demo.css

/* CSS Piano Thanks to http://codepen.io/zastrow/pen/oDBki */
* {
	box-sizing: border-box;
}

body {
	margin: 0;
	background: #222;
}

ul {
	height: 18em;
	width: 34em;
	border-radius: 1em;
	background: #111;
	box-shadow: 0 0 50px rgba(0, 0, 0, 0.5) inset, 0 1px rgba(212, 152, 125, 0.2) inset, 0 5px 15px rgba(0, 0, 0, 0.5);
}

li {
	margin: 0;
	padding: 0;
	list-style: none;
	position: relative;
	float: left;
}

ul .white {
	height: 16em;
	width: 4em;
	z-index: 1;
	border-left: 1px solid #bbb;
	border-bottom: 1px solid #bbb;
	border-radius: 0 0 5px 5px;
	box-shadow: -1px 0 0 rgba(255, 255, 255, 0.8) inset, 0 0 5px #ccc inset, 0 0 3px rgba(0, 0, 0, 0.2);
	background: -webkit-linear-gradient(top, #eee 0%, #fff 100%)
}

ul .white:active {
	border-top: 1px solid #777;
	border-left: 1px solid #999;
	border-bottom: 1px solid #999;
	box-shadow: 2px 0 3px rgba(0, 0, 0, 0.1) inset, -5px 5px 20px rgba(0, 0, 0, 0.2) inset, 0 0 3px rgba(0, 0, 0, 0.2);
	background: linear-gradient(top, #fff 0%, #e9e9e9 100%);
}

.black {
	height: 8em;
	width: 2em;
	margin: 0 0 0 -1em;
	z-index: 2;
	border: 1px solid #000;
	border-radius: 0 0 3px 3px;
	box-shadow: -1px -1px 2px rgba(255, 255, 255, 0.2) inset, 0 -5px 2px 3px rgba(0, 0, 0, 0.6) inset, 0 2px 4px rgba(0, 0, 0, 0.5);
	background: linear-gradient(45deg, #222 0%, #555 100%);
}

.black:active {
	box-shadow: -1px -1px 2px rgba(255, 255, 255, 0.2) inset, 0 -2px 2px 3px rgba(0, 0, 0, 0.6) inset, 0 1px 2px rgba(0, 0, 0, 0.5);
	background: linear-gradient(left, #444 0%, #222 100%);
}

.d, .e, .g, .a, .b {
	margin: 0 0 0 -1em;
}

ul li:first-child {
	border-radius: 5px 0 5px 5px;
}

ul li:last-child {
	border-radius: 0 5px 5px 5px;
}