The first commented line is your dabblet’s title

dabblet.css

/**
 * The first commented line is your dabblet’s title
 */
.image1 {
	background: red;
	font-size: 10px;
	height: 1em;
	transition: all 1s;
	width: 1em;
	
	/* Drawing */
	box-shadow: 1em 0 #000,
				0 1em #000;	
}			
.image1:hover {
	font-size: 20px;
}

dabblet.html

Roll over the red square :
<div class="image1"></div>

settings.json

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