JSFiddle - React, Tailwind, and code Playground

HTML

<body>
<div id="header"><p>Header</p></div>
<div id="content"><p>Content</p></div>
<div id="sidebar"><p>Sidebar</p></div>
<div id="footer"><p>Footer</p></div>
</body>

CSS

p{
    font-family:Arial;
    font-size:10pt;
}
#content{
    float:left;
    background-color:brown;
    text-align:center;
}
#sidebar{
    float:right;
    width:250px;
    background-color:red;
    text-align:center;
}
#footer{
    clear:both;
    text-align:center;
    margin:auto;
    background-color:grey;
}
#header{
    text-align:center;
    margin:auto;
    padding:10px;
    background-color:grey;
    height:40px;
}