JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <div id="leftblock">a</div>
    <div id="contentblock">b</div>
    <div id="rightblock">c<br />c<br />c<br />c<br />c<br />c<br />c<br />c<br />c<br />c<br />c<br />c<br />c<br /></div>
</div>

CSS

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

#container {
    width: 100%;
    display: table;
    table-layout: fixed;
    border: 5px solid #ccc
}
#leftblock {
    display: table-cell;
    padding: 10px;
}
#contentblock {
    width: 400px;
    display: table-cell;
    padding: 10px;
    border: 5px solid #ccc;
    border-top: 0;
    border-bottom: 0;
}
#rightblock {
    display: table-cell;
    padding: 10px;
}