JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
  <div class="box a">Header</div>
  <div class="box b">Main</div>
  <div class="box c">Footer</div>
</div>

CSS

body {
  padding: 20px;
  font-family: Helvetica;
  overflow: hidden;
  height: 100vh;
}

.wrapper {
  display: grid;
  grid-template-rows: auto 1fr auto;
  grid-gap: 5px;
  min-height: 100%;
  overflow: hidden;
}

.box {
  background-color: #20262e;
  color: #fff;
  border-radius: 3px;
  padding: 20px;
  font-size: 14px;
  overflow: auto;
}

.b {
  min-height: 700px;
  overflow: auto;
}