JSFiddle - React, Tailwind, and code Playground

HTML

<div class="" id="popupContainer">
<div class="flex-item-popup" id="popup">
    <div class="close"><i class="fa fa-2x fa-times-circle">1</i></div>
    <h2>2</h2>
    <div class='text'>a</div>
    <div class="videos">b</div>
    <div class="flex-container images">c</div>
</div>

CSS

#popupContainer {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    display:none;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    align-content: flex-start;
    align-items: center;
    z-index: 15;
    background-color: red;
}
#popupContainer *{
    border: 1px solid blue;
background-color: white;    
}

JavaScript

$("#popupContainer")
    .css("display", "flex")
    .hide()
    .fadeIn();