body {
    font-family: sans-serif;
    text-align: center;
}

.tooltip {
    position: absolute;
    text-align: center;
    padding: 5px;
    font-size: 12px;
    background: lightgray;
    border: 1px solid gray;
    border-radius: 5px;
    pointer-events: none;
}

.dot {
    fill: steelblue;
    stroke: black;
    stroke-width: 1px;
}