html {
	background-color: black;
}

html, body, main {
	height: 100%;
}

.main {
	display: flex;
	flex-direction: column;
	align-items: center;
	justify-content: center;
	gap: 30px;
}

/* LIGHTBULB */

.lightbulb {
	width: 50vmin;
	height: 50vmin;
	border-radius: 50%;
	background-color: darkslategray;
}

.lightbulb.is-on {
	background-color: yellow;
	box-shadow: 0 0 10vmin yellow;
}

button[name="on"] { 
	color: blue;
}