:root {
  --vino: #900813; --vino-hondo: #760710; --tinta: #191817; --papel: #FBFAF7; --crema: #F2EFE9;
  --gris: #5F5A55; --gris-claro: #B9B3AC; --regla: rgba(25, 24, 23, .13);
  --mesa: #1f1d1c; --mesa-borde: rgba(251, 250, 247, .12);
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { height: 100%; }
body {
  margin: 0; background: #0b0a0a; color: var(--tinta);
  font: 400 16px/1.55 Raleway, "Helvetica Neue", Arial, sans-serif; font-feature-settings: "lnum" 1;
  -webkit-text-size-adjust: 100%;
}
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
button { font: inherit; color: inherit; cursor: pointer; }

/* ------------------------------------------------ entrada (fondo negro + el libro en 3D) */
.entrada {
  min-height: 100svh; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); align-items: center;
  gap: clamp(32px, 6vw, 96px); padding: clamp(40px, 7vw, 96px) max(16px, 5vw);
  background: radial-gradient(60% 55% at 28% 50%, rgba(144, 8, 19, .28), transparent 70%), #0b0a0a; color: var(--papel);
}
.escena { display: grid; place-items: center; perspective: 1900px; justify-self: end; }
.tomo {
  --w: clamp(220px, 27vw, 380px); --h: calc(var(--w) * 1.29); --t: calc(var(--w) * .17);
  position: relative; width: var(--w); height: var(--h); transform-style: preserve-3d;
  transform: rotateX(6deg) rotateY(-36deg); animation: flotar 7s ease-in-out infinite;
}
@keyframes flotar { 50% { transform: rotateX(4deg) rotateY(-30deg) translateY(-8px); } }
.cara-tomo { position: absolute; }
/* Pasta dura: la tapa sobresale un poco del bloque de hojas y tiene la bisagra marcada. */
.frente-tomo {
  inset: 0; transform: translateZ(calc(var(--t) / 2)); border-radius: 2px 5px 5px 2px;
  background: linear-gradient(90deg, rgba(0,0,0,.55) 0, rgba(255,255,255,.08) 2.2%, rgba(0,0,0,.35) 3.6%, transparent 7%),
    linear-gradient(105deg, rgba(255,255,255,.10), transparent 40%), url(portada.webp) center / cover, #111;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.06);
}
.atras-tomo { inset: 0; transform: rotateY(180deg) translateZ(calc(var(--t) / 2)); background: #120c0c; border-radius: 5px 2px 2px 5px; }
.lomo-tomo {
  top: 0; left: calc(50% - var(--t) / 2); width: var(--t); height: 100%;
  transform: rotateY(-90deg) translateZ(calc(var(--w) / 2));
  background: linear-gradient(90deg, #170d0d, #3a0d10 30%, #4d1015 50%, #3a0d10 70%, #170d0d);
  display: grid; place-items: center; overflow: hidden;
}
.lomo-tomo span {
  writing-mode: vertical-rl; transform: rotate(180deg); white-space: nowrap; color: rgba(251,250,247,.82);
  font: 500 calc(var(--t) * .3)/1 Unbounded, sans-serif; letter-spacing: .12em; text-transform: uppercase;
}
.cantos-tomo {
  top: 0; left: calc(50% - var(--t) / 2); width: var(--t); height: 100%;
  transform: rotateY(90deg) translateZ(calc(var(--w) / 2 - 2px));
  background: repeating-linear-gradient(90deg, #efe9dd 0 1px, #d9d1c2 1px 2px), #ece6da;
  border-inline: 5px solid #1c1313; /* el grueso de las dos pastas */
  box-shadow: inset 6px 0 10px -4px rgba(0,0,0,.35), inset -4px 0 6px -3px rgba(0,0,0,.25);
}
.arriba-tomo {
  left: 0; top: calc(50% - var(--t) / 2); width: calc(100% - 2px); height: var(--t);
  transform: rotateX(90deg) translateZ(calc(var(--h) / 2 - 2px));
  background: repeating-linear-gradient(0deg, #f3eee4 0 1px, #dcd4c5 1px 2px);
  border-block: 5px solid #1c1313;
}
.sombra-tomo {
  width: calc(clamp(220px, 27vw, 380px) * 1.05); height: 34px; margin-top: 18px; border-radius: 50%;
  background: radial-gradient(closest-side, rgba(0,0,0,.85), transparent); filter: blur(6px); transform: translateX(-6%);
}

.tarjeta { width: 100%; max-width: 420px; justify-self: start; }
.sobre { margin: 0 0 16px; font: 500 .7rem/1.2 Unbounded, sans-serif; letter-spacing: .16em; text-transform: uppercase; color: #e0706f; }
h1 { margin: 0 0 16px; font: 400 clamp(2.3rem, 4.6vw, 3.4rem)/1 "Gilda Display", Georgia, serif; letter-spacing: -.01em; text-wrap: balance; }
.nota { margin: 0 0 30px; color: var(--gris-claro); }
.paso { display: grid; gap: 10px; }
label { font-weight: 600; font-size: .9rem; color: var(--papel); }
input[type=email], input[type=text] {
  width: 100%; font: inherit; font-size: 1.05rem; padding: 15px 16px; border: 1px solid rgba(251,250,247,.22);
  background: rgba(251,250,247,.06); color: var(--papel); border-radius: 2px; outline: none;
}
input::placeholder { color: rgba(251,250,247,.38); }
input:focus-visible { border-color: #e0706f; box-shadow: 0 0 0 3px rgba(224, 112, 111, .22); }
#codigo { letter-spacing: .4em; font-size: 1.4rem; text-align: center; }
.boton {
  margin-top: 8px; border: 0; background: var(--vino); color: var(--papel); padding: 1.2em 1.4em; border-radius: 2px;
  font: 600 .8rem/1 Raleway, sans-serif; letter-spacing: .18em; text-transform: uppercase;
  transition: background .2s, transform .15s;
}
.boton:hover { background: #a80a17; }
.boton:active { transform: translateY(1px); }
.boton:disabled { opacity: .6; cursor: progress; }
.enlace { border: 0; background: none; padding: 6px 0; color: var(--gris-claro); text-decoration: underline; justify-self: start; font-size: .9rem; }
.mensaje { min-height: 1.5em; margin: 16px 0 0; font-size: .95rem; color: var(--gris-claro); }
.mensaje.error { color: #f08a89; }
.ayuda { margin: 20px 0 0; padding-top: 18px; border-top: 1px solid rgba(251,250,247,.12); font-size: .82rem; color: rgba(251,250,247,.5); }
.ayuda a { color: var(--papel); }

@media (max-width: 760px) {
  .entrada { grid-template-columns: minmax(0, 1fr); gap: 28px; padding-top: 48px; align-content: start; }
  .escena { justify-self: center; }
  .tomo { --w: min(52vw, 220px); }
  .sombra-tomo { width: min(56vw, 236px); height: 22px; margin-top: 12px; }
  .tarjeta { justify-self: center; text-align: left; }
}
@media (prefers-reduced-motion: reduce) { .tomo { animation: none; } }

/* ------------------------------------------------ lector */
.lector {
  position: fixed; inset: 0; display: grid; grid-template-rows: auto minmax(0, 1fr) auto; grid-template-columns: minmax(0, 1fr);
  background: var(--mesa); color: var(--papel);
  -webkit-user-select: none; user-select: none; -webkit-touch-callout: none;
}
.barra-alta, .barra-baja {
  display: flex; align-items: center; gap: 16px; padding: 10px max(16px, env(safe-area-inset-left));
  padding-right: max(16px, env(safe-area-inset-right));
}
.barra-alta { justify-content: space-between; border-bottom: 1px solid var(--mesa-borde); }
.titulo { flex: 1; min-width: 0; font: 400 1.05rem/1.2 "Gilda Display", Georgia, serif; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.acciones { display: flex; align-items: center; gap: 4px; flex: none; }
.icono, .texto { border: 0; background: none; color: var(--papel); min-width: 44px; min-height: 44px; display: grid; place-items: center; border-radius: 6px; }
.texto { padding: 0 12px; font-size: .85rem; letter-spacing: .06em; }
.icono:hover, .texto:hover, .icono[aria-pressed=true] { background: rgba(251, 250, 247, .1); }
.icono svg, .lado svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }

.escenario { position: relative; overflow: hidden; touch-action: pan-y pinch-zoom; }
.libro { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; perspective: 2400px; }
.hoja { position: relative; background: var(--papel); box-shadow: 0 18px 40px -18px rgba(0, 0, 0, .7); }
.hoja canvas { display: block; width: 100%; height: 100%; }
.hoja.cargando::after {
  content: ""; position: absolute; inset: 0; margin: auto; width: 28px; height: 28px; border-radius: 50%;
  border: 2px solid var(--regla); border-top-color: var(--vino); animation: girar .8s linear infinite;
}
@keyframes girar { to { transform: rotate(360deg); } }
.pliego { display: flex; position: relative; }
.pliego .hoja + .hoja::before {
  content: ""; position: absolute; inset: 0 auto 0 0; width: 26px; z-index: 1; pointer-events: none;
  background: linear-gradient(90deg, rgba(0, 0, 0, .16), transparent);
}
.pliego .hoja:first-child:not(:only-child)::before {
  content: ""; position: absolute; inset: 0 0 0 auto; width: 26px; z-index: 1; pointer-events: none;
  background: linear-gradient(270deg, rgba(0, 0, 0, .12), transparent);
}

/* La hoja que da vuelta (modo libro abierto) */
.vuelta { position: absolute; top: 0; height: 100%; transform-style: preserve-3d; z-index: 3; transition: transform .62s cubic-bezier(.45, .05, .25, 1); }
.vuelta .cara { position: absolute; inset: 0; backface-visibility: hidden; -webkit-backface-visibility: hidden; background: var(--papel); }
.vuelta .cara canvas { display: block; width: 100%; height: 100%; }
.vuelta .atras { transform: rotateY(180deg); }
.vuelta .cara::after { content: ""; position: absolute; inset: 0; pointer-events: none; opacity: 0; transition: opacity .62s; }
.vuelta.girando .cara::after { opacity: 1; }
.vuelta.hacia-adelante { transform-origin: left center; }
.vuelta.hacia-adelante .frente::after { background: linear-gradient(270deg, rgba(0,0,0,.25), transparent 60%); }
.vuelta.hacia-atras { transform-origin: right center; }
.vuelta.hacia-atras .frente::after { background: linear-gradient(90deg, rgba(0,0,0,.25), transparent 60%); }

/* Una página (celular): se desliza */
.deslizar { transition: transform .32s cubic-bezier(.3, .7, .3, 1), opacity .32s; }

.lado {
  position: absolute; top: 50%; transform: translateY(-50%); z-index: 5; width: 48px; height: 72px; border: 0;
  background: rgba(25, 24, 23, .55); color: var(--papel); display: grid; place-items: center; border-radius: 6px;
}
.lado:hover { background: rgba(25, 24, 23, .85); }
.lado:disabled { opacity: 0; pointer-events: none; }
.lado-izq { left: max(8px, env(safe-area-inset-left)); }
.lado-der { right: max(8px, env(safe-area-inset-right)); }
@media (hover: none) { .lado { display: none; } }

.zoom { position: absolute; inset: 0; overflow: auto; z-index: 4; background: var(--mesa); cursor: grab; touch-action: pan-x pan-y; }
.zoom.arrastrando { cursor: grabbing; }
.zoom canvas { display: block; margin: 0 auto; background: var(--papel); }

.barra-baja { border-top: 1px solid var(--mesa-borde); padding-bottom: max(10px, env(safe-area-inset-bottom)); }
#regla { flex: 1; accent-color: var(--vino); min-width: 0; height: 32px; }
.ir { display: flex; align-items: center; gap: 8px; flex: none; font-size: .85rem; color: var(--gris-claro); }
.ir input {
  width: 4.8em; padding: 8px 10px; text-align: center; font-size: .9rem; background: transparent; color: var(--papel);
  border: 1px solid var(--mesa-borde);
}
.aviso {
  position: fixed; left: 50%; bottom: 76px; transform: translateX(-50%); margin: 0; z-index: 10; max-width: calc(100% - 32px);
  background: var(--papel); color: var(--tinta); padding: 12px 18px; font-size: .9rem; box-shadow: 0 16px 40px -16px rgba(0,0,0,.6);
}

@media (prefers-reduced-motion: reduce) {
  .vuelta, .deslizar, .vuelta .cara::after { transition-duration: 1ms; }
}
@media print { body { display: none !important; } }