body {
    margin: 0;
    overflow: hidden;
    font-family: 'Arial', sans-serif;
    background-color: #000;
    color: #fff;
    text-align: center;
}
#gameCanvas {
    display: block;
    margin: 0 auto;
    background: #111;
    border: 2px solid #0f0;
}
#instructions {
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
}
#score {
    position: absolute;
    top: 50px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
    font-size: 24px;
}