:root {
  --paper: #efe6d4;
  --paper-deep: #e5d9c2;
  --ink: #1c1714;
  --muted: #5c534a;
  --line: rgba(28, 23, 20, 0.18);
  --cinnabar: #8c2b22;
  --cinnabar-deep: #6d1f19;
  --cover: #7a241c;
  --stitch: #f4e7d2;
  --moss: #1e3a32;
  --card: #f7f1e4;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Songti SC", "Noto Serif SC", "Source Han Serif SC", "STSong", "SimSun", "PMingLiU", serif;
  --sans: "Avenir Next", "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --measure: 40rem;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    radial-gradient(ellipse at 0% 0%, rgba(140, 43, 34, 0.06), transparent 46%),
    radial-gradient(ellipse at 100% 80%, rgba(30, 58, 50, 0.06), transparent 42%);
  font-family: var(--serif);
  font-size: 1.125rem;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.18;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.8' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

a { color: inherit; }

a:hover { color: var(--cinnabar-deep); }

:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  background: var(--ink);
  color: var(--paper);
  padding: 0.4rem 0.7rem;
  z-index: 20;
}

.skip:focus { top: 1rem; }

.book {
  display: grid;
  grid-template-columns: 4.75rem minmax(0, 1fr);
  min-height: 100vh;
}

.spine {
  position: sticky;
  top: 0;
  height: 100vh;
  background: var(--cover);
  color: var(--stitch);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 1.35rem 0 1.1rem;
  z-index: 4;
}

.spine::before,
.spine::after {
  content: "";
  position: absolute;
  top: 0.9rem;
  bottom: 0.9rem;
  width: 1px;
  background-image: repeating-linear-gradient(
    to bottom,
    var(--stitch) 0 7px,
    transparent 7px 16px
  );
  opacity: 0.85;
}

.spine::before { left: 0.7rem; }
.spine::after { right: 0.7rem; }

.spine a {
  color: inherit;
  text-decoration: none;
}

.spine-mark {
  writing-mode: vertical-rl;
  letter-spacing: 0.42em;
  font-size: 1.05rem;
  font-weight: 600;
}

.spine-domain {
  writing-mode: vertical-rl;
  letter-spacing: 0.14em;
  font-family: var(--sans);
  font-size: 0.68rem;
  opacity: 0.78;
}

.page {
  position: relative;
  width: min(1120px, calc(100% - 8vw));
  margin: 0 auto;
  padding: 2.6rem 0 3.5rem;
}

.hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(230px, 0.72fr);
  gap: 2.5rem 3rem;
  align-items: end;
  padding-bottom: 2.2rem;
  border-bottom: 1px solid var(--ink);
}

.ghost {
  position: absolute;
  right: 32%;
  top: -0.8rem;
  font-size: clamp(8rem, 18vw, 14rem);
  line-height: 0.75;
  color: rgba(28, 23, 20, 0.055);
  pointer-events: none;
  user-select: none;
}

.kicker {
  margin: 0 0 0.8rem;
  font-family: var(--sans);
  font-size: 0.75rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--cinnabar);
}

h1 {
  margin: 0;
  font-size: clamp(3.1rem, 7vw, 5.8rem);
  font-weight: 600;
  line-height: 1.02;
  letter-spacing: 0.045em;
}

h1 span { display: block; }

.motto-en {
  margin: 1rem 0 0;
  font-family: var(--sans);
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.lede {
  max-width: var(--measure);
  margin: 1.35rem 0 0;
  font-size: 1.2rem;
}

.card {
  position: relative;
  z-index: 1;
  background: var(--card);
  border: 1px solid var(--ink);
  box-shadow: 6px 6px 0 rgba(28, 23, 20, 0.08);
  padding: 1.15rem 1.25rem 1.35rem;
}

.card-label {
  margin: 0 0 0.7rem;
  font-family: var(--sans);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cinnabar);
}

.card dl {
  margin: 0;
  display: grid;
  grid-template-columns: 4.2rem 1fr;
  gap: 0.45rem 0.6rem;
  padding-right: 3.2rem;
  font-size: 0.98rem;
}

.card dt {
  margin: 0;
  color: var(--muted);
}

.card dd { margin: 0; }

.seal {
  position: absolute;
  right: 0.85rem;
  bottom: 0.75rem;
  width: 3.1rem;
  height: 3.1rem;
  border: 2px solid var(--cinnabar);
  color: var(--cinnabar);
  display: grid;
  place-items: center;
  font-size: 1.35rem;
  letter-spacing: 0.08em;
  transform: rotate(-8deg);
  opacity: 0.9;
  background: rgba(247, 241, 228, 0.6);
}

.toc {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.4rem;
  margin: 1.3rem 0 0;
  padding: 0;
  list-style: none;
  font-family: var(--sans);
  font-size: 0.92rem;
}

.toc a { text-decoration: none; border-bottom: 1px solid var(--line); }

.section {
  padding: 2.6rem 0 0.2rem;
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: baseline;
  border-bottom: 1px solid var(--line);
  margin-bottom: 1.2rem;
}

h2 {
  margin: 0;
  font-size: 1.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.section-index {
  font-family: var(--sans);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.prose {
  max-width: var(--measure);
  margin: 0;
}

.prose strong { font-weight: 650; }

.seqs { display: flex; flex-direction: column; }

.seq {
  border-bottom: 1px solid var(--line);
}

.seq summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: 4.2rem minmax(6rem, 9rem) 1fr auto;
  gap: 0.8rem;
  align-items: baseline;
  padding: 1.05rem 0.2rem;
}

.seq summary::-webkit-details-marker { display: none; }

.seq summary:hover .seq-name { color: var(--cinnabar-deep); }

.seq-num {
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.08em;
  color: var(--cinnabar);
}

.seq-name {
  font-size: 1.35rem;
  letter-spacing: 0.08em;
}

.seq-brief { color: var(--muted); }

.seq-state {
  font-family: var(--sans);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--moss);
}

.seq-body {
  max-width: var(--measure);
  margin: 0 0 1.15rem 4.2rem;
  color: var(--ink);
}

.rules {
  list-style: none;
  margin: 0;
  padding: 0;
  max-width: 46rem;
}

.rules li {
  display: grid;
  grid-template-columns: 3rem 1fr;
  gap: 0.6rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--line);
}

.rules span {
  color: var(--cinnabar);
  font-variant-numeric: tabular-nums;
}

.note {
  margin-top: 1.4rem;
  max-width: var(--measure);
  padding-left: 0.9rem;
  border-left: 3px solid var(--cinnabar);
  color: var(--muted);
}

.colophon {
  margin-top: 4.2rem;
  padding: 1.6rem 1rem 0.4rem;
  border-top: 1px solid var(--ink);
  text-align: center;
}

.colophon-name {
  margin: 0;
  font-size: 1.35rem;
  letter-spacing: 0.28em;
}

.colophon-meta {
  margin: 0.35rem 0 0.9rem;
  color: var(--muted);
  font-size: 0.95rem;
}

.beian-no {
  margin: 0.2rem 0 0.15rem;
  font-size: 1rem;
}

.beian-no a {
  color: var(--ink);
  text-decoration-thickness: 1px;
  text-decoration-color: var(--cinnabar);
  text-underline-offset: 0.22em;
}

.beian-miit {
  margin: 0.15rem 0 0;
  font-family: var(--sans);
  font-size: 0.84rem;
}

.beian-miit a { color: var(--cinnabar-deep); }

.copy {
  margin: 1rem 0 0;
  font-family: var(--sans);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.miss {
  min-height: 46vh;
  display: grid;
  align-content: end;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--ink);
}

.miss h1 { font-size: clamp(2.6rem, 6vw, 4.4rem); }

.back {
  display: inline-block;
  margin-top: 1rem;
  font-family: var(--sans);
  letter-spacing: 0.08em;
}

@media (max-width: 860px) {
  .book { grid-template-columns: 1fr; }
  .spine {
    height: auto;
    flex-direction: row;
    padding: 0.85rem 1.1rem;
  }
  .spine::before,
  .spine::after { display: none; }
  .spine-mark,
  .spine-domain {
    writing-mode: horizontal-tb;
    letter-spacing: 0.22em;
  }
  .spine-domain { letter-spacing: 0.08em; }
  .page { width: min(1120px, calc(100% - 2rem)); padding-top: 1.6rem; }
  .hero { grid-template-columns: 1fr; gap: 1.6rem; }
  .ghost { display: none; }
  .seq summary {
    grid-template-columns: 2.6rem 1fr;
    grid-template-areas:
      "num name"
      "num brief"
      "num state";
  }
  .seq-num { grid-area: num; }
  .seq-name { grid-area: name; }
  .seq-brief { grid-area: brief; }
  .seq-state { grid-area: state; }
  .seq-body { margin-left: 0; }
  h1 { letter-spacing: 0.02em; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}