html { height: 100%; }

body {
	min-height: 100%;
	display: flex;
	flex-direction: column;
	overflow-y: scroll;
	overflow-x: hidden;
}

main { flex: 1 0 auto; }

header, footer {
	flex-shrink: 0;
}

details summary:after {
	transform: rotate(180deg);
}

.text-center { text-align: center; }

.send-button {
	justify-self: center;
    grid-column: 1 / 2;
    width: 50%;
}