JSFiddle - React, Tailwind, and code Playground

HTML

<div class="stubborn"></div>

<button onclick="show()">show</button>
    <button onclick="hide()">hide</button>

CSS

body { background-color: #000; }
div.stubborn { display: none !important; background-color: red; width: 100px; height: 100px; }
div.stubborn.fade-ready { display: block !important; opacity: 0; }

JavaScript

function show() {
    $('.stubborn').addClass('fade-ready').animate({opacity: 1});
}

function hide() {
    $('.stubborn').fadeOut(function() {
        $(this).removeClass('fade-ready');
    });
}