body {
    margin: 0;
    font-family: Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: #f0f0f0;
}

h1 {
    color: #333;
    margin-top: 20px;
}

.video-container {
    position: relative;
    width: 640px; /* 必要に応じて調整 */
    height: 480px; /* 必要に応じて調整 */
    margin-top: 20px;
    border: 2px solid #ccc;
    background-color: #000;
}

video,
canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

canvas {
    z-index: 1; /* キャンバスを動画の上に重ねる */
}