Template:Infobox Ferret/doc/styles.css

.infobox-ferret-doc-example {
  display: flex;
  /* needed? */
  float: none;
}

/* original size Infobox */
.infobox-ferret-doc-example-infobox {
  flex: initial;
}

/* auto scaling textbox next to the Infobox */
.infobox-ferret-doc-example-textbox {
  flex: auto;
}