JSFiddle - React, Tailwind, and code Playground
HTML
<!DOCTYPE>
<html>
<head>
<title>Gmail like loader</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script>
<script>
function callMe(inc)
{
inc = inc || 10
var w = parseInt((parseInt($("#inner").css("width"))/parseInt($("#inner").parent().css("width")))*1000)+ inc;
$("#inner").width(w+"%");
if(w>100)$("#inner").width(0);
}
$(document).ready(function(){
var id = setInterval(callMe,1000);
});
</script>
</head>
<body>
loading...
<div id="outer" style="border:1px solid;width:200px;height:10px;overflow:hidden;">
<div id="inner" style="background-color:#0F67A1;height:100%;width:0%;"/>
</div>
</body>
</html>