diff --git a/app.js b/app.js
index d5591aea..ae631c8e 100644
--- a/app.js
+++ b/app.js
@@ -1,3 +1,5 @@
+(function(document){
+
 const hamburger = document.querySelector('.header .nav-bar .nav-list .hamburger');
 const mobile_menu = document.querySelector('.header .nav-bar .nav-list ul');
 const menu_item = document.querySelectorAll('.header .nav-bar .nav-list ul li a');
@@ -23,3 +25,5 @@ menu_item.forEach((item) => {
 		mobile_menu.classList.toggle('active');
 	});
 });
+	
+})(document);