JSFiddle - React, Tailwind, and code Playground

HTML

<nav>Nav Stuff</nav>

CSS

nav {
  background: #333;
  color: #fff;
  visibility: hidden;
  opacity: 0;
  transition: all .5s ease;
}

nav.show {
  opacity: 1;
  visibility: visible;
}

JavaScript

var timer;

$(window).on('mousemove', function () {
  $('nav').addClass('show');
  try {
    clearTimeout(timer);
  } catch (e) {}
  timer = setTimeout(function () {
    $('nav').removeClass('show');
  }, 1000);
});