How to hide header on scroll down & show on scroll up - vanilla Javascript

This video shows how to create a header that hides on scrolling down and shows back again when the user scrolls up. Uses only vanilla javascript, and sample bootstrap template.

Codepen: https://codepen.io/iabhinavr/pen/BaKxvRx ... https://www.youtube.com/watch?v=lOgSy1k80tI