JSFiddle - React, Tailwind, and code Playground

HTML

<div  id="divOutput">
    <h1>Output</h1> 
    <div id="divButtons">
        <button>One</button>
        <button>Two</button>
    </div>
    <textarea name="tarOutput" id="tarOutput">[Text]</textarea>
</div>

CSS

#divOutput {
    border: 2px solid #000;
    background-color: #f90;
    padding: 10px;
    height: 300px
}

#divButtons {
    border: 2px solid #000;
    background-color: #fb0;
    margin-top: 10px;
    padding: 2px;
}

textarea {
    margin-top: 10px;
    width: 100%;
    height: 100%;
}

JavaScript

/*

How do I make the text area extend to the bottom of #divOutput ?

*/​​