(function () {
	var header = document.getElementById("mainHeader");

	if(document.location.pathname != "/"){
		header.classList.toggle("header-background", true);
	}
	
	function changeHeader() {
		var scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
		if(document.location.pathname == "/"){
			header.classList.toggle("header-background", scrollTop >= 50 || document.body.classList.contains("nav-open"));
		}
	}

	var didScroll = false;

	$(window).scroll(function () {
		didScroll = true;
	});

	setInterval(function() {
		if (didScroll) {
			didScroll = false;
			changeHeader();
		}
	}, 100);

	changeHeader();

	document.getElementById("open-nav").addEventListener("click", function (event) {
		event.preventDefault();
		document.body.classList.toggle("nav-open");
		changeHeader();
	});

	$("a[href*=\\#]").on("click", function (event) {
		event.preventDefault();

		$("html, body").animate({
			scrollTop: $(this.hash).offset().top
		}, 500);
	});
})();

(function () {
	var header = document.getElementById("mainHeader");

	if(document.location.pathname != "/"){
		header.classList.toggle("header-background", true);
	}
	
	function changeHeader() {
		var scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
		if(document.location.pathname == "/"){
			header.classList.toggle("header-background", scrollTop >= 50 || document.body.classList.contains("nav-open"));
		}
	}

	var didScroll = false;

	$(window).scroll(function () {
		didScroll = true;
	});

	setInterval(function() {
		if (didScroll) {
			didScroll = false;
			changeHeader();
		}
	}, 100);

	changeHeader();

	document.getElementById("open-nav").addEventListener("click", function (event) {
		event.preventDefault();
		document.body.classList.toggle("nav-open");
		changeHeader();
	});

	$("a[href*=\\#]").on("click", function (event) {
		event.preventDefault();

		$("html, body").animate({
		//	scrollTop: $(this.hash).offset().top
		}, 500);
	});
})();

reconfigure the main.js