JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="inner">
        <iframe src="https://player.vimeo.com/video/135335257?autoplay=false" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
    </div>
</div>

CSS

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}
.container {
    background: #eee;
    height: 100%;
    overflow: hidden;
    padding: 0;
    position: relative;
}
.inner {
    left: 50%;
    min-height: 43.75%;
    padding-top: 56.25%;
    position:absolute;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
}
.container iframe {
    bottom: 0;
    height: 100%;
    left: 0;
    position:absolute;
    right: 0;
    top: 0;
    width: 100%;
}