JSFiddle - React, Tailwind, and code Playground

HTML

This is some content
<div id="blocker">
   <div>Loading...</div>
</div>

CSS

#blocker
{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: .5;
    background-color: #000;
    z-index: 1000;
    overflow: auto;
}
    #blocker div
    {
        position: absolute;
        top: 50%;
        left: 50%;
        width: 5em;
        height: 2em;
        margin: -1em 0 0 -2.5em;
        color: #fff;
        font-weight: bold;
    }

JavaScript

setTimeout(function(){
    $("#blocker").hide();
}, 2000);