:root {
  color-scheme: light;
  --paper: #f4f3ef;
  --paper-deep: #ebe9e2;
  --surface: #fbfaf6;
  --ink: #161b22;
  --ink-soft: #4c545f;
  --muted: #777d84;
  --line: rgba(22, 27, 34, 0.14);
  --line-strong: rgba(22, 27, 34, 0.28);
  --accent: #e55f49;
  --accent-soft: #f5c8bd;
  --signal: #b2c9d2;
  --shadow: 0 24px 80px rgba(23, 28, 35, 0.09);
}

html.dark {
  color-scheme: dark;
  --paper: #11151a;
  --paper-deep: #171c22;
  --surface: #1a2027;
  --ink: #edf0f3;
  --ink-soft: #bdc4cc;
  --muted: #8f99a4;
  --line: rgba(237, 240, 243, 0.12);
  --line-strong: rgba(237, 240, 243, 0.26);
  --accent: #ff7a63;
  --accent-soft: #69382f;
  --signal: #6d939f;
  --shadow: 0 28px 90px rgba(0, 0, 0, 0.3);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 5%, rgba(229, 95, 73, 0.11), transparent 28rem),
    radial-gradient(circle at 96% 28%, rgba(120, 158, 172, 0.12), transparent 24rem),
    var(--paper);
  font-family: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
  transition: color 180ms ease, background-color 180ms ease;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -2;
  content: "";
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 72px 72px;
  opacity: 0.24;
  mask-image: linear-gradient(to bottom, black, transparent 82%);
}

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

button {
  color: inherit;
  font: inherit;
}

img {
  max-width: 100%;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 20;
  padding: 10px 14px;
  color: var(--paper);
  background: var(--ink);
  transform: translateY(-150%);
}

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

.site-shell {
  width: min(1220px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  min-height: 96px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: grid;
  grid-template-columns: 42px auto;
  grid-template-rows: auto auto;
  column-gap: 12px;
  align-items: center;
  font-family: "Manrope", sans-serif;
}

.brand > span {
  grid-row: 1 / 3;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  color: var(--paper);
  background: var(--ink);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.brand strong {
  align-self: end;
  font-size: 16px;
  line-height: 1.1;
}

.brand small {
  align-self: start;
  color: var(--muted);
  font: 500 10px/1.4 "JetBrains Mono", monospace;
  letter-spacing: 0.12em;
}

.site-header nav {
  display: flex;
  align-items: center;
  gap: 28px;
  font: 600 13px/1.4 "Manrope", "Noto Sans SC", sans-serif;
}

.site-header nav a {
  position: relative;
  color: var(--ink-soft);
}

.site-header nav a::after {
  position: absolute;
  right: 0;
  bottom: -7px;
  left: 0;
  height: 2px;
  content: "";
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 180ms ease;
}

.site-header nav a:hover::after,
.site-header nav a[aria-current="page"]::after {
  transform: scaleX(1);
  transform-origin: left;
}

.theme-toggle {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: transparent;
  cursor: pointer;
}

.theme-toggle:hover {
  border-color: var(--line-strong);
}

.eyebrow,
.section-index {
  margin: 0;
  color: var(--accent);
  font: 600 11px/1.5 "JetBrains Mono", monospace;
  letter-spacing: 0.11em;
}

.research-hero {
  min-height: 690px;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(380px, 0.92fr);
  gap: 76px;
  align-items: center;
  padding: 72px 0 80px;
  border-bottom: 1px solid var(--line);
}

.hero-copy h1 {
  max-width: 760px;
  margin: 24px 0 30px;
  font: 700 clamp(50px, 6.2vw, 86px)/1.03 "Manrope", "Noto Sans SC", sans-serif;
  letter-spacing: -0.055em;
}

.hero-copy h1 em {
  color: var(--accent);
  font-style: normal;
}

.hero-intro {
  max-width: 690px;
  margin: 0;
  color: var(--ink-soft);
  font-size: 17px;
  line-height: 1.9;
}

.hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 13px 28px;
  margin-top: 38px;
  color: var(--muted);
  font-size: 12px;
}

.hero-facts span {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
}

.hero-facts b {
  color: var(--ink);
  font: 700 22px/1 "JetBrains Mono", monospace;
}

.hero-visual {
  position: relative;
  margin: 0;
  padding: 18px 18px 52px;
  background: var(--surface);
  box-shadow: var(--shadow);
  transform: rotate(1.5deg);
}

.hero-visual::before {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 54px;
  height: 5px;
  content: "";
  background: var(--accent);
}

.hero-visual img {
  width: 100%;
  aspect-ratio: 3 / 2;
  display: block;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.02);
}

.hero-visual figcaption {
  position: absolute;
  right: 18px;
  bottom: 17px;
  color: var(--muted);
  font: 500 10px/1.4 "JetBrains Mono", monospace;
  letter-spacing: 0.12em;
}

.editorial-note,
.research-boundary {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: 38px;
  padding: 90px 0;
  border-bottom: 1px solid var(--line);
}

.editorial-note > div {
  display: grid;
  grid-template-columns: minmax(280px, 0.8fr) minmax(320px, 1.2fr);
  gap: 56px;
  align-items: start;
}

.editorial-note h2,
.research-boundary h2,
.section-lead h2 {
  margin: 0;
  font: 700 clamp(30px, 4vw, 52px)/1.13 "Manrope", "Noto Sans SC", sans-serif;
  letter-spacing: -0.035em;
}

.editorial-note p:last-child,
.research-boundary p:last-child,
.section-lead > p:last-child {
  margin: 0;
  color: var(--ink-soft);
  font-size: 16px;
}

.article-section {
  padding: 96px 0 112px;
}

.section-lead {
  display: grid;
  grid-template-columns: 180px minmax(260px, 0.7fr) minmax(320px, 1fr);
  gap: 38px;
  align-items: end;
  margin-bottom: 58px;
}

.article-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line-strong);
  border-left: 1px solid var(--line);
}

.article-card {
  min-height: 430px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(251, 250, 246, 0.42);
  transition: background 180ms ease;
}

html.dark .article-card {
  background: rgba(26, 32, 39, 0.35);
}

.article-card:hover {
  background: var(--surface);
}

.article-card > a {
  height: 100%;
  display: flex;
  flex-direction: column;
  padding: 36px;
}

.article-card-featured {
  grid-column: 1 / 3;
  min-height: 380px;
}

.article-card-featured > a {
  padding-right: 18%;
}

.article-card-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--muted);
  font: 500 10px/1.4 "JetBrains Mono", monospace;
  letter-spacing: 0.05em;
}

.article-number {
  color: var(--accent);
  font-size: 16px;
  font-weight: 700;
}

.article-card h2 {
  max-width: 760px;
  margin: 44px 0 18px;
  font: 700 clamp(25px, 3vw, 40px)/1.25 "Manrope", "Noto Sans SC", sans-serif;
  letter-spacing: -0.03em;
}

.article-card p {
  max-width: 800px;
  margin: 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.article-card .tag-row {
  margin-top: 26px;
}

.tag-row span {
  padding: 5px 9px;
  border: 1px solid var(--line);
  color: var(--muted);
  font: 500 10px/1.3 "JetBrains Mono", "Noto Sans SC", monospace;
}

.read-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: auto;
  padding-top: 34px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
}

.read-link b {
  transition: transform 180ms ease;
}

.article-card:hover .read-link b {
  transform: translate(3px, -3px);
}

.research-boundary {
  grid-template-columns: 180px minmax(280px, 0.65fr) minmax(320px, 1fr);
  align-items: start;
  border-top: 1px solid var(--line);
}

.site-footer {
  min-height: 120px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  color: var(--muted);
  font: 500 11px/1.5 "JetBrains Mono", monospace;
}

.reading-progress {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  z-index: 30;
  height: 3px;
}

.reading-progress span {
  width: 0;
  height: 100%;
  display: block;
  background: var(--accent);
}

.article-header {
  max-width: 970px;
  margin: 0 auto;
  padding: 68px 0 64px;
  border-bottom: 1px solid var(--line);
}

.back-link {
  display: inline-block;
  margin-bottom: 52px;
  color: var(--muted);
  font-size: 13px;
}

.back-link:hover {
  color: var(--accent);
}

.article-header h1 {
  max-width: 900px;
  margin: 22px 0 28px;
  font: 700 clamp(40px, 6vw, 72px)/1.12 "Manrope", "Noto Sans SC", sans-serif;
  letter-spacing: -0.05em;
}

.article-deck {
  max-width: 820px;
  margin: 0;
  color: var(--ink-soft);
  font-size: 18px;
  line-height: 1.85;
}

.article-byline {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  margin: 34px 0 20px;
  color: var(--muted);
  font: 500 11px/1.5 "JetBrains Mono", monospace;
}

.article-layout {
  max-width: 970px;
  display: grid;
  grid-template-columns: 150px minmax(0, 720px);
  gap: 70px;
  margin: 0 auto;
  padding: 84px 0 100px;
  align-items: start;
}

.article-rail {
  position: sticky;
  top: 28px;
  display: grid;
  gap: 10px;
  color: var(--muted);
  font: 500 10px/1.6 "JetBrains Mono", monospace;
  letter-spacing: 0.08em;
}

.article-rail::before {
  width: 32px;
  height: 4px;
  margin-bottom: 12px;
  content: "";
  background: var(--accent);
}

.article-rail b {
  color: var(--ink);
}

.prose {
  min-width: 0;
}

.prose > :first-child {
  margin-top: 0;
}

.prose p {
  margin: 0 0 26px;
  color: var(--ink-soft);
  font-size: 16px;
  line-height: 1.95;
}

.prose h2 {
  margin: 72px 0 24px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font: 700 clamp(26px, 3vw, 36px)/1.35 "Manrope", "Noto Sans SC", sans-serif;
  letter-spacing: -0.025em;
}

.prose h3 {
  margin: 46px 0 18px;
  font-size: 21px;
}

.prose ul,
.prose ol {
  margin: 0 0 30px;
  padding-left: 1.4em;
  color: var(--ink-soft);
}

.prose li {
  margin: 10px 0;
  padding-left: 6px;
}

.prose li::marker {
  color: var(--accent);
  font-weight: 700;
}

.prose strong {
  color: var(--ink);
}

.prose code {
  padding: 0.18em 0.38em;
  color: var(--ink);
  background: var(--paper-deep);
  font: 500 0.88em/1.4 "JetBrains Mono", monospace;
}

.prose pre {
  overflow-x: auto;
  margin: 32px 0;
  padding: 24px 26px;
  border-left: 4px solid var(--accent);
  color: var(--ink);
  background: var(--paper-deep);
}

.prose pre code {
  padding: 0;
  background: transparent;
  font-size: 12px;
  line-height: 1.8;
}

.prose blockquote {
  margin: 42px 0;
  padding: 24px 0 24px 28px;
  border-left: 4px solid var(--accent);
  color: var(--ink);
  font-size: 17px;
  font-weight: 600;
}

.author-note {
  max-width: 970px;
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  margin: 0 auto;
  padding: 36px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.author-note img {
  width: 72px;
  height: 72px;
  object-fit: cover;
  filter: grayscale(1);
}

.author-note h2 {
  margin: 3px 0 8px;
  font: 700 23px/1.3 "Manrope", sans-serif;
}

.author-note div > p:last-child {
  max-width: 700px;
  margin: 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.article-nav {
  max-width: 970px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 58px auto 28px;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.article-nav a,
.article-nav-empty {
  min-height: 140px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 24px 30px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.article-nav a:hover {
  background: var(--surface);
}

.article-nav small {
  margin-bottom: 8px;
  color: var(--accent);
  font: 500 10px/1.4 "JetBrains Mono", monospace;
}

.article-nav strong {
  font-size: 15px;
  line-height: 1.6;
}

@media (max-width: 900px) {
  .research-hero {
    grid-template-columns: 1fr;
    gap: 52px;
  }

  .hero-visual {
    width: min(620px, 94%);
    margin-left: auto;
  }

  .editorial-note,
  .research-boundary,
  .section-lead {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .editorial-note > div {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .article-layout {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .article-rail {
    position: static;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px 18px;
  }

  .article-rail::before {
    margin: 0;
  }

  .article-rail p {
    display: none;
  }
}

@media (max-width: 680px) {
  .site-shell {
    width: min(100% - 28px, 1220px);
  }

  .site-header {
    min-height: 82px;
  }

  .site-header nav {
    gap: 15px;
  }

  .site-header nav a:first-child,
  .site-header nav a:nth-child(3) {
    display: none;
  }

  .brand small {
    display: none;
  }

  .brand {
    grid-template-rows: 1fr;
  }

  .research-hero {
    min-height: 0;
    padding: 58px 0 70px;
  }

  .hero-copy h1 {
    margin-top: 18px;
    font-size: clamp(42px, 13vw, 62px);
  }

  .hero-intro {
    font-size: 15px;
  }

  .hero-facts {
    display: grid;
  }

  .hero-visual {
    width: 96%;
    padding: 12px 12px 42px;
  }

  .editorial-note,
  .research-boundary,
  .article-section {
    padding: 66px 0;
  }

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

  .article-card-featured {
    grid-column: auto;
  }

  .article-card-featured > a,
  .article-card > a {
    padding: 28px 24px;
  }

  .article-card {
    min-height: 390px;
  }

  .article-card h2 {
    margin-top: 34px;
    font-size: 28px;
  }

  .article-header {
    padding: 46px 0 52px;
  }

  .back-link {
    margin-bottom: 34px;
  }

  .article-header h1 {
    font-size: clamp(38px, 11vw, 54px);
  }

  .article-deck {
    font-size: 16px;
  }

  .article-layout {
    padding: 58px 0 76px;
  }

  .prose p {
    font-size: 15px;
  }

  .prose h2 {
    margin-top: 58px;
  }

  .author-note {
    grid-template-columns: 54px 1fr;
  }

  .author-note img {
    width: 54px;
    height: 54px;
  }

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

  .site-footer {
    min-height: 100px;
    align-items: flex-start;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}