JSFiddle - React, Tailwind, and code Playground

HTML

<div class='container'>
    <div class='content'>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
        askldjfaslkdjflasdjflkasjdflkjasdlfjaslkdf
      </div>
      <div>
       ...

SCSS

html, body {
  height: 100%;
  width: 100%;
  margin: 0;
  padding: 0;
}

body {
  padding: 10px;
}

* {
  box-sizing: border-box;  
}

.container {
  display: flex;
  flex-direction: column;
  height: 100%;
  border: 1px solid black;
}

.content {
  flex: 1;
  overflow-y: scroll;
  
  div {
    padding: 10px;
    display: block;
    width: 100%;
  }
}

.footer {
  display: flex;
  flex: 0 1 auto;
  min-height: 40px;
}