JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr><td id="borked">abc</td><td>def</td></tr>
</table>

CSS

#borked {
    background: yellow;
    position: relative;
    height: 100%;
}
#borked~* {
    height: 100px;
}
#borked::before {
    content: "";
    position: absolute;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 0, 0, 0.3);
}

JavaScript

"use strict";
var borked = document.getElementById("borked");
var td = document.createElement("td");
td.textContent = "(1st cell seems to be " + borked.clientHeight + "px tall)";
borked.parentElement.appendChild(td);