JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outer">Merci de patienter...
    <span id="inner">Cliquer ici</span>
</div>

CSS

#outer{
    display: inline-block;
    position: relative;
    border: 1px solid black;
}
#inner{
    background-color: white;
    display: inline-block;
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    text-align: center;
}

JavaScript

document.getElementById('inner').onclick = function(){
    this.style.display = 'none';
    /* ... long traitement ... */
    setTimeout(function(){
        document.getElementById('inner').style.display = '';
    }, 2500);
};