JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" id="start">Button</a>
<div id="box"></div>

CSS

a {
   color: #555;
  text-decoration: none;
}

#box { display: none; }

JavaScript

(function() {
    var box = $('#box');
    $(document).on('click', function() {
        if (box.css('display') == 'block') {
            box.css('display', 'none');
        }
    });
    $('#start').on('click', function(e) {
        box.css({
            'text': 'Box',
            'position': 'absolute',
            'top': '50px',
            'left': '0',
            'background': '#EEE',
            'border': '1px solid #555',
            'width': '200px',
            'height': '50px',
            'display': 'block'
        });
        e.stopPropagation();
    });

    box.on('click', function(e) {
        e.stopPropagation();
    });
})();