JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://cdn.ckeditor.com/4.4.6/basic/ckeditor.js"></script>
<div id="outer">
    <textarea class="ckeditor" id="editor1" name="editor1"></textarea>
</div>
<button>test</button>

CSS

div>.ckeditor {
    height:100%;
}

JavaScript

document
    .getElementById("outer")
    .style.height = window.innerHeight+"px";