The Immersion Cinema backdrop: a warm radial glow bleeding from the
upper-right over the base --background, plus a subtle top scrim that
evokes the mockup's letterbox bar. Rendered once (in the locale layout)
as a fixed, aria-hidden layer behind all content. The glow is static —
no animation — so it is safe under prefers-reduced-motion.
The Immersion Cinema backdrop: a warm radial glow bleeding from the upper-right over the base
--background, plus a subtle top scrim that evokes the mockup's letterbox bar. Rendered once (in the locale layout) as a fixed,aria-hiddenlayer behind all content. The glow is static — no animation — so it is safe underprefers-reduced-motion.