:root {
  --ink-indigo: #16233F;
  --indigo-mid: #24406E;
  --indigo-mist: #E4E7EE;
  --copper: #B7893F;
  --copper-light: #D9B978;
  --vermilion: #C0392B;
  --cream-paper: #F4EFE6;
  --warm-grey: #D8D1C4;
  --porcelain: #FBFAF7;
  --warm-black: #241E1A;
  --slate-grey: #6E7686;
  --moss-green: #4F6B57;
  --font-display: "Alibaba PuHuiTi", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", system-ui, -apple-system, sans-serif;
  --font-body: "Source Han Serif SC", "Noto Serif SC", "Songti SC", "STSong", "SimSun", Georgia, serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --font-label: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", system-ui, sans-serif;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 64px;
  --space-7: 96px;
  --radius-card: 8px;
  --radius-pill: 999px;
  --border-thin: 1px solid var(--warm-grey);
  --shadow-paper: 0 1px 0 var(--warm-grey), 0 8px 24px rgba(36,30,26,.06);
  --container: 1180px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--cream-paper);
  color: var(--warm-black);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--indigo-mid);
  text-decoration: none;
}

button,
input,
textarea,
select {
  font: inherit;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

p {
  margin: 0 0 1em;
}

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

.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.12em;
}

.label {
  font-family: var(--font-label);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--slate-grey);
}

.container {
  width: min(100% - 32px, var(--container));
  margin-inline: auto;
}

.container--wide {
  width: min(100% - 32px, 1280px);
  margin-inline: auto;
}

.section {
  padding: clamp(48px, 8vw, 96px) 0;
}

.section--tight {
  padding: 48px 0;
}

.section--dark {
  background: var(--ink-indigo);
  color: var(--porcelain);
}

.section--mist {
  background: var(--indigo-mist);
}

.section--paper {
  background: var(--porcelain);
}

.section__head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 32px;
}

.section__title {
  font-size: clamp(28px, 4vw, 48px);
  color: var(--ink-indigo);
}

.section--dark .section__title {
  color: var(--porcelain);
}

.section__index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--copper);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 32px;
}

.col-3 {
  grid-column: span 3;
}

.col-4 {
  grid-column: span 4;
}

.col-5 {
  grid-column: span 5;
}

.col-6 {
  grid-column: span 6;
}

.col-7 {
  grid-column: span 7;
}

.col-8 {
  grid-column: span 8;
}

.col-12 {
  grid-column: span 12;
}

.prose {
  max-width: 44ch;
}

.prose p,
.prose li {
  font-size: 17px;
  line-height: 1.85;
  color: var(--warm-black);
}

.prose h2 {
  margin-top: 2em;
  margin-bottom: 0.6em;
  font-size: clamp(24px, 3vw, 36px);
  color: var(--ink-indigo);
}

.prose a {
  color: var(--indigo-mid);
  border-bottom: 1px solid var(--copper);
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--slate-grey);
}

.breadcrumbs a {
  color: var(--indigo-mid);
}

.breadcrumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--warm-grey);
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 10px 14px;
  background: var(--porcelain);
  color: var(--ink-indigo);
  border: 1px solid var(--copper);
  border-radius: var(--radius-card);
  transform: translateY(-160%);
  transition: transform 180ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.read-progress {
  position: fixed;
  inset: 0 0 auto;
  z-index: 120;
  height: 1px;
  background: rgba(216, 209, 196, 0.55);
  pointer-events: none;
}

.read-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: var(--copper);
}

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  padding: 12px 0;
  pointer-events: none;
  transition: padding 200ms ease;
}

.site-header__shell {
  pointer-events: auto;
  width: min(100% - 24px, 1180px);
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 8px 8px 8px 20px;
  background: var(--ink-indigo);
  color: var(--porcelain);
  border: 1px solid rgba(183, 137, 63, 0.38);
  border-radius: var(--radius-pill);
  box-shadow: 0 8px 24px rgba(22, 35, 63, 0.18);
  transition: padding 200ms ease, transform 200ms ease;
}

.site-header.is-scrolled .site-header__shell {
  padding-top: 6px;
  padding-bottom: 6px;
  transform: translateY(-2px);
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
  color: var(--porcelain);
  text-decoration: none;
}

.brand__mark {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 800;
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.brand__line {
  font-family: var(--font-label);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--copper-light);
  white-space: nowrap;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  padding: 8px 12px;
  background: transparent;
  color: var(--porcelain);
  border: 1px solid var(--copper);
  border-radius: var(--radius-pill);
  cursor: pointer;
}

.nav-toggle__label {
  font-family: var(--font-label);
  font-size: 12px;
  letter-spacing: 0.1em;
}

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  width: 14px;
}

.nav-toggle__bars span {
  display: block;
  height: 1px;
  background: currentColor;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-left: auto;
}

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px;
}

.site-nav__list a {
  position: relative;
  display: block;
  padding: 8px 10px;
  color: var(--porcelain);
  font-family: var(--font-label);
  font-size: 13px;
  letter-spacing: 0.06em;
  border-radius: var(--radius-pill);
  text-decoration: none;
  transition: color 180ms ease, background 180ms ease;
}

.site-nav__list a:hover {
  color: var(--copper-light);
  background: rgba(251, 250, 247, 0.08);
}

.site-nav__list a[aria-current="page"] {
  color: var(--porcelain);
  background: rgba(183, 137, 63, 0.18);
}

.site-nav__list a[aria-current="page"]::before {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 2px;
  width: 4px;
  height: 4px;
  margin-left: -2px;
  border-radius: 50%;
  background: var(--vermilion);
}

.site-nav__aux {
  display: flex;
  align-items: center;
  gap: 10px;
}

.update-badge {
  padding-left: 10px;
  border-left: 1px solid rgba(183, 137, 63, 0.5);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--copper-light);
  white-space: nowrap;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 10px 16px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-label);
  font-size: 13px;
  letter-spacing: 0.08em;
  text-decoration: none;
  cursor: pointer;
  transition: background 160ms ease, color 160ms ease, border-color 160ms ease;
}

.button--vermilion {
  background: var(--vermilion);
  color: var(--porcelain);
  border-color: var(--vermilion);
}

.button--vermilion:hover {
  background: #A93226;
  border-color: #A93226;
}

.button--ghost {
  background: transparent;
  color: var(--ink-indigo);
  border-color: var(--copper);
}

.button--ghost:hover {
  background: var(--copper);
  color: var(--ink-indigo);
}

.button--light {
  background: var(--porcelain);
  color: var(--ink-indigo);
  border-color: var(--porcelain);
}

.site-footer {
  padding: clamp(48px, 7vw, 80px) 0 32px;
  background: var(--ink-indigo);
  color: var(--porcelain);
  border-top: 1px solid rgba(183, 137, 63, 0.35);
}

.site-footer__inner {
  width: min(100% - 32px, var(--container));
  margin-inline: auto;
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 5fr);
  gap: 40px 48px;
  align-items: start;
}

.footer-masthead {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--porcelain);
  text-decoration: none;
}

.footer-intro {
  max-width: 36em;
  margin: 0;
  color: rgba(251, 250, 247, 0.72);
  font-size: 14px;
  line-height: 1.8;
}

.footer-meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--copper-light);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.footer-col h3 {
  margin-bottom: 12px;
  font-family: var(--font-label);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: var(--copper-light);
  text-transform: uppercase;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-col a {
  color: rgba(251, 250, 247, 0.84);
  font-size: 14px;
  text-decoration: none;
}

.footer-col a:hover {
  color: var(--copper-light);
}

.footer-col a[aria-current="page"] {
  color: var(--porcelain);
}

.footer-col a[aria-current="page"]::before {
  content: "·";
  margin-right: 6px;
  color: var(--vermilion);
}

.footer-contact {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding-top: 24px;
  border-top: 1px solid rgba(183, 137, 63, 0.35);
}

.footer-contact__line {
  margin: 0;
  color: rgba(251, 250, 247, 0.76);
  font-size: 13px;
}

.footer-legal,
.footer-update,
.footer-copyright {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: rgba(251, 250, 247, 0.6);
}

.archive-card {
  position: relative;
  z-index: 0;
  padding: 28px 28px 24px;
  background: var(--porcelain);
  border: 1px solid var(--warm-grey);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-paper);
  transition: border-color 160ms ease, transform 160ms ease;
}

.archive-card::before,
.archive-card::after {
  content: "";
  position: absolute;
  z-index: -1;
  border: 1px solid var(--warm-grey);
  border-radius: var(--radius-card);
  pointer-events: none;
}

.archive-card::before {
  inset: 8px -8px -8px 8px;
}

.archive-card::after {
  inset: 16px -16px -16px 16px;
  opacity: 0.45;
}

.archive-card:hover {
  border-color: var(--copper);
  transform: translateY(-2px);
}

.archive-card__index {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--copper);
}

.archive-card__title {
  margin-bottom: 10px;
  font-size: clamp(18px, 2.2vw, 24px);
  color: var(--ink-indigo);
}

.archive-card__text {
  margin-bottom: 18px;
  color: var(--warm-black);
  font-size: 15px;
  line-height: 1.8;
}

.archive-card__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 16px;
  border-top: 1px solid var(--copper);
  font-family: var(--font-label);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--slate-grey);
}

.archive-card__link {
  color: var(--indigo-mid);
  font-weight: 600;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background: transparent;
  border: 1px solid var(--copper);
  border-radius: var(--radius-pill);
  font-family: var(--font-label);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--copper);
  text-transform: uppercase;
}

.tag--vermilion {
  border-color: var(--vermilion);
  color: var(--vermilion);
}

.tag--moss {
  border-color: var(--moss-green);
  color: var(--moss-green);
}

.status-dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--slate-grey);
}

.status-dot--moss {
  background: var(--moss-green);
}

.status-dot--copper {
  background: var(--copper);
}

.status-dot--vermilion {
  background: var(--vermilion);
}

.media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--warm-grey);
  border-radius: var(--radius-card);
  background: var(--indigo-mist);
}

.media-frame img,
.media-frame__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--hero {
  aspect-ratio: 16 / 10;
}

.media-frame--square {
  aspect-ratio: 1 / 1;
}

.media-frame--portrait {
  aspect-ratio: 3 / 4;
}

.media-frame__caption {
  position: absolute;
  left: 12px;
  bottom: 12px;
  padding: 6px 8px;
  background: rgba(22, 35, 63, 0.82);
  color: var(--porcelain);
  border: 1px solid rgba(183, 137, 63, 0.5);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
}

.rail {
  overflow-x: auto;
  scrollbar-color: var(--copper) var(--indigo-mist);
  scrollbar-width: thin;
}

.rail__track {
  display: flex;
  gap: 24px;
  min-width: max-content;
  padding-bottom: 12px;
}

.rail__item {
  flex: 0 0 auto;
  width: min(320px, 78vw);
}

.rail::-webkit-scrollbar {
  height: 6px;
}

.rail::-webkit-scrollbar-track {
  background: var(--indigo-mist);
}

.rail::-webkit-scrollbar-thumb {
  background: var(--copper);
  border-radius: var(--radius-pill);
}

.scale {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--warm-grey);
  border: 1px solid var(--warm-grey);
}

.scale__item {
  position: relative;
  padding: 24px;
  background: var(--porcelain);
}

.scale__item:hover,
.scale__item:focus-within {
  background: var(--indigo-mist);
}

.scale__marker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--copper);
}

.scale__title {
  margin: 8px 0;
  font-family: var(--font-display);
  font-size: 20px;
  color: var(--ink-indigo);
}

.scale__detail {
  display: none;
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--copper);
  font-size: 14px;
}

.scale__item:hover .scale__detail,
.scale__item:focus-within .scale__detail {
  display: block;
}

.compare-table {
  width: 100%;
  border: 1px solid var(--warm-grey);
  border-collapse: collapse;
  background: var(--porcelain);
}

.compare-table th,
.compare-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--warm-grey);
  text-align: left;
  font-size: 14px;
}

.compare-table th {
  background: var(--indigo-mist);
  font-family: var(--font-label);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ink-indigo);
}

.compare-table tbody tr:nth-child(even) {
  background: rgba(228, 231, 238, 0.45);
}

.compare-table tbody tr:hover {
  background: rgba(183, 137, 63, 0.12);
}

.compare-table tbody tr.is-active {
  background: rgba(192, 57, 43, 0.08);
  box-shadow: inset 3px 0 0 var(--vermilion);
}

.accordion {
  overflow: hidden;
  background: var(--porcelain);
  border: 1px solid var(--warm-grey);
  border-radius: var(--radius-card);
}

.accordion__item + .accordion__item {
  border-top: 1px solid var(--warm-grey);
}

.accordion__trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 20px;
  background: transparent;
  border: 0;
  color: var(--ink-indigo);
  font-family: var(--font-display);
  font-size: 16px;
  text-align: left;
  cursor: pointer;
}

.accordion__trigger::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--copper);
}

.accordion__item[data-open="true"] .accordion__trigger::after {
  content: "–";
}

.accordion__panel {
  padding: 0 20px 20px;
  color: var(--warm-black);
  font-size: 15px;
  line-height: 1.8;
}

.js .accordion__item:not([data-open="true"]) .accordion__panel {
  display: none;
}

.note {
  padding: 18px 20px;
  background: var(--indigo-mist);
  border-left: 3px solid var(--copper);
  color: var(--ink-indigo);
  font-size: 14px;
}

.note--vermilion {
  background: rgba(192, 57, 43, 0.06);
  border-left-color: var(--vermilion);
}

.horizontal-rule {
  margin: 32px 0;
  border: 0;
  border-top: 1px solid var(--warm-grey);
}

.section-toc {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.section-toc a {
  padding: 6px 0 6px 10px;
  border-left: 2px solid transparent;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--slate-grey);
  text-decoration: none;
}

.section-toc a.is-active {
  border-left-color: var(--vermilion);
  color: var(--ink-indigo);
}

@media (max-width: 960px) {
  .container,
  .container--wide {
    width: min(100% - 24px, var(--container));
  }

  .grid-12 {
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: 24px;
  }

  .col-3,
  .col-4,
  .col-5 {
    grid-column: span 3;
  }

  .col-6,
  .col-7,
  .col-8 {
    grid-column: span 6;
  }

  .site-header {
    padding: 10px 0;
  }

  .site-header__shell {
    flex-wrap: wrap;
    align-items: center;
    padding: 8px 10px 8px 16px;
    border-radius: 8px;
  }

  .brand__line {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
  }

  html:not(.js) .nav-toggle {
    display: none;
  }

  .site-nav {
    display: none;
    order: 3;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    margin: 8px 0 0;
    padding-top: 8px;
    border-top: 1px solid rgba(183, 137, 63, 0.4);
  }

  html:not(.js) .site-nav {
    display: flex;
  }

  .site-header[data-open="true"] .site-nav {
    display: flex;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .site-nav__list a {
    padding: 10px 12px;
    border-radius: 8px;
  }

  .site-nav__aux {
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    padding-top: 8px;
  }

  .update-badge {
    padding-left: 0;
    border-left: 0;
  }

  .site-footer__inner {
    grid-template-columns: 1fr;
  }

  .scale {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .grid-12 {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .col-3,
  .col-4,
  .col-5,
  .col-6,
  .col-7,
  .col-8,
  .col-12 {
    grid-column: span 1;
  }

  .section__head {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-nav {
    grid-template-columns: 1fr;
  }

  .footer-contact {
    flex-direction: column;
    align-items: flex-start;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .site-header.is-scrolled .site-header__shell,
  .archive-card:hover {
    transform: none;
  }
}