JSFiddle - React, Tailwind, and code Playground

HTML

<button id="options">Options</button>
<div id="dropdown-menu" style="display:none;">
<ul>
<li>Option 1</li>
<li>Option 2</li>
<li>Option 3</li>
</ul>
</div>

CSS

#dropdown-menu {
  width: 200px;
  postion: absolute;
  background-color: #eee;
  border: 1px solid #ddd;
}

JavaScript

jQuery( document ).ready( function() {

    jQuery('#options').click( function(){
        jQuery('#dropdown-menu').slideDown();
    });

    jQuery(document).click( function(event) {

        if( !jQuery(event.target).closest('#dropdown-menu').length && !jQuery(event.target).is('#options') ) {

            if(jQuery('#dropdown-menu').is(":visible")) {
                jQuery('#dropdown-menu').hide();
            }
        }
    });
});