#turnOverlay.book-sheet { perspective:none; transform-style:flat; z-index:50; }
.book-beneath,.book-front,.book-back {position:absolute;inset:0;overflow:hidden;background:var(--bg);transform-origin:0 0;}
#turnOverlay.book-sheet .page {position:absolute;inset:0;width:100%;height:100%;margin:0;}
#turnOverlay.book-sheet .media img,#turnOverlay.book-sheet .prose > * {opacity:1;transform:none;transition:none;}
.book-front {z-index:1;will-change:clip-path;}
.book-shadow {position:absolute;left:0;top:0;z-index:2;transform-origin:0 50%;background:linear-gradient(90deg,rgba(0,0,0,.42),rgba(0,0,0,.13) 35%,transparent);pointer-events:none;}
.book-back {z-index:3;will-change:transform,clip-path;background:#101218;}
.book-back > .page {opacity:.055;filter:saturate(.6);}
.book-back::after {content:'';position:absolute;inset:0;background:linear-gradient(110deg,rgba(255,255,255,.012),rgba(255,255,255,.025) 65%,rgba(0,0,0,.1));}
.book-sheen {position:absolute;left:0;top:0;z-index:4;transform-origin:100% 50%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.025) 45%,rgba(255,255,255,.11) 84%,rgba(0,0,0,.22));pointer-events:none;}