JSFiddle - React, Tailwind, and code Playground

by etianqq

HTML

<div class="box">
<div class="center">center</div>
</div>

CSS

.box {
    width: 300px;
    height: 300px;
    border: 1px solid blue;
    position: relative;
}

.center {
    margin: auto;
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    width: 100px;
    height: 100px;
    background-color: green;
}