What's configured here (see config/page_level/showcase-header.config.php):

• header.appearance = 'transparent' — no background until you scroll, then fades to a solid dark bar.
• header.scrollBehaviour = 'hide-on-scroll' — the header hides on scroll-down and re-appears on scroll-up.
• header.navPosition = 'left' — the desktop nav sits to the left of the brand (mirrored from the site default).
• layout.showHero = true with hero.mediaWidth = 'full' — a full-bleed hero so the transparent header has something to sit over.

Still to review: the transparent-to-solid transition timing on slower scroll, and whether hide-on-scroll feels right when combined with a sticky mobile nav toggle.