JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div id="rightBar"></div>
    <div id="leftBar">
        <video id="largeVideo" autoplay="autoplay"></video>
    </div>
</body>

CSS

html {
    height: 100%;
    /* Workaround until http://stackoverflow.com/a/2629446/14731 works */
    font-size: 0;
    overflow: none;
}
body {
    background-color: #000000;
    height: 100%;
    margin: 0;
    padding: 0;
}
#leftBar {
    margin-right: 400px;
    height: 100%;
}
#largeVideo {
    position: relative;
    width: 100%;
    max-height: 100%;
    background-color: red;
}
#rightBar {
    position: fixed;
    width: 400px;
    height: 100%;
    right: 0;
    background-color: blue;
}