body {
    font-family: 'Nanum Gothic', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: #f0f0f0;
}

#game-container {
    text-align: center;
    background-color: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 0 20px rgba(0,0,0,0.1);
}

#game-area {
    width: 300px;
    height: 300px;
    background-color: #3498db;
    margin: 20px auto;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    cursor: pointer;
    color: white;
    border-radius: 10px;
    transition: background-color 0.3s;
}

#start-button {
    font-size: 18px;
    padding: 10px 20px;
    background-color: #2ecc71;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#start-button:hover {
    background-color: #27ae60;
}

#result {
    margin-top: 20px;
    font-size: 18px;
    font-weight: bold;
}

#reactionChart {
    margin-top: 30px;
}