Centring some element

center-with-table-cell.css

.wrap {
	/* Unimportant styling. */
	background-color: #ffa500;
	width: 400px;
	height: 200px;
	
	/* Solution (part I)*/
	/* This code allows element inside the .wrap to be positioned in the middle. */
	display: table-cell;
	vertical-align: middle;
}
.centre {
	/* Another unimportant styling. */
	width: 200px;
	background-color: #424242;
	color: #fff;
	text-align: center;
	
	/* Solution (part II) */
	/* Now we have a vertical centring. */
	margin: 0 auto;
}

dabblet.html

<div class="wrap">
	<div class="centre">I'm the centre of the universe!</div>
</div>

settings.json

{"view":"split-vertical","seethrough":"","prefixfree":"1","page":"css"}