body {
    margin: 0;
    background: #000;
    overflow: hidden;
    font-family: 'Arial', sans-serif;
}

#gameContainer {
    position: relative;
    width: 800px;
    height: 600px;
    margin: 20px auto;
}

#gameCanvas {
    background: #111;
    display: block;
    border: 2px solid #444;
}

#ui {
    position: absolute;
    top: 10px;
    left: 10px;
    color: #fff;
    font-size: 18px;
    text-shadow: 0 0 5px #0ff;
}

#startBtn {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    padding: 10px 30px;
    background: linear-gradient(#0af, #07f);
    border: none;
    color: white;
    font-size: 20px;
    border-radius: 5px;
    cursor: pointer;
    box-shadow: 0 0 10px #0af;
}

#startBtn:hover {
    background: linear-gradient(#0cf, #09f);
}