JSFiddle - React, Tailwind, and code Playground

HTML

<a>click</a>

<div class="drop user-menu">user menu asd</div>

CSS

.drop {
    display:none;
    background:blue;
}
a {
    background:black;
    color:white;
}

JavaScript

$(function () { 
    var menu = $('.drop.user-menu');
    menu.on('click',function(e){
        e.stopPropagation();
    });
    $('a').on('click', function (e) {
        menu.fadeIn();
        e.stopPropagation();
    });
    $(document).on('click',function(e){
        if (menu.is(":visible")) {
            menu.fadeOut();
        }
    });
});