JSFiddle - React, Tailwind, and code Playground

HTML

<html>
    <head>
        <title>index</title>
        <link href="ArticleStyleSheet.css" rel="stylesheet" type="text/css" />
    </head>
    <body>
        <div id="wrapper">
            <header>
                Header
            </header>
            <div id="articleContainer">
                Article Container

                <div id="articleContent">
                    The quick brown fox jumped over the lazy dogs back. All good men must come to the aid of the party
                </div>

                <div id="articleSidebar">
                    Article Sidebar
                </div>
            </div>
        </div>
    </body>
</html>

CSS

html, body
{
    padding: 0;
    margin: 0;
}

#wrapper
{
    position: absolute;
    background-color: purple;
    height: 100%;
    width: 100%;
    margin-top: 0px;
}

header
{
    position: absolute;
    width: 100%;
    height: 80px;
    background-color: black;
    color: white;
}


#articleContainer
{
    background-color: blue;
    width: 75%;
    margin-left: auto;
    margin-right: auto;
    height: calc(100% - 80px);
    height: -moz-calc(100% - 80px);
    height: -khtml-calc(100% - 80px);
    height: -webkit-calc(100% - 80px);
    height: -o-calc(100% - 80px);
    height: -ms-calc(100% - 80px);
    margin-top: 80px;
}

#articleContent
{
    width: 70%;
    background-color: yellow;
    float: left;
}

#articleSideBar
{
    position: relative;
    width: 28%;
    background-color: green;
    float: right;
    margin-left: 2px;
    margin-right: 2px;
    display: inline;
    margin-top: 0px;
    float: right;
    height: auto;
}