JSFiddle - React, Tailwind, and code Playground

HTML

<div id="maparea">
    <table>
        <tr>
            <td>
                left column
            </td>
            <td>
                <table>
                    <tr>
                        <td>
                            <div id="hello">hello</div>
                        </td>
                    </tr>
                </table>
            </td>
        </tr>
    </table>
</div>

CSS

html, body, #maparea, table, #hello { height: 100%; }
table { width: 100%; }
#hello { background: blue; color: white; }
td { border: thin solid black; }