diff --git a/_assets/js/main.js b/_assets/js/main.js
index 6f45341..1026b98 100644
--- a/_assets/js/main.js
+++ b/_assets/js/main.js
@@ -1,3 +1,14 @@
 //= require popper
 //= require bootstrap/util
 //= require bootstrap/collapse
+
+"use strict";
+$(function() {
+    let mainMenu = $('#mainmenuNavbar');
+    mainMenu.on('show.bs.collapse', function (e) {
+        $('#submenuNavbar').addClass('invisible');
+    });
+    mainMenu.on('hidden.bs.collapse', function (e) {
+        $('#submenuNavbar').removeClass('invisible');
+    });
+});
\ No newline at end of file
diff --git a/_includes/header.html b/_includes/header.html
index eeb4960..31fe1f5 100644
--- a/_includes/header.html
+++ b/_includes/header.html
@@ -1,5 +1,5 @@
 <header class="site-header">
-    <nav class="navbar navbar-expand-lg navbar-light fixed-top">
+    <nav id="mainmenuNavbar" class="navbar navbar-expand-lg navbar-light fixed-top">
         <div class="container">
             <a class="navbar-brand" href="{{ site.baseurl }}/">
                 <img src="{{ site.data.author.brand_logo }}" width="30" height="30" class="d-inline-block align-top"