.video-container {
    max-width: 600px;
    margin: 0 auto;
}

video {
    width: 100%;
    max-width: 600px;
    display: block;
    margin: 0 auto;
}

@media (max-width: 600px) {
    .video-container {
        max-width: 100%;
    }

    video {
        max-width: 100%;
    }
}