header{
	margin:20px;
	padding:20px;
	position:absolute;
	left:;
	background-color:gray;
	width: 300px;
	height: auto;
	border: 1px solid black;
	}

.button {
  background-color: white;
  color: black;
  border: 1px solid black;
  border-radius: 4px;
}

.button:hover {
  background-color: black;
  color: white;
  border: 1px solid white;
  border-radius: 4px;
}
body {
	background-color: blue;
}
section {
		position: absolute;
		background-color: grey;
		width: 300px;
		height: auto;
		border: 1px solid black;
		padding: 20px;
		margin: 20px;
		top: 400px;
}