This code:

 const mobileNavShow = document.querySelector('.mobile-nav-show');

only looks through the index.html of my project, while my navbar is in navbar.html and is out of the scope of querySelector. I used w3’s w3-include-html to link the two. If I copy the contents of navbar.html into the body of index.html, my navbar works as intended. I am unsure of the technical terms of the problem I am facing.

I tried to create a navbar in a separate HTML file, but js “document.querySelector(‘X’)” is unable to find elements in the other HTML file.