body {
    font-family: sans-serif;
    background-color: #f0f0f0;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

#container {
    background-color: #fff;
    padding: 20px 40px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    width: 80%;
    max-width: 600px;
}

h1, h2 {
    color: #444;
    border-bottom: 2px solid #eee;
    padding-bottom: 10px;
}

#my-info #my-id {
    font-weight: bold;
    color: #007bff;
}

#participants-list {
    list-style-type: none;
    padding: 0;
}

#participants-list li {
    background-color: #e9ecef;
    padding: 8px 12px;
    border-radius: 4px;
    margin-bottom: 5px;
}

#audio-container audio {
    display: none; /* 音声コントロールは表示しない */
}