JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">      
    <div class="cell foo">
        <div class="rel">
            a
            <div class="absolute">x</div>
        </div>
    </div>
</div>

CSS

.parent {
    height: 150px;
    width: 450px;
    display: table;
    margin-top: 400px;
    background: #bbb;
}

.row {
    display: table-row;
}

.cell {
    display: table-cell;
    width: 1%;
    background: #c77;
}

.foo, .rel {
    position: relative;
}

.absolute {
    position: absolute;
    top: 0px;
    right: 0px;
    background: #00f;
    color: #fff;
}