style.css

:root {
	--white: #fff;
	--black: #000;
	--github-fill: var(--white);
	--github-color: var(--black);
}

* {
	margin: 0;
	padding: 0;
	box-sizing: border-box;
}

body {
	min-height: 1500vh;
}

.github-corner {
	z-index: 9000;
}

#space {
	display: inline-block;
	width: 0;
}

.banner {
	display: inline-block;
	position: fixed;
	width: 100%;
	height: 100vh;
}

.banner video {
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	object-fit: cover;
}

.github-corner:focus svg path {
	fill: var(--black);
}

.github-corner:focus .octo-arm,
.github-corner:focus .octo-body {
	fill: var(--white);
}

.github-corner:hover .octo-arm,
.github-corner:focus .octo-arm {
	animation: octocat-wave 560ms ease-in-out;
}

@keyframes octocat-wave {
	0%,
	100% {
		transform: rotate(0);
	}

	20%,
	60% {
		transform: rotate(-25deg);
	}

	40%,
	80% {
		transform: rotate(10deg);
	}
}

@media (max-width: 500px) {
	.github-corner:hover .octo-arm {
		animation: none;
	}

	.github-corner .octo-arm {
		animation: octocat-wave 560ms ease-in-out;
	}
}