOut(500, function(){
                $('.content').hide().fadeIn(500); 
                $('head').append('<link rel="stylesheet" href="' + rel + '" type="text/css" />');
            });
           
        });

HTML
  1. <div class="content"></div>

    <div class="list">
        <a href="#" rel="style1.css">Style 1</a>
        <a href="#" rel="style2.css">Style 2</a>
        <a href="#" rel="style3.css">Style 3</a>
    </div>

Any help?