style.css

.container {
	align-content: center;
}

canvas {
	min-width: 300px;
	min-height: 500px;
	padding: 5px 10px;
	margin: 20px 0 10px;
	border: 2px solid #ccc;
    border-radius: 5px;
	position: relative;
}

.score {
	padding: 5px 10px;
	background-color: #ccc;
	border-radius: 5px;
	font-weight: bold;
}

.score span {
	font-weight: normal;
}

#game-over-screen {
	background-color: white;
	border: 4px solid grey;
	border-radius: 7px;
	color: red;
	float: left;
	font-size: 3em;
	font-weight: bold;
	margin: 20px;
	overflow-x: visible;
	padding: 10px 15px;
	position: absolute;
	text-align: center;
	top: 200px;
	visibility: hidden;
}

footer {
	width: 100%;
	position: fixed;
	bottom: 0;
	background-color: #aaa;
	color: white;
	text-align: center;
}

header {
	background-color: rgb(204, 204, 204);
	color: rgb(51, 51, 51);
}

header h1 {
	font-weight: bold;
}