JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5.0/jquery.min.js"></script>
<body>
	<div id="page-wrap">
		<section id="first"></section>
		<section id="second"></section>
		<section id="third">
		  <h1> The specific section </h1>
		  <p>Once you reach this section the bars should start loading</p>
		  
			<div class="meter">
				<span style="width: 33.3%"></span>
			</div>
					
			<div class="meter">
				<span style="width: 80%"></span>
			</div>
				
		</section>
	</div>
</body>

CSS

* { margin: 0; padding: 0; }
body { font: 14px Georgia, serif;height: 2000px; text-align: center; color:#000000}

#page-wrap { width: 960px; margin: auto;}

h1 { font-size: 42px; font-weight: 600; margin: 0 0 30px 0; }

#first{
	background-color: blue;
	height : 750px;
}

#second{
background-color: yellow;
	height : 750px;
}

.meter { 
    height: 20px; 
    position: relative;
    margin: 60px 0 20px 0;
    background: #555;
    -moz-border-radius: 25px;
    -webkit-border-radius: 25px;
    border-radius: 25px;
    padding: 10px;
    -webkit-box-shadow: inset 0 -1px 1px rgba(255,255,255,0.3);
    -moz-box-shadow   : inset 0 -1px 1px rgba(255,255,255,0.3);
    box-shadow        : inset 0 -1px 1px rgba(255,255,255,0.3);
}

.meter > span {
    display: block;
    height: 100%;
    -webkit-border-top-right-radius: 8px;
    -webkit-border-bottom-right-radius: 8px;
    -moz-border-radius-topright: 8px;
    -moz-border-radius-bottomright: 8px;
    border-top-right-radius: 8px;
    border-bottom-right-radius: 8px;
    -webkit-border-top-left-radius: 20px;
    -webkit-border-bottom-left-radius: 20px;
    -moz-border-radius-topleft: 20px;
    -moz-border-radius-bottomleft: 20px;
    border-top-left-radius: 20px;
    border-bottom-left-radius: 20px;
    background-color: yellow;position: relative;
    overflow: hidden;
}

JavaScript

$(function() {
    $(".meter > span").each(function() {
        $(this)
        .data("origWidth", $(this).width())
        .width(0)
        .animate({
            width: $(this).data("origWidth")
        }, 1200);
    });
    
});