body { margin: 0; background-color: black; overflow: hidden; font-family: sans-serif; }
canvas { display: block; }
#tooltip {
    position: absolute;
    background: rgba(255, 255, 255, 0.9);
    color: black;
    padding: 5px 10px;
    border-radius: 4px;
    pointer-events: none;
    display: none;
    font-size: 16px;
    font-weight: bold;
    z-index: 10;
}