body {
    font-family: sans-serif;
    text-align: center;
    background-color: #f0f0f0;
}

#game-container {
    position: relative;
    width: 300px;
    height: 400px;
    border: 2px solid #333;
    margin: 20px auto;
    background-color: #fff;
}

#score {
    font-size: 1.5em;
    font-weight: bold;
}

#timer {
    font-size: 1.5em;
    font-weight: bold;
    margin-bottom: 10px;
}

.hidden {
    display: none;
}