JSFiddle - React, Tailwind, and code Playground

HTML

Just some text
<div id="container">
    <table>
        <tr>
            <td class="first"></td>
            <td class="second"></td>
        </tr>
        <tr>
            <td class="first"></td>
            <td class="second"></td>
        </tr>
        <tr>
            <td class="first"><div class="indicator"><div class="subin"></div></div></td>
            <td class="second"></td>
        </tr>
    </table>
</div>

CSS

#container {position: relative;}
table tr td{border:1px solid black; display: table-cell;}
.first {position: relative; height:50px; width:100px; vertical-align: top;}
.second {width:150px;}

.indicator {
    position: relative;
}
.subin {
    position:absolute;
    top:0px;
    left:0px;
    width:10px; 
    height:50px; 
    background-color:green;
}