site.css

@import url(https://fonts.googleapis.com/css?family=Press+Start+2P);

*, *::before, *::after {
	box-sizing: border-box;
}

html {
	font-size: 6px;
}

@media screen and (min-width: 640px) and (min-height: 400px) {
	html { font-size: 10px; }
}
@media screen and (min-width: 768px) and (min-height: 540px) {
	html { font-size: 14px; }
}
@media screen and (min-width: 832px) and (min-height: 620px) {
	html { font-size: 16px; }
}

body {
	margin: 0;
	color: #fff;
	background-color: #4b6473;
	background-image: url(images/stars1.png), url(images/stars2.png), url(images/stars3.png);
	background-position: 0 0, 0 0, 0 0; /* firefox needs this */
	font: 2rem 'Press Start 2P', monospace;
	text-transform: uppercase;
	overflow: hidden;
}

.fly-up {
	background-position: 0 4096px, 0 8192px, 0 16384px;
	transition: background-position 11.8s ease;
	animation: space-darken 11.8s steps(8) forwards;
}

.fly-across {
	background-color: #1d272d;
	animation: stars-fly-across 8s linear infinite;
}

.get-ready {
	position: absolute;
	top: 50%;
	left: 50%;
	transform: translate(-50%, -50%);
}

.splash {
	display: none;
	position: absolute;
	top: 50%;
	left: 50%;
	transform: translate(-50%, -50%);
	width: calc(100% - 6rem);
	text-align: center;
}

.title {
	margin: 0 0 2rem;
	font-size: 6rem;
	line-height: 1.5;
}

.start {
	margin: 0;
	padding: 1rem 2rem;
	border: 0.5rem solid #fff;
	border-radius: 0;
	color: #fff;
	background-color: #f89f1b;
	font: inherit;
	text-transform: inherit;
	cursor: pointer;
	-webkit-appearance: none;
	-moz-appearance: none;
	appearance: none;
}

.start:disabled {
	visibility: hidden;
}

.toast {
	display: none;
	position: absolute;
	top: 25%;
	left: 50%;
	margin: -64px 0 0 -64px;
	animation: fade-in 4s steps(4), toast-bob 6s ease infinite;
}

.dialog {
	display: none;
	position: absolute;
	top: calc(75% - 8.5rem);
	left: calc(50% - 24rem);
	width: 48rem;
	height: 17rem;
	padding: 2rem;
	border: solid 0.5rem #000;
	color: #000;
	background-color: #fff;
	line-height: 2;
	white-space: pre;
	overflow: hidden;
	animation: dialog-grow-in 1s linear;
}

.the-end {
	display: none;
	position: absolute;
	top: calc(75%);
	left: 50%;
	transform: translate(-50%, -50%);
	width: calc(100% - 6rem);
	margin: 0 0 2rem;
	text-align: center;
	font-size: 6rem;
	line-height: 1.5;
	animation: fade-in 4s steps(4);
}

@keyframes fade-in {
	0% { opacity: 0; }
	100% { opacity: 1; }
}

@keyframes dialog-grow-in {
	0% { transform: scaleY(0); }
	100% { transform: scaleY(1); }
}

@keyframes toast-bob {
	50% { transform: translateY(4rem); }
	100% { transform: translateY(0); }
}

@keyframes space-darken {
	100% { background-color: #1d272d; }
}

@keyframes stars-fly-across {
	100% { background-position: -2048px 512px, -4096px 512px, -8192px 512px; }
}