JSFiddle - React, Tailwind, and code Playground

HTML

<button id="open">Open menu</button>
<div class="menu">Tabbable content here</div>

CSS

.menu{
    display: none;
    border: solid 1px navy;
}

JavaScript

$('html').click(function(event) {
  var $menu = $(".menu");
  var $button = $("#open");
  
  if(event.target !== $menu[0] && event.target !== $button[0]){
    // add code here to close your menu...
    $(".menu").hide(); // or similar code
  }
});

$('#open').click(function(event) {
  $(".menu").show();
});