body{
	background: #444	;

}

.cal{
	border:15px groove grey;
	width: 516px;
	margin: auto auto;
	background: #fff;
}



#btn{
	background: Coral;
	width: 100px;
	height: 60px;
	font-family: arial,verdana;
	font-weight: bold;
	text-align: center;
	font-size: 20px;
	margin-top: 3px;
}

#btn:hover{
	background: Tomato;
}
.pantalla{
	width: 510px;
	height: 60px;
	border:3px inset lightgrey;
	font-size: 30px;
	font-family: lucida console,arial;
	text-align: right;
	color: #000000; 

}