JSFiddle - React, Tailwind, and code Playground

HTML

<div>
  <ul>
      <li>1</li>
      <li>2</li>
      <li>3</li>
      <li>4</li>
  </ul>
</div>

CSS

div{
    position:fixed;
    overflow-y: scroll;
    background: grey;
    width: 100%;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    display: flex;
    //align-items: center;
}
li{
    margin: 25em 0;
}