JSFiddle - React, Tailwind, and code Playground

HTML

<form class="form-inline" role="form">
	<div class="form-group">

		<input type="text" class="form-control" id="getString" placeholder="Enter some string">

	</div>
	<button type="button" class="btn btn-primary" id="nowBtn">Now</button>
</form>

<br/>
<br/>

	All Headings<textarea id="headers" class="form-control" rows="6"></textarea>
</div>

JavaScript

$(document).ready(function () {
    $('#nowBtn').on('click', function () {
        var header = document.createElement('h1'),
            size = size = $(header).css('font-size'),
            $textarea = $('#headers');
        $textarea.val($('#getString').val());
        $textarea.css('font-size', size);
    });
});