JSFiddle - React, Tailwind, and code Playground

HTML

<div class="progress-bar">
    <div>
    </div>
</div>

CSS

.progress-bar {
    width: 300px;
    height: 35px;
    
    border: 1px solid #2c3e50;
}

.progress-bar div {
    width: 0%;
    height: 100%;
    
    background-color: #34495e;
}

JavaScript

$(function() {
    var nMax = 99;
    var nWidth = 0;
    var nSpeed = 100;
    
    var $progressBar = $('.progress-bar div');
    
    var oInterval = window.setInterval(function() {
        nWidth += (nMax - nWidth) / 100;
        
        $progressBar.stop().animate({
            width: nWidth + '%'
        }, nSpeed);
        
        if(Math.round(nWidth) === nMax) window.clearInterval(oInterval);
    }, nSpeed);
});