JSFiddle - React, Tailwind, and code Playground

HTML

<html>
    <head></head>
    <body>
<div id="center_content" class="border" style="float:left;width:70%;height:400px;position:relative">
<div class="boxes" id="box1" style="position:absolute;left:0px;top:0px;opacity:1"></div>

<div class="boxes" id="box2" style="position:absolute;right:0px;top:0px;opacity:1"></div>
</div>
</body>
</html>

CSS

.border{
    border:2px solid;
}
.boxes{
    border:2px solid;
    height:400px;
    width:100px;
    z-index:10;
}