.caixa {
	width: 300px;
	height: 200px;
	background-color: green;
	margin: 50px;
	box-shadow: 10px 10px 20px rgba(0,0,0,0.3);
	padding: 20px;
	font-size: 20px;
	text-align: center;
}

h1{
  text-align: center;
}