JSFiddle - React, Tailwind, and code Playground

HTML

<iframe class="if" name="result" sandbox="allow-forms allow-popups allow-scripts allow-same-origin allow-modals" frameborder="0" src="//fiddle.jshell.net/kizu/zfUyN/show/">
</iframe>

CSS

html { height: 100%; }

.if {
  width: 100%;
  height: 100%;
  background: yellow;
  border: 2px dashed red;
}

body {
  width: 100%;
  height: 100%;
}