h1 { text-align: center }
#wiringCallbacks button {
	display: block;
	width: 130px;
	text-align: center;
	margin: 10px auto;
	padding: 10px;
	border: 1px solid #000;
	background: #bbb;
}

#a01 , #a02 , #a03 {
	float: left;
	width: 33%;
	box-sizing: border-box;
	border: 1px solid #000;
	padding: 5px;
}