JSFiddle - React, Tailwind, and code Playground

HTML

<div id="page">
    <div id="pageRow">
    <div id="leftMenu">   
        menu<br/>menu<br/>menu<br/>menu<br/>menu<br/>menu<br/>menu<br/>menu<br/>menu<br/>menu<br/>menu<br/>        
    </div>
    <div id="content">       
        content<br/>content<br/>content<br/>content<br/>content<br/>content<br/>content<br/>content<br/>        
    </div>
    </div>
</div>

CSS

* {   
margin: 0;
padding: 0;
}

html, body {
    height: 100%
}

#page {
    display: table;
    min-height: 100%;
    width: 100%;
}

#pageRow {
    display: table-row;
}

#leftMenu {
    display: table-cell;
    width: 300px;
    background-color: red;
}

#content {
    display: table-cell;
    background-color: blue;
}