/* Sion Book — un libro abierto sobre una web moderna */

:root {
  --desk: #060b1f;
  --leather: #0a1f6b;
  --leather-2: #050f3a;
  --gold: #00a3e0;
  --gold-soft: #7fd8ff;
  --paper: #f6f8fd;
  --ink: #262a35;
  --muted: #596177;
  --accent: #0a3df0;
  --accent-2: #001fb5;
  --rule: #cfd8ec;
  --serif: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Palatino, "URW Palladio L", Georgia, "Times New Roman", serif;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--ink);
  background:
    radial-gradient(1200px 700px at 50% -10%, #0f1a45 0%, transparent 70%),
    var(--desk);
}

img { max-width: 100%; height: auto; }
a { color: var(--accent); text-underline-offset: .18em; text-decoration-thickness: .06em; }
a:hover { color: var(--accent-2); }
:focus-visible { outline: 2px solid var(--gold); outline-offset: 3px; border-radius: 2px; }
main:focus { outline: none; }

.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: -999px; top: 8px; }
.skip:focus { left: 12px; z-index: 100; background: #fff; color: #000; padding: .5rem 1rem; border-radius: 4px; }

/* ---------- El libro ---------- */

.wrap { max-width: 1800px; margin: 0 auto; padding: clamp(8px, 1.4vw, 24px); }

.book {
  position: relative;
  padding: clamp(8px, 1.2vw, 16px);
  border-radius: 14px;
  background: linear-gradient(160deg, #1a36a8 0%, var(--leather) 45%, var(--leather-2) 100%);
  box-shadow: 0 50px 90px -30px #000c, 0 18px 30px -12px #0008, inset 0 0 0 1px #7fd8ff22, inset 0 2px 0 #ffffff14;
}
.book::before {
  content: ""; position: absolute; inset: 5px; border: 1px solid #4fc3ff55; border-radius: 10px; pointer-events: none;
}

.spread {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  min-height: 70vh;
  perspective: 2800px;
  border-radius: 4px;
  box-shadow:
    -1px 1px 0 #ffffff,
    1px 1px 0 #ffffff,
    0 1px 0 #ffffff,
    -2px 2px 0 #a9b5d4,
    2px 2px 0 #a9b5d4,
    0 2px 0 #a9b5d4,
    -3px 3px 0 #ffffff,
    3px 3px 0 #ffffff,
    0 3px 0 #ffffff,
    -4px 4px 0 #6f7cab,
    4px 4px 0 #6f7cab,
    0 4px 0 #6f7cab,
    0 14px 22px -6px #0009;
}

/* El recorte solo se usa en móvil */
.clip { display: contents; }
.ribbon-btn, .lang.lang--mini { display: none; }

/* Papel */
.paper {
  position: relative;
  background:
    linear-gradient(180deg, #ffffff 0, transparent 120px),
    repeating-linear-gradient(0deg, #0000 0 29px, #00000005 29px 30px),
    var(--paper);
}
.paper--left, .paper--right { display: flex; flex-direction: column; }
.paper--left { border-radius: 4px 0 0 4px; }
.paper--right { border-radius: 0 4px 4px 0; }

/* Sombra del lomo en el centro */
.paper--left::after, .paper--right::before {
  content: ""; position: absolute; top: 0; bottom: 0; width: clamp(28px, 4vw, 64px); pointer-events: none; z-index: 1;
}
.paper--left::after { right: 0; background: linear-gradient(90deg, transparent, #1a265033 70%, #0d184055); }
.paper--right::before { left: 0; background: linear-gradient(270deg, transparent, #1a265026 70%, #0d18404d); }

/* Marcapáginas: en Inicio decora; en el resto es un enlace al índice */
.ribbon {
  position: absolute; top: 0; right: clamp(18px, 4vw, 48px); z-index: 2; width: 22px; height: 64px;
  background: linear-gradient(180deg, #00c8ff, #0030ff);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 50% 82%, 0 100%);
  transition: height .25s ease, filter .25s ease;
}
a.ribbon:hover, a.ribbon:focus-visible { height: 74px; filter: brightness(1.12); }

.page-inner {
  position: relative; flex: 1; display: flex; flex-direction: column;
  padding: clamp(22px, 4vw, 56px) clamp(22px, 4vw, 56px) clamp(22px, 3vw, 40px);
}
.paper--right .page-inner { padding-left: clamp(30px, 5vw, 72px); }
.paper--left .page-inner { padding-right: clamp(30px, 5vw, 72px); gap: 1.8rem; }

#page-left > .page-inner, #page-right > .page-inner { animation: settle .5s ease both; }
@keyframes settle { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

.content { flex: 1 0 auto; }

/* ---------- Tipografía ---------- */

h1, h2, h3 { font-weight: 600; line-height: 1.15; margin: 0 0 .5em; color: #1b2030; }
h1 { font-size: clamp(2rem, 4.2vw, 3.1rem); }
h2 { font-size: clamp(1.35rem, 2.2vw, 1.7rem); }
h3 { font-size: 1.1rem; }
p { margin: 0 0 1em; }
.lead { font-size: 1.2rem; color: #3a4155; }
.eyebrow { font-variant: small-caps; letter-spacing: .14em; color: var(--accent); font-size: .98rem; margin: 0 0 .6rem; }
.subtitle { font-style: italic; color: var(--muted); font-size: 1.2rem; margin: -.2rem 0 .6rem; }
.byline { color: var(--muted); margin-bottom: 1.2rem; }
.dropcap::first-letter { float: left; font-size: 3.7em; line-height: .85; padding: .08em .1em 0 0; color: var(--accent); }

.rule { display: flex; align-items: center; gap: .8rem; margin: 1.8rem 0; color: var(--gold); }
.rule::before, .rule::after { content: ""; height: 1px; flex: 1; background: linear-gradient(90deg, transparent, var(--gold-soft)); }
.rule::after { transform: scaleX(-1); }
.rule i { width: 7px; height: 7px; background: currentColor; transform: rotate(45deg); }

.breadcrumb { font-size: .95rem; margin: 0 0 1rem; color: var(--muted); }
.breadcrumb a { color: var(--muted); }

/* ---------- Página izquierda: índice ---------- */

/* Cabecera de la hoja izquierda: marca + selector de idioma */
.head { display: flex; justify-content: space-between; align-items: flex-start; gap: 1rem; }
.lang {
  display: inline-flex; flex: none; margin-top: .35rem; padding: 3px; gap: 2px;
  border: 1px solid var(--rule); border-radius: 999px; background: #ffffffcc;
  box-shadow: 0 1px 0 #fff inset, 0 6px 14px -10px #0a1f6b99;
  font-size: .78rem; letter-spacing: .14em; line-height: 1; font-variant: normal;
}
.lang a, .lang .lang-on { display: block; padding: .42rem .8rem .42rem .9rem; border-radius: 999px; text-decoration: none; }
.lang a { color: var(--muted); transition: color .2s ease, background .2s ease; }
.lang a:hover { color: var(--accent); background: #0a3df01a; }
.lang .lang-on { color: #fff; background: linear-gradient(180deg, var(--accent), var(--accent-2)); box-shadow: 0 1px 0 #fff3 inset; }

.brand { display: flex; flex-direction: column; align-items: flex-start; gap: .1rem; text-decoration: none; color: var(--ink); }
.brand:hover { color: var(--ink); }
.brand img { width: clamp(150px, 18vw, 210px); height: auto; display: block; }
.brand-sub { font-variant: small-caps; letter-spacing: .3em; color: var(--muted); font-size: .85rem; }

.toc-label { font-variant: small-caps; letter-spacing: .2em; color: var(--muted); font-size: .9rem; margin: 0 0 .4rem; border-bottom: 1px solid var(--rule); padding-bottom: .4rem; }
.toc { list-style: none; margin: 0; padding: 0; }
.toc a { display: flex; align-items: baseline; gap: .6rem; padding: .36rem 0; text-decoration: none; color: var(--ink); }
.toc-num { width: 2.2em; color: var(--gold); font-variant: small-caps; font-size: .95rem; }
.toc-dots { flex: 1; border-bottom: 1px dotted #8a96b5; transform: translateY(-.25em); min-width: 1rem; }
.toc-page { font-variant-numeric: oldstyle-nums; color: var(--muted); }
.toc a:hover .toc-title { color: var(--accent); }
.toc [aria-current="page"] .toc-title { color: var(--accent); font-style: italic; }
.toc [aria-current="true"] .toc-title { color: var(--accent); }
.toc--books { max-height: min(62vh, 560px); overflow: auto; padding-right: .4rem; scrollbar-width: thin; }
.toc--books a { padding: .45rem 0; }
.back-index { align-self: flex-start; font-variant: small-caps; letter-spacing: .14em; font-size: .92rem; color: var(--muted); text-decoration: none; margin: -.6rem 0 0; }
.back-index:hover { color: var(--accent); }

.left-extra { flex: 1; display: flex; align-items: center; justify-content: center; min-height: 0; }
.left-extra .cover { width: min(340px, 82%); }
.ornament { width: min(180px, 60%); color: var(--gold); opacity: .8; }
.left-quote { text-align: center; color: var(--muted); font-style: italic; margin-top: 1rem; }

.left-footer { font-size: .85rem; color: var(--muted); line-height: 1.5; border-top: 1px solid var(--rule); padding-top: 1rem; }
.left-footer p { margin: 0 0 .4rem; }

/* ---------- Portadas ---------- */

.cover {
  --c: #0a2a8a;
  position: relative; display: block; aspect-ratio: 2 / 3; overflow: hidden; container-type: inline-size;
  border-radius: 3px 6px 6px 3px; color: #f2f7ff;
  background: var(--c);
  background: linear-gradient(135deg, color-mix(in srgb, var(--c) 82%, #fff) 0, var(--c) 45%, color-mix(in srgb, var(--c) 70%, #000) 100%);
  box-shadow: 0 14px 24px -10px #000a, 0 2px 4px #0005, inset 0 0 0 1px #ffffff1c;
}
.cover::before { content: ""; position: absolute; inset: 0 auto 0 0; width: 7%; background: linear-gradient(90deg, #0005, #fff2 60%, #0000); z-index: 2; }
.cover img { width: 100%; height: 100%; object-fit: cover; display: block; }
.cover-frame {
  position: absolute; inset: 6%; border: 1px solid #bfe9ff88; display: flex; flex-direction: column;
  justify-content: space-between; align-items: center; text-align: center; padding: 12% 8% 9%;
}
.cover-title { font-size: 9.5cqw; line-height: 1.1; font-weight: 600; }
.cover-sub { font-size: 5cqw; font-style: italic; opacity: .9; margin-top: 4%; }
.cover-author { font-size: 5cqw; letter-spacing: .16em; text-transform: uppercase; }
.cover-mark { width: 12cqw; color: #bfe9ff; }

/* ---------- Tarjetas y rejilla ---------- */

.chips { gap: .5rem; flex-wrap: wrap; margin: 0 0 1.4rem; padding: 0; }
.js-only { display: none; }
html.js .js-only { display: flex; }
.chip {
  font: inherit; font-size: .95rem; padding: .3rem .85rem; border: 1px solid var(--rule); background: #ffffff;
  border-radius: 999px; color: var(--ink); cursor: pointer;
}
.chip:hover { border-color: var(--accent); }
.chip[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: #fff; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 1.6rem 1.3rem; list-style: none; padding: 0; margin: 0 0 1rem; }
.card { position: relative; }
.card[hidden] { display: none; }
.card .cover { transition: transform .3s ease, box-shadow .3s ease; }
.card:hover .cover { transform: translateY(-4px) rotate(-.6deg); box-shadow: 0 22px 30px -12px #000b, 0 2px 4px #0005, inset 0 0 0 1px #ffffff1c; }
.card-cat { font-variant: small-caps; letter-spacing: .1em; color: var(--accent); font-size: .85rem; margin: .7rem 0 0; }
.card-title { font-size: 1.05rem; margin: .1rem 0 .1rem; line-height: 1.25; }
.card-title a { color: inherit; text-decoration: none; }
.card-title a::after { content: ""; position: absolute; inset: 0; }
.card--soon .card-title { margin-top: .1rem; }
.card--soon:hover .cover { transform: none; box-shadow: 0 14px 24px -10px #000a, 0 2px 4px #0005, inset 0 0 0 1px #ffffff1c; }
.card--soon .cover { opacity: .92; }
.card-sub { font-style: italic; color: var(--muted); font-size: .9rem; margin: 0 0 .15rem; line-height: 1.3; }
.card-note { color: var(--muted); font-size: .88rem; line-height: 1.35; margin: 0 0 .3rem; }
.card-author { color: var(--muted); font-size: .92rem; margin: 0; }

.formats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 1rem; list-style: none; padding: 0; margin: 0 0 1rem; }
.formats li { padding: 1rem; border: 1px solid var(--rule); border-radius: 4px; background: #ffffff88; }
.formats p { margin: 0; font-size: .95rem; color: var(--muted); }

/* ---------- Ficha de libro ---------- */

.meta { display: grid; grid-template-columns: auto 1fr; gap: .25rem 1.2rem; margin: 1.2rem 0; padding: 1rem 0; border-block: 1px solid var(--rule); font-size: .97rem; }
.meta dt { color: var(--muted); font-variant: small-caps; letter-spacing: .08em; }
.meta dd { margin: 0; }
.prose p { text-align: justify; hyphens: auto; }

.buy { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: .8rem; margin: 1rem 0 .6rem; }
.btn {
  position: relative; display: flex; flex-direction: column; align-items: flex-start; gap: .05rem;
  padding: .7rem 2.6rem .7rem 1.1rem; border-radius: 4px; text-decoration: none; color: #ffffff;
  background: linear-gradient(180deg, var(--accent), var(--accent-2)); border: 1px solid #001a8a;
  box-shadow: 0 1px 0 #fff3 inset, 0 6px 14px -8px #000a; transition: transform .2s ease, box-shadow .2s ease;
}
.btn::after { content: "\2197"; position: absolute; right: 1rem; top: 50%; transform: translateY(-50%); font-size: 1.1rem; }
.btn:hover { transform: translateY(-2px); color: #fff; box-shadow: 0 1px 0 #fff3 inset, 0 10px 18px -8px #000b; }
.btn-kicker { font-size: .76rem; letter-spacing: .12em; text-transform: uppercase; opacity: .85; }
.btn-label { font-size: 1.12rem; font-weight: 600; }
.btn.is-disabled { background: #e3e8f4; color: #6b7488; border-color: #c8d1e6; box-shadow: none; cursor: default; }
.btn.is-disabled::after { content: ""; }
.fineprint { font-size: .88rem; color: var(--muted); }

.cta { display: inline-block; margin-top: .4rem; }
.link-arrow { font-weight: 600; }

/* ---------- Folio (pie de página del libro) ---------- */

.folio {
  display: grid; grid-template-columns: 1fr auto 1fr; gap: 1rem; align-items: center;
  margin-top: 2.4rem; padding-top: 1rem; border-top: 1px solid var(--rule); font-size: .95rem; color: var(--muted);
}
.folio a { display: block; max-width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; text-decoration: none; color: var(--muted); }
.folio a:hover { color: var(--accent); }
.folio .next { text-align: right; }
.folio-num { font-variant-numeric: oldstyle-nums; letter-spacing: .1em; }
.mobile-footer { display: none; }

/* ---------- Hoja que se pasa: la esquina superior derecha se levanta ---------- */

.curl { position: absolute; inset: 0; z-index: 30; overflow: hidden; pointer-events: none; }
.curl-layer { position: absolute; inset: 0; visibility: hidden; }
.curl-page { position: absolute; top: 0; overflow: hidden; }
.curl-page .page-inner { animation: none; }
.curl-strip { position: absolute; left: 0; top: 0; transform-origin: 0 0; width: 90px; }
.curl-under .curl-strip { background: linear-gradient(90deg, #0a1440b0, #0a144000); }
.curl-front .curl-strip { width: 70px; background: linear-gradient(90deg, #0a144070, #0a144000); }
.curl-flap .curl-strip { width: 120px; background: linear-gradient(90deg, #0a144060, #ffffff4d 38%, #0a14400f); }

/* ---------- Pantallas anchas / estrechas ---------- */

.only-narrow { display: none; }

@media (min-width: 900px) {
  .book { padding: clamp(12px, 1.2vw, 18px) clamp(22px, 2.2vw, 34px) clamp(24px, 2.2vw, 34px); }
  .spread {
    grid-template-columns: 1fr 1fr; min-height: min(84vh, 980px);
    box-shadow:
    -1px 1px 0 #ffffff,
    1px 1px 0 #ffffff,
    0 1px 0 #ffffff,
    -2px 2px 0 #a9b5d4,
    2px 2px 0 #a9b5d4,
    0 2px 0 #a9b5d4,
    -3px 3px 0 #ffffff,
    3px 3px 0 #ffffff,
    0 3px 0 #ffffff,
    -4px 4px 0 #a9b5d4,
    4px 4px 0 #a9b5d4,
    0 4px 0 #a9b5d4,
    -5px 5px 0 #ffffff,
    5px 5px 0 #ffffff,
    0 5px 0 #ffffff,
    -6px 6px 0 #a9b5d4,
    6px 6px 0 #a9b5d4,
    0 6px 0 #a9b5d4,
    -7px 7px 0 #ffffff,
    7px 7px 0 #ffffff,
    0 7px 0 #ffffff,
    -8px 8px 0 #a9b5d4,
    8px 8px 0 #a9b5d4,
    0 8px 0 #a9b5d4,
    -9px 9px 0 #ffffff,
    9px 9px 0 #ffffff,
    0 9px 0 #ffffff,
    -10px 10px 0 #a9b5d4,
    10px 10px 0 #a9b5d4,
    0 10px 0 #a9b5d4,
    -11px 11px 0 #ffffff,
    11px 11px 0 #ffffff,
    0 11px 0 #ffffff,
    -12px 12px 0 #6f7cab,
    12px 12px 0 #6f7cab,
    0 12px 0 #6f7cab,
    0 22px 30px -8px #000b;
  }
}

@media (max-width: 899.98px) {
  .only-narrow { display: block; }
  .page-inner, .paper--right .page-inner, .paper--left .page-inner { padding: 20px 20px 26px; }
  .paper--right .content > :is(.eyebrow, .breadcrumb, h1) { padding-right: 34px; }
  .paper--right .content > .cover { margin-top: .5rem; }
  .mobile-footer { display: block; font-size: .85rem; color: var(--muted); margin-top: 1.4rem; line-height: 1.5; }
  .prose p { text-align: left; }
  .cover.only-narrow { width: min(240px, 70%); margin: 0 auto 1.4rem; }
  .head { align-items: center; }

  /* Sin JavaScript: hojas apiladas, índice compacto arriba */
  html:not(.js) .spread { overflow: hidden; }
  html:not(.js) .only-wide { display: none; }
  html:not(.js) .paper--left { border-radius: 4px 4px 0 0; }
  html:not(.js) .paper--right { border-radius: 0 0 4px 4px; }
  html:not(.js) .paper--left::after, html:not(.js) .paper--right::before { display: none; }
  html:not(.js) .paper--left .page-inner { gap: .9rem; padding-bottom: 10px; }
  html:not(.js) .brand { flex-direction: row; align-items: center; gap: .7rem; flex-wrap: wrap; }
  html:not(.js) .brand img { width: 120px; }
  html:not(.js) :is(.toc-label, .toc-num, .toc-dots, .toc-page, .toc--sub, .left-extra, .left-footer) { display: none; }
  html:not(.js) .toc { display: flex; flex-wrap: wrap; gap: .1rem 1.2rem; }
  html:not(.js) .toc a { padding: .25rem 0; }
  html:not(.js) .toc.toc--sub { display: none; }

  /* Con JavaScript: un libro abierto del que solo se ve la hoja derecha.
     La izquierda (el índice) asoma por el borde; se abre tocando el borde, la cinta o deslizando. */
  html.js { --peek: clamp(18px, 6vw, 30px); }
  html.js .clip { display: block; overflow: hidden; border-radius: 4px; padding-bottom: 6px; }
  html.js .spread {
    grid-template-columns: 1fr 1fr; width: calc(200% - 2 * var(--peek)); min-height: 78vh; border-radius: 0;
    transform: translateX(calc(-50% + var(--peek)));
    transition: transform .5s cubic-bezier(.3, .1, .2, 1);
    box-shadow: 0 1px 0 #fff, 0 2px 0 #a9b5d4, 0 3px 0 #fff, 0 4px 0 #6f7cab;
  }
  html.js .spread.show-index { transform: translateX(0); }
  html.js .paper--left { border-radius: 4px 0 0 4px; }
  html.js .paper--right { border-radius: 0 4px 4px 0; }
  /* Lomo: el borde visible de la hoja izquierda se curva hacia el centro, con cantos de hojas */
  html.js .paper--left::after {
    display: block; width: var(--peek); right: 0;
    background: linear-gradient(90deg, transparent, #1a265044 70%, #0d184077), repeating-linear-gradient(90deg, #0000 0 3px, #8a96b566 3px 4px);
  }
  html.js .paper--right::before { display: block; width: 16px; left: 0; }
  html.js .paper--left .page-inner { padding: 22px 36px 24px 22px; gap: 1.4rem; }
  html.js .paper--right .page-inner { padding: 20px 20px 26px 28px; }
  html.js .head { align-items: flex-start; }
  html.js .brand img { width: 140px; }
  html.js .only-wide { display: block; }
  /* La cinta pasa a ser un botón: abre el índice */
  html.js .ribbon { display: none; }
  html.js .ribbon-btn {
    display: block; position: absolute; top: 0; right: clamp(14px, 5vw, 22px); z-index: 3; width: 26px; height: 72px; padding: 0; border: 0; cursor: pointer;
    background: linear-gradient(180deg, #00c8ff, #0030ff); clip-path: polygon(0 0, 100% 0, 100% 100%, 50% 82%, 0 100%);
  }
  html.js .ribbon-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
  html.js .lang--mini { display: inline-flex; align-self: flex-start; margin: 0 0 1rem; }
  html.js .lang--mini a, html.js .lang--mini .lang-on { padding: .34rem .7rem .34rem .8rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}