JSFiddle - React, Tailwind, and code Playground

HTML

<div id="nav"></div>
<button id="button">Toggle</button>

CSS

body {
  margin: 0;
}
div {
  position: fixed;
  left: -100%;
  top: 0;
  bottom: 0;
  width: 100%;
  background: #f00;
  transition: left .2s;
}
.open {
  left: 0;
}
button {
  position: relative;
  z-index: 1;
}
@media (min-width: 768px) {
  div {
    position: static;
    height: 50px;
  }
}

JavaScript

button.addEventListener('click', () => {
	nav.classList.toggle('open')
})