Ey, eligeme a mi!

dabblet.css

/**
 * Ey, eligeme a mi! 
 */
body {
	background: #EFEFEF;
}

div.recuadro {
  	background: #fff;
	margin: 0 300px;
	width: 200px;
	padding: 50px;
	text-align: center;
	-webkit-border-radius: 5px;
	-moz-border-radius: 5px;
	border-radius: 5px;
	-webkit-box-shadow: rgba(0,0,0,0.2) 0px 1px 3px;
	-moz-box-shadow: rgba(0,0,0,0.2) 0px 1px 3px;
	box-shadow: rgba(0,0,0,0.2) 0px 1px 3px;  
}
@-webkit-keyframes flash {
    0%, 50%, 100% {opacity: 1;}
    25%, 75% {opacity: 0;}
}

@keyframes flash {
    0%, 50%, 100% {opacity: 1;}
25%, 75% {opacity: 0;}
}

.recuadro {
    -webkit-animation-name: flash;
    animation-name: flash;

    animation-duration: 1s;
    -webkit-animation-duration: 1s;

    -webkit-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
}

dabblet.html

<div class="recuadro">Pasa el cursor por encima</div>

dabblet.js

// alert('Hello world!');

settings.json

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