/* Blend only the existing floor/background at each product-to-river join. */
.offer-course:has(>.river-benefits){isolation:isolate}

/* The core display has only four unused native floor pixels at its cropped edge.
   Keep every product and mapped label above the river and fade only that floor. */
.river-system-crop{z-index:4}
.river-system-crop #system-stage>.offer-stage-art{
 -webkit-mask-image:linear-gradient(to bottom,#000 0 75.68075%,transparent 76.05634%);
 mask-image:linear-gradient(to bottom,#000 0 75.68075%,transparent 76.05634%);
}
.river-system-crop::after{content:"";position:absolute;left:0;right:0;bottom:0;height:1.35%;z-index:2;pointer-events:none;background:radial-gradient(ellipse at 51% 100%,#36ddff5c,transparent 65%);mix-blend-mode:screen}
.river-system-crop+.river-benefits{z-index:2;margin-top:-6%;background:transparent}
.river-system-crop+.river-benefits .river-stage-art{-webkit-mask-image:none;mask-image:none}

/* All three lower collections end their last physical object before native y=850.
   The overlap begins at y=893.44 of the unchanged 1536×1024 product stage. */
.offer-stage:is(.collection-kit,.training-kit){z-index:1}
.offer-stage:is(.collection-kit,.training-kit)::after{content:"";position:absolute;z-index:2;left:0;right:0;bottom:0;height:14%;pointer-events:none;background:radial-gradient(ellipse at 51% 100%,#00cfff35 0,transparent 67%);mix-blend-mode:screen}
.offer-stage:is(.collection-kit,.training-kit)+.river-benefits{z-index:2;margin-top:-8.5%;background:transparent}
.offer-stage:is(.collection-kit,.training-kit)+.river-benefits .river-stage-art{
 -webkit-mask-image:linear-gradient(to bottom,transparent,#000 14%);
 mask-image:linear-gradient(to bottom,transparent,#000 14%);
}

/* Shared soft blue reflections replace the previous opaque dark cap. */
.offer-course>.river-benefits::before{height:18%;background:radial-gradient(ellipse at 51% 0,#1ddfff35 0,transparent 64%),linear-gradient(to bottom,transparent,#093d6322 43%,transparent);mix-blend-mode:screen}
@media(max-width:720px){
 .offer-course>.river-benefits::before{height:58px}
 .offer-stage:is(.collection-kit,.training-kit)+.river-benefits .river-stage-art{
  -webkit-mask-image:linear-gradient(to bottom,transparent,#000 42px);
  mask-image:linear-gradient(to bottom,transparent,#000 42px);
 }
 /* Ease only the exterior rock lip before the first plaque's gold border. */
 .offer-course>.river-benefits .river-benefit:first-of-type .river-plaque-mobile{
  -webkit-mask-image:linear-gradient(to bottom,transparent,#000 2.7%);
  mask-image:linear-gradient(to bottom,transparent,#000 2.7%);
 }
}
/* Carry the same blue floor light through the CTA landing. */
.offer-course>.river-benefits::after{content:"";position:absolute;z-index:1;inset:auto 0 0;height:clamp(18px,2.3vw,45px);background:linear-gradient(transparent,#031329);pointer-events:none}
.offer-course>.river-benefits+.offer-course-action{background-image:linear-gradient(#031329,transparent 45%),url('assets/course-ground.webp')}