JSFiddle - React, Tailwind, and code Playground

HTML

<div class="mainDiv">
<div class="testDiv">

</div>


</div>

CSS

.mainDiv {
    position: relative;
}

.testDiv {
    border: 1px solid;
    height: 700px;
    left: 100px;
    position: fixed;
    top: 100px;
    width: 200px;
}