/* ==========================================================
   FRANJA "CASO REAL" — expediente de una pieza: fabricación -> verificación -> resultado.
   Tres evidencias a la misma altura (dos vídeos y una foto) + ficha del trabajo. Móvil: tira lateral con snap.
   ========================================================== */
.cas{position:relative;background:var(--grafito);padding:clamp(80px,12vh,140px) 0 clamp(72px,10vh,120px);overflow:hidden;
  }
.cas__head{max-width:1320px;margin:0 auto clamp(40px,7vh,76px);padding:0 clamp(24px,4vw,56px)}
.cas__eyebrow{font-family:var(--mono);font-size:11px;letter-spacing:.28em;text-transform:uppercase;color:var(--azul-luz);margin:0 0 18px}
.cas__h2{margin:0;font-weight:300;font-size:clamp(32px,3.7vw,60px);line-height:1.05;letter-spacing:-.012em;color:var(--hueso)}
.cas__h2 span{display:block}
.cas__h2 em{font-style:normal;background:linear-gradient(90deg,var(--azul),#4fd0ff);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;color:transparent;padding-bottom:.06em}
.cas__sub{margin:18px 0 0;max-width:58ch;font-family:Inter,system-ui,sans-serif;font-size:clamp(14px,1.1vw,16px);line-height:1.6;color:var(--acero)}

.cas__strip{--h:clamp(230px,24vw,345px);max-width:1320px;margin:0 auto;padding:0 clamp(24px,4vw,56px);display:flex;justify-content:center;align-items:flex-start;gap:36px}
.cas__ev{position:relative;margin:0;flex:none}
.cas__ev--a,.cas__ev--c{width:calc(var(--h) * 4 / 3)}
.cas__ev--b{width:calc(var(--h) * 9 / 16)}
.cas__media{position:relative;height:var(--h);border-radius:10px;overflow:hidden;background:#0a0d12;border:1px solid rgba(255,255,255,.12);
  box-shadow:0 30px 60px -26px rgba(0,0,0,.9),0 0 60px -18px var(--azul-glow)}
.cas__media video,.cas__media img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;display:block}
.cas__ev:not(:last-child)::after{content:"";position:absolute;top:calc(var(--h) / 2 - 8px);right:-27px;width:18px;height:16px;
  background:no-repeat center/contain url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 16' fill='none' stroke='%233fa4ff' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M2 8h13M10 2l6 6-6 6'/%3E%3C/svg%3E")}
.cas__ev figcaption{margin-top:14px;display:flex;flex-direction:column;gap:4px}
.cas__k{font-family:var(--mono);font-size:10.5px;letter-spacing:.22em;text-transform:uppercase;color:var(--azul-luz)}
.cas__c{margin:0;font-weight:400;font-size:clamp(16px,1.35vw,20px);line-height:1.25;color:var(--hueso)}

.cas__ficha{max-width:1320px;margin:clamp(44px,7vh,72px) auto 0;padding:clamp(22px,3vw,32px) clamp(24px,4vw,56px) 0;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:26px clamp(20px,3vw,48px);position:relative}
.cas__ficha::before{content:"";position:absolute;left:clamp(24px,4vw,56px);right:clamp(24px,4vw,56px);top:0;height:1px;background:var(--linea)}
.cas__ficha dt{font-family:var(--mono);font-size:10px;letter-spacing:.2em;text-transform:uppercase;color:var(--acero);margin:0 0 6px}
.cas__ficha dd{margin:0;font-family:var(--cond);font-weight:400;font-size:clamp(20px,1.8vw,26px);line-height:1.15;color:var(--hueso)}
.cas__tbd{color:var(--acero);font-weight:300;border-bottom:1px dashed var(--azul);padding-bottom:1px}
.cas__foot{max-width:1320px;margin:clamp(44px,7vh,72px) auto 0;padding:0 clamp(24px,4vw,56px);display:flex;align-items:center;justify-content:center;gap:22px 34px;flex-wrap:wrap}
.cas__lead{margin:0;font-weight:300;font-size:clamp(22px,2vw,30px);color:var(--hueso)}

/* entrada */
.cas.is-pre .cas__ev,.cas.is-pre .cas__ficha{opacity:0;transform:translateY(22px)}
.cas .cas__ev,.cas .cas__ficha{transition:opacity .8s cubic-bezier(.2,.7,.2,1),transform .9s cubic-bezier(.2,.7,.2,1)}
.cas.is-in .cas__ev:nth-child(2){transition-delay:.12s}.cas.is-in .cas__ev:nth-child(3){transition-delay:.24s}.cas.is-in .cas__ficha{transition-delay:.34s}

@media(min-width:761px) and (max-width:1000px){.cas__strip{gap:30px}.cas__ev:not(:last-child)::after{right:-24px}.cas__ficha{grid-template-columns:repeat(2,minmax(0,1fr))}}
/* móvil: tira lateral con snap */
@media(max-width:760px){
  .cas{padding:34px 0 48px}
  .cas__head{margin-bottom:26px}
  .cas__h2{font-size:clamp(32px,9.6vw,42px)}
  .cas__strip{--h:min(56vw,280px);justify-content:flex-start;overflow-x:auto;scroll-snap-type:x mandatory;scroll-padding:0 24px;padding:6px 24px 8px;gap:30px;scrollbar-width:none}
  .cas__strip::-webkit-scrollbar{display:none}
  .cas__ev{scroll-snap-align:start}
  .cas__ev:not(:last-child)::after{right:-24px}
  .cas__ficha{grid-template-columns:repeat(2,minmax(0,1fr));margin-top:34px}
  .cas__foot{margin-top:34px;flex-direction:column;align-items:stretch;text-align:center}
  .cas__foot .btn{justify-content:center}
}
@media(prefers-reduced-motion:reduce){.cas .cas__ev,.cas .cas__ficha{transition:none!important}.cas.is-pre .cas__ev,.cas.is-pre .cas__ficha{opacity:1;transform:none}}

/* texto de cada paso: visible solo en la versión con scroll; en el resto queda en el HTML pero recortado */
.cas__p{position:absolute;width:1px;height:1px;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ESCRITORIO (≥900px, JS activo y sin movimiento reducido): los pasos se desplazan a la izquierda
   y la evidencia queda fija a la derecha, cambiando con cada paso. */
@media(min-width:900px){
  .cas--scroll .cas__strip{--h:clamp(340px,58vh,520px);display:grid;grid-template-columns:minmax(0,.8fr) minmax(0,1.2fr);
    grid-template-rows:repeat(3,minmax(clamp(380px,62vh,600px),auto));column-gap:clamp(40px,6vw,96px);justify-content:stretch;align-items:stretch}
  .cas--scroll .cas__ev{display:contents}
  .cas--scroll .cas__ev::after{content:none}
  .cas--scroll .cas__media{grid-column:2;grid-row:1/-1;position:sticky;top:calc(50vh - var(--h) / 2);align-self:start;justify-self:center;height:var(--h);
    opacity:0;visibility:hidden;transform:scale(.97);transition:opacity .7s cubic-bezier(.2,.7,.2,1),transform .9s cubic-bezier(.2,.7,.2,1),visibility 0s .7s}
  .cas--scroll .cas__ev--a .cas__media,.cas--scroll .cas__ev--c .cas__media{width:min(100%,calc(var(--h) * 4 / 3))}
  .cas--scroll .cas__ev--b .cas__media{width:calc(var(--h) * 9 / 16)}
  .cas--scroll .cas__ev.is-active .cas__media{opacity:1;visibility:visible;transform:none;transition:opacity .7s cubic-bezier(.2,.7,.2,1),transform .9s cubic-bezier(.2,.7,.2,1),visibility 0s}
  .cas--scroll .cas__ev--a figcaption{grid-row:1}.cas--scroll .cas__ev--b figcaption{grid-row:2}.cas--scroll .cas__ev--c figcaption{grid-row:3}
  .cas--scroll .cas__ev figcaption{grid-column:1;align-self:center;margin:0;gap:10px;padding:6px 0 6px 28px;border-left:1px solid var(--linea);opacity:.3;transition:opacity .5s,border-color .5s}
  .cas--scroll .cas__ev.is-active figcaption{opacity:1;border-left-color:var(--azul);box-shadow:-1px 0 0 0 var(--azul),-8px 0 18px -10px var(--azul-glow)}
  .cas--scroll{overflow:clip}
  .cas--scroll .cas__k::before{color:var(--acero)}
  .cas--scroll .cas__ev--a .cas__k::before{content:"01  ·  "}.cas--scroll .cas__ev--b .cas__k::before{content:"02  ·  "}.cas--scroll .cas__ev--c .cas__k::before{content:"03  ·  "}
  .cas--scroll .cas__c{font-weight:300;font-size:clamp(26px,2.6vw,40px);line-height:1.12;letter-spacing:-.008em}
  .cas--scroll .cas__p{position:static;width:auto;height:auto;margin:6px 0 0;overflow:visible;clip:auto;white-space:normal;max-width:36ch;font-family:Inter,system-ui,sans-serif;font-size:clamp(14px,1.1vw,16px);line-height:1.6;color:var(--acero)}
  .cas--scroll.is-pre .cas__ev{opacity:1;transform:none}
}

/* fondo: rejilla técnica fina + luz azul que se desplaza con el scroll */
.cas::before{content:"";position:absolute;inset:0;pointer-events:none;z-index:0;
  background-image:linear-gradient(rgba(120,170,230,.07) 1px,transparent 1px),linear-gradient(90deg,rgba(120,170,230,.07) 1px,transparent 1px);background-size:72px 72px;background-position:center top;
  -webkit-mask-image:radial-gradient(ellipse 80% 70% at 62% 50%,#000 10%,transparent 78%);mask-image:radial-gradient(ellipse 80% 70% at 62% 50%,#000 10%,transparent 78%)}
.cas::after{content:"";position:absolute;z-index:0;pointer-events:none;right:-8%;top:calc(var(--p,.4) * 100%);width:min(900px,70vw);aspect-ratio:1;transform:translateY(-50%);
  background:radial-gradient(circle,rgba(0,134,255,.2),rgba(0,134,255,.06) 45%,transparent 70%)}
.cas>*{position:relative;z-index:1}

/* hilo fino que une los pasos y se rellena con el scroll */
@media(min-width:900px){
  .cas--scroll .cas__strip{position:relative}
  .cas--scroll .cas__ev figcaption,.cas--scroll .cas__ev.is-active figcaption{border-left:0;box-shadow:none;position:relative}
  .cas--scroll .cas__rail{position:absolute;left:clamp(24px,4vw,56px);top:var(--rt,0);height:var(--rh,0);width:0;pointer-events:none;z-index:2}
  .cas--scroll .cas__rail::before{content:"";position:absolute;left:0;top:0;bottom:0;width:1px;background:var(--linea)}
  .cas--scroll .cas__rail::after{content:"";position:absolute;left:0;top:0;width:1px;height:var(--fy,0px);background:var(--azul);box-shadow:0 0 10px var(--azul-glow)}
  .cas--scroll .cas__ev figcaption::before{content:"";position:absolute;left:0;top:50%;width:14px;height:1px;background:var(--linea);transition:background .4s,width .4s}
  .cas--scroll .cas__ev figcaption.is-done::before{background:var(--azul);width:20px}
  .cas--scroll .cas__k::before{content:none!important}
}