main {
    display: flex;
    flex-direction: column;
    align-items: center;
}

#gallery {
    display: flex;
    flex-direction: column;
    align-items: center;
}

#gallery>picture,
#gallery>video {
    margin: 1rem 0;
    width: 100%;
}

#gallery>picture>img {
    width: 100%;
    height: auto;
}