.mdn-html-embed {
    width: 100%;
    margin: 1.5rem auto;
    overflow-x: auto;
}

/* Most embed providers (Scribe included) return a responsive <iframe> with
   width:100%, but this covers cases where a fixed-width iframe is pasted in,
   so it never overflows the article column on mobile. */
.mdn-html-embed iframe {
    max-width: 100%;
}