header {
	display: flex;
	flex-flow: row wrap;
	align-items: center;
	justify-content: center;
}

header * {
	flex: 3;
}

header img {
	flex: 1;
}

nav, footer {
	flex: 1 100%;
}

nav a {
	margin-right: 2em;
}

body h1 {
	margin-top: 2em;
}

section {
	border-top: 2px solid blue;
	margin-top: 2em;
}