JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="inner"></div>
</div>

CSS

.container {
    border: 1px solid #000;
    height: 500px;
    width: 500px;
}
.inner {
    background: #00f;
    min-width: 200px;
    max-width: 300px;
    height: 300px;
    top: 50%;
    margin: -150px auto 0 auto;
    position: relative;
}