body {
    margin: 0;
    overflow: hidden;
    background-color: #111;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

#ui-layer {
    position: absolute;
    top: 20px;
    left: 20px;
    color: white;
    pointer-events: none;
    user-select: none;
}

#speed-meter {
    font-size: 2rem;
    font-weight: bold;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}