Add 'open' class to header when mobile menu open

resources/assets/scripts/routes/common.js

 export default {
     init() {
 
+        let $header = $('header.banner');
+        let $navbar = $('.navbar-collapse');
+
+        $navbar.on('show.bs.collapse', function () {
+            $header.addClass('open');
+        });
+
+        $navbar.on('hide.bs.collapse', function () {
+            $header.removeClass('open');
+        });
 
     },
     finalize() {