style.css

body {
	margin: 20px;
	background: #FFF;
	font-family: sans-serif;
}
main {
	display: grid;
	width: 100%;
	grid-template-columns: .6fr 1.4fr;
	grid-gap: 20px;
}
iframe {
	border: 1px solid #777;
	width: 100%;
	margin-top: 20px;
	border-radius: 3px;
}

h1 {
	margin: 0;
}
#about {
	display: block;
	margin: 0 0 30px;
}
h2 {
	margin-top: 0;
}

label {
	display: inline-block;
	margin-top: 6px;
}
input[type=url] {
	width: 100%;
	box-sizing: border-box;
}
input[type=url], select {
	padding: 4px 6px;
	background-color: inherit;
	font: inherit;
	font-size: .9em;
	border: 1px solid #777;
	border-radius: 3px;
}
input[type=color], button {
	padding: 4px 6px;
	border: 1px solid #777;
	border-radius: 3px;
	background: none;
}

@media screen and (max-width: 650px) {
	main {
		display: block;
	}
	#embed {
		margin-top: 20px;
	}
}