JSFiddle - React, Tailwind, and code Playground

HTML

<div class="menu">
  menu
</div>
<div class="content">
  <div>
    start<br>text<br>text<br>text<br>text<br>
    text<br>text<br>text<br>text<br>text<br>
    text<br>text<br>text<br>text<br>text<br>
    text<br>text<br>text<br>text<br>text<br>
    text<br>text<br>text<br>text<br>end<br>
  </div>
</div>

CSS

html,body{margin:0;padding:0;height:100%;}
.menu{height:50px;border-bottom:1px solid #bbb;}
.content{position:absolute;top:50px;bottom:0;left:0;right:0;overflow:auto;}