circle {
    r:5;
    fill: black;
    /*  transitions to make growing and changing color look nice */
    transition: r 0.5s linear, fill 0.5s linear;
}
#container {
    overflow: visible; /* make sure axes are visible  */
    margin-bottom: 50px; /* space below graph so table doesn't overlap */
}
body {
    /* move graph away from edge of screen */
    margin: 20px 40px;
}
table, th, td {
    /* make table cell borders visible  */
    border: 1px solid black;
}
th, td {
    /*  make table cels look better */
    padding:10px;
    text-align: center;
}
/* hover state for circles */
circle:hover {
    r:10;
    fill: blue;
}
/*  styles for circles when you click on them */
circle:active {
    fill: red;
}