:root { color-scheme: dark; --overlay-bg: rgba(8, 8, 9, 0.88); --fg: #f5f5f7; --muted: #b8b8bf; /* ART-AR brand accent (gold), matching art-ar-platform's static/common.css - #F6C32C/#ffb40b there, same gradient stops. Both the primary button and the loading spinner read these two custom properties. A project's loading-screen branding redefines them (and the --brand-* properties used below) in a