The shared header dropdown is a reusable navigation example. It
groups real pages into columns, shows the current page, and adapts
to narrow screens. Open it with the button below or “Components
& pages” in the header.
Keyboard
Enter or Space opens it; Tab visits links. Escape closes and
returns focus to the opener. Tabbing outside also closes it.
Reuse
Markup: src/project/partials/mega-menu.html.
Behaviour: src/project/ts/mega-menu.ts. Use
semantic navigation links, not application-menu roles.