5.1 – Title and collapsing

Heading

options:
  title: About this handbook

That becomes an h3 with the class layout-box-title — the same level the explorer and the table of contents use for their headings, so that the page’s outline stays sound.

Placeholders work here too: title: "About {{siteTitle}}".

Collapsing

options:
  title: About this handbook
  collapsible: true
  collapsed: false

collapsible turns the box into a details element whose clickable line is the title. collapsed decides whether it starts closed. The box at the bottom left of this site is built exactly that way — only with collapsed: true, so it starts closed.

collapsible without title does not work

A details with no line to click could not be opened. The plugin says so at build time — “collapsible requires a title; rendering non-collapsible” — and renders the box normally.

The message only appears when collapsible comes from the configuration, from the base options or from byLang. From a page’s frontmatter it stays away: the box is not collapsible there either, but without a word.

No JavaScript, with the consequences

Opening and closing is the built-in behaviour of details. No script, no load time, and it works with JavaScript switched off.

The price: the state does not survive a page change. Open the box, click on, and the next page shows it the way collapsed says. Anything else would need a script and browser storage — and then it would no longer be a plugin that ships nothing.

Start closed when the box is long

In a narrow column an open box pushes everything below it out of sight. collapsed: true is usually the friendlier choice there — the title says what is inside, after all.