svg {
	margin:40px; /* give it some margin to show off the axes */
	overflow:visible; /* axes will extend beyond the svg cropping area.  Show them anyway */
}
#container { /* crop circles within axes */
	overflow: hidden;
}
svg circle {
	r:5; /* circles will have a default radius of 5 px */
	transition: r 0.5s ease-in-out, fill 0.5s linear; /* create transitions for radius and fill */
	transform-origin: 50% 50%; /* when transforming, do it around the center of the object */
}

circle:hover {
	fill:blue; /* when hovered, make the blue */
	r:15; /* make it larger when hovered */
}