JSFiddle - React, Tailwind, and code Playground

by chovy

HTML

<div class="navbar">
navbar
</div>
<section>
  <header>header</header>
  <div class="chat">
  chat window
  </div>
  <footer>
    <textarea>chat enter</textarea>
  </footer>
</section>

CSS

* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
  border: 1px solid gray;
}

.navbar {
  height: 2rem;
}

section {
  height: calc(100vh - 2rem);
}

.chat {
  background-color: green;
  height: 100%;
}