var didScroll;$(window).scroll(function(){1<$(this).scrollTop()?$("header").addClass("sticky"):$("header").removeClass("sticky")});var lastScrollTop=0,delta=5,navbarHeight=$("header").outerHeight();function hasScrolled(){var l=$(this).scrollTop();Math.abs(lastScrollTop-l)<=delta||(lastScrollTop<l&&navbarHeight<l?$("header").removeClass("nav-down").addClass("nav-up"):l+$(window).height()<$(document).height()&&$("header").removeClass("nav-up").addClass("nav-down"),lastScrollTop=l)}$(window).scroll(function(l){didScroll=!0}),setInterval(function(){didScroll&&(hasScrolled(),didScroll=!1)},250);