JSFiddle - React, Tailwind, and code Playground

HTML

<div id='progressBar'></div>

CSS

body{
    background:#f6f6f6;    
}

/*Styling of progress bar container*/
#progressBar{
    width:300px;/*It is important to define the width of the progress bar*/
    height:40px;
    padding:0px;
    background:#ccc;
    border:1px solid #aaa;
    -moz-box-shadow: inset 0 0 3px #888;
    -webkit-box-shadow: inset 0 0 3px #888;
    box-shadow: inset 0 0 3px #888;
}
/*styling the progress bar*/

#bar{
    background:#499aed;
    height:100%; 
    width:0; /*sets the bar to 0*/   
}

JavaScript

$(document).ready(function() {

    $('#progressBar').append('<div id="bar"></div>');

    // percentage of completion
    var progress = '100%';

    // Animate the #bar div
    $('#bar').animate({
        width: progress
    }, 6000);

});