/* In-app help: the page tree is hidden but its grid column stays reserved,
   pushing the article to the right. Collapse it and centre the article. */
html[data-in-app-help="true"] section.article-page {
  grid-template-columns: minmax(0, 1fr) !important;
  grid-template-areas: "article" !important;
}

html[data-in-app-help="true"] main.main-content {
  width: 100%;
  max-width: 860px;     /* tweak to taste — controls the reading width */
  margin-inline: auto;  /* centres it */
}