* {
  -webkit-box-sizing: border-box;
	 -moz-box-sizing: border-box;
		  box-sizing: border-box;
}
canvas, img {
	border: 1px solid black;
	image-rendering: pixelated;
}
input[type="checkbox"]{
	-webkit-appearance: none;
	-moz-appearance: none;
	appearance: none;
	border: 1px solid black;
	border-radius: 0;
	width: 24px;
	height: 24px;
	background-size: 100%;
	background-image: url('img/f0.png');
	vertical-align: middle;
	outline: none;
}
input[type="checkbox"]:checked{
	background-image: url('img/f1.png');
}