:root {
  --paper: #e7dfd1;
  --paper-2: #f4efe6;
  --cream: #f7f3eb;
  --ink: #1b1814;
  --ink-soft: #5c534b;
  --line: rgba(27, 24, 20, 0.16);
  --lacquer: #8d2b28;
  --night: #171512;
  --night-2: #241f1b;
  --sand: #d9cebc;
  --header: 74px;
  --serif: "Songti SC", "Noto Serif CJK SC", "Noto Serif SC", "Source Han Serif SC", "STSong", "PMingLiU", "AR PL UMing CN", Palatino, "Palatino Linotype", serif;
  --sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
  --num: "Avenir Next", "DIN Alternate", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  color-scheme: light;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}
body.nav-lock { overflow: hidden; }
img, svg { max-width: 100%; }
button, input { font: inherit; color: inherit; }
::selection { background: var(--lacquer); color: var(--cream); }

a { color: inherit; }
:focus-visible {
  outline: 2px solid var(--lacquer);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: 16px;
  top: -48px;
  z-index: 80;
  background: var(--ink);
  color: var(--cream);
  padding: 8px 12px;
  text-decoration: none;
}
.skip:focus { top: 12px; }

.mast {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: 24px;
  min-height: var(--header);
  padding: 10px 28px 0;
  background: var(--paper);
  border-bottom: 1px solid transparent;
}
.mast::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 5px;
  background: var(--ink);
}
.mast.is-stuck {
  border-bottom-color: var(--line);
  box-shadow: 0 10px 30px rgba(27, 24, 20, 0.05);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: inherit;
  margin-right: auto;
}
.brand-seal {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  border: 1.5px solid currentColor;
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.05; }
.brand-text strong { font-family: var(--serif); font-size: 20px; font-weight: 650; letter-spacing: 0.08em; }
.brand-text small { font-size: 10px; letter-spacing: 0.22em; color: var(--ink-soft); }

.nav { display: flex; align-items: center; gap: 26px; }
.nav a {
  text-decoration: none;
  font-size: 15px;
  padding: 8px 0;
}
.nav a[aria-current="page"] { box-shadow: inset 0 -1.5px 0 var(--lacquer); }
.nav-shelf { display: inline-flex; align-items: center; }
.nav-shelf span,
[data-shelf-count] {
  display: inline-grid;
  place-items: center;
  min-width: 1.5em;
  margin-left: 6px;
  padding: 0 6px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--cream);
  font-family: var(--num);
  font-size: 12px;
  font-style: normal;
  line-height: 1.6;
}
.nav-btn {
  display: none;
  appearance: none;
  background: transparent;
  border: 1px solid var(--ink);
  border-radius: 999px;
  padding: 8px 14px;
  cursor: pointer;
}

.wrap { width: min(1120px, calc(100% - 48px)); margin: 0 auto; }
.kicker {
  margin: 0;
  color: var(--lacquer);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}
h1, h2, h3 { font-family: var(--serif); font-weight: 650; line-height: 1.2; }
h1 { margin: 12px 0 0; font-size: clamp(36px, 5vw, 68px); letter-spacing: -0.02em; }
h2 { margin: 0; font-size: clamp(28px, 3vw, 42px); }
h3 { margin: 0; font-size: 22px; }
.lede { max-width: 38em; font-size: 18px; line-height: 1.8; color: var(--ink-soft); }
.fine { color: var(--ink-soft); font-size: 13px; line-height: 1.7; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--cream);
  text-decoration: none;
  border: 1px solid var(--ink);
}
.btn-ghost { background: transparent; color: var(--ink); }
.btn:hover { background: var(--lacquer); border-color: var(--lacquer); color: var(--cream); }

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(320px, 0.88fr);
  min-height: calc(100svh - var(--header));
  border-bottom: 1px solid var(--line);
}
.hero-copy {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 36px;
  padding: 64px 56px 40px;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.hero-stage {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 8px;
  padding: 32px 32px 28px;
  background:
    radial-gradient(1000px 280px at 80% 110%, rgba(141, 43, 40, 0.45), transparent 55%),
    var(--night);
  color: var(--cream);
  text-decoration: none;
  overflow: hidden;
}
.hero-stage:hover h2 { color: #f0c7b2; }
.stage-kicker { margin: 0; letter-spacing: 0.22em; font-size: 12px; color: #e4b2a4; }
.hero-stage .sil { width: 112%; margin: 18px 0 12px -4%; }
.stage-caption h2 { font-size: clamp(32px, 3vw, 48px); }
.stage-caption p { margin: 8px 0 14px; max-width: 28em; color: rgba(247, 243, 235, 0.78); }
.stage-caption span { letter-spacing: 0.14em; font-size: 13px; }

.section { padding: 84px 0; }
.sec-head {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px 24px;
  align-items: end;
  margin-bottom: 28px;
}
.sec-head .kicker { grid-column: 1; }
.sec-head h2 { grid-column: 1; }
.sec-head .more {
  grid-column: 2;
  grid-row: 1 / span 2;
  align-self: end;
  text-decoration: none;
  border-bottom: 1px solid var(--ink);
  padding-bottom: 2px;
}

.pillars {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line);
}
.pillars li {
  padding: 22px 22px 8px 0;
  border-bottom: 1px solid var(--line);
}
.pillars li + li { padding-left: 22px; box-shadow: inset 1px 0 0 var(--line); }
.pillars span {
  font-family: var(--num);
  color: var(--lacquer);
  letter-spacing: 0.14em;
  font-size: 13px;
}
.pillars h3 { margin: 14px 0 8px; }
.pillars p { margin: 0; color: var(--ink-soft); }

.spread { display: grid; grid-template-columns: 1.45fr 0.85fr; min-height: 540px; }
.spread a {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 460px;
  padding: 32px;
  text-decoration: none;
}
.spread-main { background: var(--night); color: var(--cream); }
.spread-side { background: #6f2e2b; color: #f7f3eb; }
.spread .kicker { color: #f0c7b2; }
.spread h2 { font-size: clamp(36px, 4vw, 60px); margin-top: 10px; }
.spread p { max-width: 28em; }
.spread .sil { margin-top: 24px; }

.toc { list-style: none; margin: 0; padding: 0; }
.toc a {
  display: grid;
  grid-template-columns: 64px minmax(140px, 0.9fr) minmax(90px, 0.5fr) minmax(180px, 1.4fr);
  gap: 12px 18px;
  align-items: baseline;
  padding: 20px 8px;
  border-top: 1px solid var(--line);
  text-decoration: none;
}
.toc li:last-child a { border-bottom: 1px solid var(--line); }
.toc a:hover { background: rgba(255, 252, 247, 0.45); }
.toc a:hover .toc-name { color: var(--lacquer); }
.toc-no { font-family: var(--num); color: var(--lacquer); letter-spacing: 0.14em; font-size: 13px; }
.toc-name { font-family: var(--serif); font-size: clamp(24px, 2vw, 32px); }
.toc-meta { color: var(--ink-soft); font-size: 14px; }
.toc-line { color: var(--ink-soft); }

.note-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.note-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-height: 240px;
  padding: 22px;
  background: var(--paper-2);
  border: 1px solid var(--line);
  text-decoration: none;
}
.note-card:hover { border-color: var(--ink); }
.note-card strong { font-family: var(--serif); font-size: 26px; font-weight: 650; line-height: 1.35; }
.note-card span { margin-top: auto; font-size: 13px; letter-spacing: 0.12em; }

.page-hero { padding: 54px 0 12px; }
.page-hero h1 { max-width: 12em; }
.page-hero .lede { margin-bottom: 0; }

.tools {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  margin: 28px 0 18px;
}
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  appearance: none;
  min-height: 40px;
  padding: 0 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: transparent;
  cursor: pointer;
}
.chip.is-on { background: var(--ink); color: var(--cream); border-color: var(--ink); }
.search {
  min-width: min(100%, 240px);
  min-height: 44px;
  padding: 8px 2px;
  border: none;
  border-bottom: 1px solid var(--ink);
  background: transparent;
  border-radius: 0;
}
.result-line { margin: 0 0 14px; color: var(--ink-soft); font-size: 14px; }

.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.car-card {
  position: relative;
  background: var(--paper-2);
  border: 1px solid var(--line);
  min-height: 320px;
}
.car-card:hover { border-color: var(--ink); }
.car-card-hit {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 22px 22px 16px;
  text-decoration: none;
}
.car-card h2 { font-size: 32px; margin: 10px 0 8px; padding-right: 88px; }
.car-card p { margin: 0; color: var(--ink-soft); }
.car-card .sil { margin-top: auto; padding-top: 18px; }
.save-mini {
  position: absolute;
  top: 16px;
  right: 16px;
  z-index: 1;
  min-height: 36px;
  padding: 0 12px;
  font-size: 13px;
}

.save-btn {
  appearance: none;
  min-height: 42px;
  padding: 0 16px;
  border-radius: 999px;
  border: 1px solid var(--ink);
  background: transparent;
  cursor: pointer;
}
.save-btn[aria-pressed="true"] {
  background: var(--lacquer);
  border-color: var(--lacquer);
  color: var(--cream);
}
.empty {
  padding: 48px 0 24px;
  color: var(--ink-soft);
}

.detail { padding-bottom: 28px; }
.crumb { margin: 0 0 18px; color: var(--ink-soft); font-size: 14px; }
.crumb a { color: inherit; }
.detail-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(280px, 0.95fr);
  gap: 36px;
  align-items: end;
  padding-bottom: 28px;
}
.detail-copy h1 { max-width: 9em; }
.detail-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.detail-art {
  background: var(--night);
  color: var(--cream);
  padding: 28px 20px 18px;
}
.detail-art .sil { width: 108%; margin-left: -4%; }
.facts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  margin: 8px 0 36px;
  background: var(--line);
  border: 1px solid var(--line);
}
.facts div { background: var(--paper-2); padding: 16px 18px; }
.facts span { display: block; color: var(--ink-soft); font-size: 12px; letter-spacing: 0.14em; }
.facts strong { display: block; margin-top: 6px; font-family: var(--serif); font-size: 22px; font-weight: 650; }

.prose { max-width: 68ch; }
.prose h2 { font-size: 30px; margin: 36px 0 10px; }
.prose p { margin: 0 0 16px; font-size: 17.5px; line-height: 1.9; }
.prose ul { margin: 0 0 16px; padding-left: 1.2em; }
.prose li { margin: 6px 0; }
.know {
  margin: 8px 0 0;
  padding: 8px 0 0;
  list-style: none;
}
.know li {
  padding: 14px 0;
  border-top: 1px solid var(--line);
}

.pager {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  margin-top: 42px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.pager a { text-decoration: none; max-width: 46%; }
.pager small { display: block; color: var(--ink-soft); font-size: 12px; letter-spacing: 0.14em; }
.pager strong { font-family: var(--serif); font-size: 24px; font-weight: 650; }
.pager .next { margin-left: auto; text-align: right; }

.related { margin-top: 42px; }
.related-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-top: 14px; }
.related-grid a {
  display: block;
  padding: 16px 16px 8px;
  text-decoration: none;
  background: var(--paper-2);
  border: 1px solid var(--line);
}
.related-grid a:hover { border-color: var(--ink); }
.related-grid span { color: var(--ink-soft); font-size: 13px; }
.related-grid strong { display: block; margin-top: 4px; font-family: var(--serif); font-size: 26px; font-weight: 650; }

.guide-layout { display: grid; grid-template-columns: 180px minmax(0, 1fr); gap: 42px; align-items: start; }
.guide-nav { position: sticky; top: 96px; display: flex; flex-direction: column; }
.guide-nav a {
  text-decoration: none;
  color: var(--ink-soft);
  border-left: 2px solid transparent;
  padding: 7px 0 7px 12px;
}
.guide-nav a.is-on { color: var(--ink); border-left-color: var(--lacquer); }
.guide-sec { scroll-margin-top: 96px; padding-bottom: 18px; }
.guide-sec h2 { margin: 28px 0 12px; }
.guide-sec p { font-size: 17.5px; line-height: 1.9; }

.diagrams { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 18px 0 8px; }
.diagrams figure {
  margin: 0;
  padding: 14px 12px 16px;
  background: var(--paper-2);
  border: 1px solid var(--line);
}
.diagrams svg { width: 92px; height: auto; display: block; margin: 0 auto 8px; }
.diagrams figcaption { font-size: 14px; color: var(--ink-soft); line-height: 1.6; }
.diagrams strong { display: block; color: var(--ink); font-size: 16px; margin-bottom: 4px; }

.power-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 12px 0 8px; }
.power-grid article {
  padding: 16px 16px 8px;
  background: var(--paper-2);
  border: 1px solid var(--line);
}
.power-grid h3 { margin-bottom: 8px; }
.power-grid p { margin-top: 0; color: var(--ink-soft); }

.pull {
  margin: 22px 0;
  padding: 4px 0 4px 16px;
  border-left: 3px solid var(--lacquer);
  font-family: var(--serif);
  font-size: 24px;
  line-height: 1.55;
}

.questions { list-style: none; margin: 12px 0 0; padding: 0; counter-reset: q; }
.questions li {
  counter-increment: q;
  padding: 16px 0 16px 52px;
  border-top: 1px solid var(--line);
  position: relative;
  font-size: 18px;
}
.questions li::before {
  content: counter(q, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 18px;
  color: var(--lacquer);
  font-family: var(--num);
  font-size: 13px;
  letter-spacing: 0.12em;
}

.article { max-width: 72ch; }
.article + .article { margin-top: 28px; padding-top: 28px; border-top: 1px solid var(--line); }
.article h2 { scroll-margin-top: 96px; }
.article .drop { font-size: 18px; line-height: 1.9; }
.note-index { display: flex; flex-direction: column; gap: 8px; margin: 18px 0 8px; }
.note-index a { text-decoration: none; border-bottom: 1px solid transparent; }
.note-index a:hover { border-bottom-color: var(--ink); }

.about-grid { display: grid; grid-template-columns: 0.8fr 1.2fr; gap: 36px; align-items: start; }
.about-grid h2 { margin: 0 0 12px; }
.about-block + .about-block { margin-top: 28px; }

.shelf-list { list-style: none; margin: 18px 0; padding: 0; }
.shelf-list li {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  align-items: center;
  border-top: 1px solid var(--line);
}
.shelf-list li:last-child { border-bottom: 1px solid var(--line); }
.shelf-list a {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 8px 16px;
  padding: 18px 0;
  text-decoration: none;
}
.shelf-list span { grid-row: 1 / span 2; align-self: center; font-family: var(--num); color: var(--lacquer); letter-spacing: 0.12em; }
.shelf-list strong { font-family: var(--serif); font-size: 28px; font-weight: 650; }
.shelf-list em { color: var(--ink-soft); font-style: normal; }
.shelf-empty { padding: 24px 0 12px; max-width: 36em; }
.shelf-empty p { font-size: 18px; }

.foot { background: #ddd4c4; border-top: 1px solid var(--line); padding: 42px 0 22px; }
.foot-inner {
  width: min(1120px, calc(100% - 48px));
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.1fr 0.7fr 1.3fr;
  gap: 28px;
}
.foot-brand { display: flex; gap: 12px; }
.foot-brand p { margin: 6px 0 0; }
.foot-label { margin: 0 0 8px; letter-spacing: 0.16em; font-size: 12px; color: var(--ink-soft); }
.foot a { display: block; text-decoration: none; padding: 3px 0; }
.foot a:hover { color: var(--lacquer); }
.foot-copy {
  width: min(1120px, calc(100% - 48px));
  margin: 26px auto 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  color: var(--ink-soft);
  font-size: 13px;
}

.error-page { padding: 72px 0 96px; }
.error-page h1 { max-width: 10em; }

@media (max-width: 980px) {
  .hero, .spread, .detail-hero, .guide-layout, .about-grid, .grid, .note-grid { grid-template-columns: 1fr; }
  .pillars { grid-template-columns: 1fr 1fr; }
  .diagrams { grid-template-columns: 1fr; }
  .toc a { grid-template-columns: 48px 1fr; }
  .toc-meta, .toc-line { grid-column: 2; }
  .foot-inner { grid-template-columns: 1fr 1fr; }
  .hero-copy { padding: 36px 22px 28px; }
  .hero { min-height: 0; }
  .spread a { min-height: 0; }
}

@media (max-width: 760px) {
  .wrap, .foot-inner, .foot-copy { width: min(1120px, calc(100% - 32px)); }
  .nav-btn { display: inline-flex; }
  .nav {
    position: fixed;
    z-index: 30;
    inset: 69px 0 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
    padding: 12px 24px 32px;
    background: var(--paper);
    opacity: 0;
    pointer-events: none;
    transform: translateY(-8px);
  }
  .nav.is-open { opacity: 1; pointer-events: auto; transform: none; }
  .nav a { font-family: var(--serif); font-size: 34px; line-height: 1.3; }
  .mast { padding-left: 16px; padding-right: 16px; }
  .sec-head { grid-template-columns: 1fr; }
  .sec-head .more { grid-column: 1; grid-row: auto; justify-self: start; }
  .pillars { grid-template-columns: 1fr; }
  .pillars li + li { padding-left: 0; box-shadow: none; }
  .power-grid, .related-grid, .facts, .foot-inner { grid-template-columns: 1fr; }
  .guide-nav {
    position: static;
    flex-direction: row;
    gap: 8px;
    overflow: auto;
    padding-bottom: 8px;
  }
  .guide-nav a { border-left: none; border-bottom: 2px solid transparent; padding: 6px 2px; white-space: nowrap; }
  .guide-nav a.is-on { border-bottom-color: var(--lacquer); }
  .section { padding: 56px 0; }
  .car-card h2, .shelf-list strong, .pager strong { font-size: 26px; }
  .shelf-list a { grid-template-columns: 40px 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .nav { transition: none; }
}