body{
			text-align: center;
}
button{
	width: 4em;
	font-weight: bold;
	font-size: 16px;
}
.contenedor{
	display: flex;
	justify-content: center;
}
.calculadora{
	background-color: #C0D9D9;
	width: 500px;
	margin: auto;
}
@media screen and (max-width: 500px){
	.calculadora{
		width: 100%;
	}