.wp-block-media-text.is-image-fill figure.wp-block-media-text__media {
    position: relative;
}
.wp-block-media-text.is-image-fill figure.wp-block-media-text__media video {
    position: absolute;
    top: 0px;
    left: 0px;
    right: 0px;
    bottom: 0px;
    object-fit: cover;
    object-position: center;
    width: 100%;
    height: 100%;
}