/* Background refinement only: original padding, grids, cards and flow remain intact. */
.bg-material{--documentary-rgb:242 242 235}
.bg-material .bg-surface-visible::after{inset:0 auto 0 var(--bg-bleed-left,0px);width:var(--bg-viewport,100%);background-image:url('../textures/neutral-grain.svg');background-color:transparent;opacity:.09;z-index:-1;mask-image:linear-gradient(90deg,#000,transparent 20%,transparent 80%,#000);pointer-events:none}
.bg-material .bg-reading::after{display:block}
.bg-material .bg-protected::after{display:none}
.bg-material .bg-light{--bg-plane:linear-gradient(180deg,#f2f2eb,#fff)}
.bg-material .bg-exhibit,.bg-material .bg-dark{--documentary-rgb:45 74 54;--bg-plane:linear-gradient(180deg,#2d4a36,#203b2a)}
.bg-material .bg-reading{--documentary-rgb:255 255 255;--bg-plane:#fff}
.bg-material .bg-protected{--bg-plane:#fff}
/* Existing section padding carries a pale wash on narrow screens; centers stay opaque. */
@media(max-width:760px){
 .bg-material .bg-surface-visible::after{opacity:.075;mask-image:linear-gradient(90deg,#000,transparent 8%,transparent 92%,#000)}
}
@media(prefers-reduced-motion:reduce){.bg-material .bg-zone::before,.bg-material .bg-zone::after{animation:none!important;transition:none!important}}