body {
    margin: 0;
    overflow: hidden;
    background: #1e1e1e;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    font-family: 'Courier New', Courier, monospace;
    color: #ffffff;
}
canvas {
    border: 2px solid #ffffff;
    background: #000000;
}
#startScreen, #gameOverScreen {
    position: absolute;
    border: 1px solid #ffffff;
    background: rgba(0, 0, 0, 0.8);
    color: #ffffff;
    text-align: center;
    padding: 20px;
    border-radius: 10px;
    display: none;
}
#startScreen {
    display: block;
}
#gameOverScreen {
    display: none;
}
#score {
    position: absolute;
    top: 20px;
    left: 20px;
    font-size: 24px;
    color: #00ff00;
}