html {
  font-size: 1vh;
  background: url(http://i.imgur.com/b9r5sEL.jpg) bottom center;
  background-size: cover; 
}

body,html {
  margin: 0;
  padding: 0;
  font-family: sans-serif;
}

.keys {
  display: flex;
  flex: 1;
  min-height: 100vh;
  align-items: center;
  justify-content: center;
}


.key{
	border: .4rem solid black;
	border-radius: .5rem;
	margin: 1rem;
	font-size: 1.5rem;
	padding: 1rem .5rem;
	transition: all .07s ease;
	width: 10rem;
	text-align: center;
	color: white;
	background: rgba(0,0,0,0.4);
	text-shadow: 0 0 .5rem black;
}

.playing {
  transform: scale(1.1);
  border-color: #ffc600;
  box-shadow: 0 0 1rem #ffc600;
}

kbd {
  display: block;
  font-size: 4rem;
}

.sound {
  font-size: 1.2rem;
  text-transform: uppercase;
  letter-spacing: .1rem;
  color: #ffc600;
}