*/ $('body').append('Top'); // browser window scroll (in pixels) after which the "back to top" link is shown, default 300 var offset = 300, //browser window scroll (in pixels) after which the "back to top" link opacity is reduced, default 1200 offset_opacity = 5000, //duration of the top scrolling animation (in ms), default 700 scroll_top_duration = 500, //grab the "back to top" link $back_to_top = $('.cd-top'); //hide or show the "back to top" link $(window).scroll(function(){ ( $(this).scrollTop() > offset ) ? $back_to_top.addClass('cd-is-visible') : $back_to_top.removeClass('cd-is-visible cd-fade-out'); if( ($(this).scrollTop() > offset_opacity) && 0) { $back_to_top.addClass('cd-fade-out'); } }); //smooth scroll to top $back_to_top.on('click', function(event){ event.preventDefault(); $('body,html').animate({ scrollTop: 0 , }, scroll_top_duration ); }); });