JSFiddle - React, Tailwind, and code Playground

HTML

<div class="viewport">
    <div class="column">
    </div>
    <div class="column">
                  <br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>
    </div>
    <div class="column">
    </div>
    <div class="column">
    </div>
    <div style="clear:both"></div>
</div>

CSS

.viewport {
    background:#ccc;
    width:610px;
    border:1px #000 solid;
}
.column {
    width:200px;
    height:400px;
    overflow:auto;
    float:left;
    border:1px #f00 solid;
}