JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
    <div id="header">
        header
    </div>
    <div id="main">
        <div id="content">
            cont entcont entcont entcont entcont entcont entcont entcont entcont entcont entcont ent
            cont entcont entcont entcont entcont entcont entcont entcont entcont entcont entcont ent
            cont entcont entcont entcont entcont entcont entcont entcont entcont entcont entcont ent
            cont entcont entcont entcont entcont entcont entcont entcont entcont entcont entcont ent
            cont entcont entcont entcont entcont entcont entcont entcont entcont entcont entcont ent
            cont entcont entcont entcont entcont entcont entcont entcont entcont entcont entcont ent
            cont entcont entcont entcont entcont entcont entcont entcont entcont entcont entcont ent
            cont entcont entcont entcont entcont entcont entcont entcont entcont entcont entcont ent
        </div>
        <div id="sidebar">
            side barside barside barside barside barside barside barside barside barside barside bar
            side barside barside barside barside barside barside barside barside barside barside bar
            side barside barside barside barside barside barside barside barside barside barside bar
            side barside barside barside barside barside barside barside barside barside barside bar
            side barside barside barside barside barside barside barside barside barside barside bar
            side barside barside barside barside barside barside barside barside barside barside bar
            side barside barside barside barside barside barside barside barside barside barside bar
            side barside barside barside barside barside barside barside barside barside barside bar
            side barside barside barside barside barside barside barside barside barside barside bar
            side barside barside barside barside barside barside barside barside barside barside bar
        </div>
   ...

CSS

#wrapper{
    margin:0 auto;
    width:600px;
}
#header{
    background:#f00;
    height:100px;
    margin:0 0 10px;
}
#main{
    background:#f0f;
    margin:0 auto 10px 0;
    width:190px;
}
#main:after{
    clear:both;
    content:'';
    display:block;
}
#content{
    background:#0ff;
    float:right;
    margin:0 -410px 0 0;
    position:relative;
    width:400px;
    z-index:10;
}
#sidebar{position:relative;}
#sidebar:after{
    background:#0ff;
    content:'';
    height:100%;
    left:200px;
    position:absolute;
    top:0;
    z-index:5;
    width:400px;
}
#footer{
    background:#f00;
    height:100px;
}