JSFiddle - React, Tailwind, and code Playground

HTML

<header>HEADER</header>
<section id="main">
    <section id="sidebar1">SIDEBAR: STATIC</section>
    <section id="content">CONTENT AREA: AUTO</section>
    <section id="sidebar2">SIDEBAR: FLUID 30%</section>
</section>
<footer>FOOTER</footer>

CSS

*
{
    color: #FFF;
    font-family: Arial;
    text-align: center;
}

html, body
{
    height: 100%;
}

header
{
    background-color: #900;
    height: 100px;
    position: relative;
    z-index: 1000;
}

#main
{
    display: table;
    height: 100%;
    margin: -100px 0;
    width: 100%;
}


#sidebar1
{
    background-color: #333;
    display: table-cell;
    padding: 100px 0;
    width: 150px;
}

#content
{
    background-color: #999;
    display: table-cell;
    padding: 100px 0;
}


#sidebar2
{
    background-color: #333;
    display: table-cell;
    padding: 100px 0;
    width: 30%;
}

footer
{
    background-color: #009;
    height: 100px;
}