ECMAScript 6 alternatives to collapse and responsible Bootstrap menus? : <p>I'm trying to create some responsible hamburger menus in Bootstrap 4 without jQuery, relying only on ECMAScript 6 and it's features. I wasn't able to find alternatives to Bootstrap's collapse.js and animation.js, so i decided to tackle this myself.</p>

<p>What is the preferred way of manipulating the DOM and animating the changes in ES6? </p>
