JSFiddle - React, Tailwind, and code Playground

by iamanubhavsaini

HTML

<body><div id="a">
    a
<div id="b">
    b
</div>
    a
    </div></body>

CSS

#a{
    background-color:red;
}
#b{
    background-color:yellow;
    margin:auto;
}

JavaScript

//#a inherits body's width
//so set up the width of the margined-div i.e. #b

alert($('body').width());
//so you always know width of every element dynamically.