body {
	font-family: Arial, Helvetica, sans-serif;
	text-align: center;
}

#errors {
	color: coral;
}

#timer {
	color: blueviolet;
}

.number-selected {
	background-color: gray;
}

.number-removed {
	background-color: black;
}

.tile-start {
	background-color: whitesmoke;
}

.number-highlighted {
	background-color: beige;
}

hr {
	width: 450px;
}

.tile {
	width: 48px;
	height: 48px;
	border: 1px solid lightgray;
	
	/* Text */
	font-size: 20px;
	font-weight: bold;
	display: flex;
	justify-content: center;
	align-items: center;
}

#board {
	width: 450px;
	height: 450px;
		
	margin: 0 auto;
	display: flex;
	flex-wrap: wrap;
}

#digits {
	width: 450px;
	height: 450px;
		
	margin: 0 auto;
	display: flex;
	flex-wrap: wrap;
}

.number {
	width: 44px;
	height: 44px;
	border: 1px solid black;
	margin: 2px;
	
	/* Text */
	font-size: 20px;
	font-weight: bold;
	display: flex;
	justify-content: center;
	align-items: center;
}

.horizontal-line {
	border-bottom: 1px solid black;
}

.vertical-line {
	border-right: 1px solid black;
}

/* iPhone [portrait + landscape] */
@media only screen and (max-device-width: 480px) {
	hr {
		width: 405px;
	}
	
	.tile {
		width: 43px;
		height: 43px;
	}
	
	#board {
		width: 405px;
		height: 405px;
	}
	
	#digits {
		width: 405px;
		height: 405px;
	}
	
	.number {
		width: 39px;
		height: 39px;
	}
}