CF_FixedHeader.js

// Fixed header
    $(window).scroll(function(fixedHeader){ 
        var headerHeight = $('#article-header').height();
        var titleHeight = $('#article-header h1').outerHeight();
        var fixedTop = (headerHeight - titleHeight);

        if ($(this).scrollTop() >= fixedTop){ 
            $('#article-header').addClass('fixedHeader');
            $('#article-header.fixedHeader').css("top", -fixedTop);
        }
        if ($(this).scrollTop() < fixedTop){
            $('#article-header').removeClass('fixedHeader');
            $('#article-header').css('top', '0'); 
        } 
    });