JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
<div class="dialog">
    <h1>Some thing</h1>
    <p>Some more</p>
</div>
</div>

CSS

.dialog {
    position: relative;
    top: 50%;
    left: 50%;
    -webkit-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
    
    width: 100%;
    max-width: 200px;
    
    background-color: blue;
    border: 1px solid green;
}

.parent {
    height: 400px !important;
    border: 1px solid red;
    width: 300px;
}