.axis path,
.axis line {
	fill: none;
	stroke: black;
	shape-rendering: crispEdges;
}

.axis text {
	font-family: sans-serif;
	font-size: 11px;
}

.d3-tip {
	background-color: rgba(51, 51, 51, 0.9);
	border-radius: 5px;
	border: 1px solid #000;
	color: #f0f0f0;
	font-size: 80%;
	padding: 0.5em;
	max-width: 25em;
}
.d3-tip:after {
	display: block;
	content: " ";
	position: absolute;
	top: 100%;
	left: 50%;
	margin-left: -5px;
	border: 5px solid transparent;
	border-width: 10px 5px 0 5px;
	border-top-color: #000;
}
table { border-collapse: collapse; width: 100% }
td, th { border: 1px solid #aaa }
th { background-color: #ddd }