Vertical centering with Flexbox + margin fallback

dabblet.css

/**
 * Vertical centering with Flexbox + margin fallback
 * Lea Verou & David Storey
 */

html, body { height: 100%; }

body {
	width: 100%; /* needed for FF */
	margin: 0;
}

div {	
	/* Make it pretty */
	background: slategray;
	text-align: center;
	border-radius: .3em;
	color: #405060;
	text-shadow: 0 2px 1px hsla(0,0%,100%,.2);
	line-height: 15px;
	font-size: 10px;
	padding: 10px

}

dabblet.html

<div><h1>
	Some text that looks funky maybe
</h1></div>

settings.json

{"view":"split","fontsize":"100","seethrough":"","prefixfree":"1","page":"css"}