img.responsive-img,
video.responsive-video {
    max-width: 100%;
    height: auto;
}

figcaption {
    font-size: 0.8em;
    text-align: center;
}

.twitter-tweet {
    margin-left: auto;
    margin-right: auto;
}

h4.h4-caption {
    font-size: 1em;
    margin-top: 0.25em;
}