:root {
  --youtu-blue: #0052d9;
  --link-blue: #0066bf;
  --paper-blue: #edf5fe;
  --soft-blue: #eef5fd;
  --paper-text: #1c2b33;
  --paper-bg: #f1f4f7;
  --frame-blue: #36558c;
  --ink-muted: #5b6b76;
  --line: #d7e2f0;
  --cream: #fcf9f2;
  --gold: #ffe47b;
  --green: #228b22;
  --white: #ffffff;
  --shadow: 0 18px 50px rgba(28, 43, 51, 0.10);
  --content: 1180px;
  --header-offset: 74px;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-serif: "Crimson Pro", "Iowan Old Style", Georgia, serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-offset) + 18px);
  overflow-x: hidden;
}

body {
  margin: 0;
  padding-top: var(--header-offset);
  color: var(--paper-text);
  background: var(--white);
  font-family: var(--font-sans);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

a {
  color: var(--link-blue);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

code,
pre {
  font-family: var(--font-mono);
}

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  min-height: 74px;
  padding: 10px 28px;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid rgba(215, 226, 240, 0.9);
  backdrop-filter: blur(12px);
  width: 100%;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 240px;
  color: var(--paper-text);
  font-weight: 800;
}

.brand img {
  width: 126px;
  height: auto;
}

.brand span {
  white-space: nowrap;
  overflow-wrap: anywhere;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 6px;
  max-width: 100%;
  overflow-x: auto;
  scrollbar-width: thin;
}

.site-nav a {
  flex: 0 0 auto;
  padding: 9px 10px;
  border-bottom: 2px solid transparent;
  color: var(--ink-muted);
  font-size: 0.92rem;
  font-weight: 700;
  white-space: nowrap;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--youtu-blue);
  border-bottom-color: var(--youtu-blue);
  text-decoration: none;
}

.section-band {
  width: 100%;
  padding: 80px 24px;
  background: var(--white);
}

.section-band.tinted {
  background: var(--paper-bg);
}

.section-inner {
  width: min(var(--content), 100%);
  margin: 0 auto;
}

.hero {
  padding-top: 72px;
  background: var(--paper-blue);
  border-bottom: 1px solid var(--line);
}

.hero-inner {
  text-align: center;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--frame-blue);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
h4,
p {
  letter-spacing: 0;
}

h1 {
  max-width: 920px;
  margin: 0 auto;
  color: var(--paper-text);
  font-size: 2.18rem;
  line-height: 1.12;
  overflow-wrap: anywhere;
}

h1 span {
  display: inline;
}

h2 {
  margin: 0;
  color: var(--paper-text);
  font-size: 2.35rem;
  line-height: 1.15;
}

h3 {
  margin: 0 0 12px;
  color: var(--frame-blue);
  font-size: 1.32rem;
}

h4 {
  margin: 0 0 8px;
  color: var(--paper-text);
  font-size: 1rem;
}

p {
  font-size: 1.02rem;
  line-height: 1.72;
}

.subtitle {
  margin: 20px 0 0;
  color: var(--youtu-blue);
  font-size: 1.45rem;
  font-weight: 800;
}

.lead {
  max-width: 790px;
  margin: 18px auto 0;
  color: var(--ink-muted);
  font-size: 1.12rem;
}

.author-block {
  display: grid;
  gap: 6px;
  margin: 24px auto 0;
  color: var(--paper-text);
  font-weight: 700;
}

.author-block p {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px 12px;
  margin: 0;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin: 28px 0 34px;
  max-width: 100%;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 10px 16px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--white);
  color: var(--paper-text);
  font-weight: 800;
  cursor: pointer;
  flex: 0 1 auto;
}

.button.primary {
  border-color: var(--youtu-blue);
  background: var(--youtu-blue);
  color: var(--white);
}

.button:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.hero-figure,
.figure-wide,
.figure-frame {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.hero-figure {
  margin-top: 10px;
  width: 100%;
  max-width: 100%;
}

.hero-art {
  width: 100%;
  height: auto;
  object-fit: contain;
  background: var(--white);
}

figcaption {
  padding: 12px 16px;
  color: var(--ink-muted);
  font-family: var(--font-serif);
  font-size: 0.9rem;
  font-style: italic;
  line-height: 1.5;
  border-top: 1px solid var(--line);
  background: rgba(252, 249, 242, 0.55);
}

.section-heading {
  max-width: 820px;
  margin-bottom: 34px;
}

.section-heading p:last-child {
  color: var(--ink-muted);
}

.abstract-box {
  padding: 26px;
  border: 1px solid var(--line);
  border-left: 5px solid var(--youtu-blue);
  border-radius: 8px;
  background: var(--soft-blue);
}

.abstract-box p {
  margin: 0;
  font-family: var(--font-serif);
}

.contribution-grid,
.resource-grid,
.table-grid {
  display: grid;
  gap: 16px;
}

.contribution-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: 18px;
}

.info-card,
.table-card,
.callout,
.citation-box {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: 0 12px 36px rgba(28, 43, 51, 0.07);
}

.info-card {
  padding: 18px;
}

.info-card span {
  display: inline-flex;
  margin-bottom: 16px;
  color: var(--youtu-blue);
  font-weight: 900;
}

.info-card p,
.table-card p,
.callout p {
  margin: 0;
  color: var(--ink-muted);
}

.future-content {
  display: grid;
  gap: 22px;
  margin-top: 28px;
}

.future-block {
  display: grid;
  gap: 14px;
}

.future-block > p {
  max-width: 960px;
  margin: 0;
  color: var(--ink-muted);
}

.future-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.future-grid-wide {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.future-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: 0 12px 36px rgba(28, 43, 51, 0.06);
}

.future-card p {
  margin: 0;
  color: var(--ink-muted);
  font-size: 0.94rem;
  line-height: 1.62;
}

.figure-wide {
  margin-bottom: 22px;
}

.figure-wide.roadmap-map,
.figure-wide.compact {
  width: min(820px, 100%);
  max-width: 820px;
  margin-right: auto;
  margin-left: auto;
}

.figure-wide.roadmap-map img,
.figure-wide.compact img {
  width: 100%;
  max-width: none;
}

.paired-panels {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
  align-items: start;
}

.paired-panels article > p {
  min-height: 84px;
  color: var(--ink-muted);
}

.figure-frame img,
.figure-wide img {
  width: 100%;
  background: var(--white);
}

.table-group,
.stage-list {
  margin-top: 28px;
}

.table-intro {
  color: var(--ink-muted);
}

.paper-table {
  margin-top: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  overflow: hidden;
}

.paper-table summary {
  padding: 15px 18px;
  color: var(--frame-blue);
  font-weight: 900;
  cursor: pointer;
}

.paper-table[open] summary {
  border-bottom: 1px solid var(--line);
}

.paper-table p {
  margin: 0;
  padding: 0 18px 18px;
  color: var(--ink-muted);
}

.table-scroll {
  overflow-x: auto;
  border-top: 1px solid var(--line);
  -webkit-overflow-scrolling: touch;
}

table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
  background: var(--white);
}

th,
td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
  font-size: 0.92rem;
  line-height: 1.45;
}

th {
  background: var(--paper-blue);
  color: var(--frame-blue);
  font-weight: 900;
}

.catalog-table {
  min-width: 1320px;
}

.catalog-table th,
.catalog-table td,
.benchmark-table th,
.benchmark-table td {
  padding: 8px 10px;
  font-size: 0.82rem;
  white-space: nowrap;
}

.source-table {
  min-width: 980px;
  table-layout: fixed;
}

.source-table th,
.source-table td {
  font-size: 0.84rem;
}

.benchmark-table {
  min-width: 1040px;
}

.metric-table {
  min-width: 1780px;
}

.benchmark-table thead tr:first-child th:first-child,
.benchmark-table tbody td:first-child {
  position: sticky;
  left: 0;
  z-index: 1;
  background: var(--white);
  box-shadow: 1px 0 0 var(--line);
  font-weight: 800;
}

.benchmark-table thead tr:first-child th:first-child {
  z-index: 3;
  background: var(--paper-blue);
}

.metric-table .group-row th {
  text-align: center;
}

.table-note {
  font-size: 0.82rem;
  line-height: 1.55;
}

.table-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 10px;
}

.table-card {
  padding: 18px;
}

.table-card .table-scroll {
  margin-top: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.callout {
  margin-top: 26px;
  padding: 24px;
  border-left: 5px solid var(--green);
  background: var(--cream);
}

.resources-band {
  background: var(--paper-text);
  color: var(--white);
}

.resources-band .section-heading h2,
.resources-band .section-heading p,
.resources-band .eyebrow {
  color: var(--white);
}

.resource-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.resource-link {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 12px;
  align-items: center;
  min-height: 78px;
  padding: 16px;
  border: 1px solid rgba(215, 226, 240, 0.18);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  color: var(--white);
  font-weight: 900;
}

.resource-link:hover {
  border-color: rgba(255, 255, 255, 0.5);
  text-decoration: none;
}

.resource-link img {
  width: 34px;
  height: 34px;
  object-fit: contain;
}

.resource-link span {
  display: block;
  grid-column: 2;
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.86rem;
  font-weight: 600;
}

.citation-box {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 18px;
  margin-top: 24px;
  padding: 22px;
  background: var(--white);
  color: var(--paper-text);
}

.citation-box pre {
  grid-column: 1 / -1;
  margin: 0;
  padding: 18px;
  overflow-x: auto;
  border-radius: 8px;
  background: #101820;
  color: #edf5fe;
  font-size: 0.9rem;
  line-height: 1.55;
}

.footer-logos {
  display: flex;
  align-items: center;
  gap: 22px;
  margin-top: 26px;
}

.footer-logos img {
  max-width: 220px;
  height: 62px;
  object-fit: contain;
  padding: 8px;
  border-radius: 8px;
  background: var(--white);
}

.site-footer {
  padding: 26px 24px;
  background: #101820;
  color: rgba(255, 255, 255, 0.72);
  text-align: center;
}

.site-footer p {
  margin: 0;
  font-size: 0.95rem;
}

@media (max-width: 980px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    overflow: hidden;
  }

  .brand {
    min-width: 0;
    max-width: 100%;
  }

  .site-nav {
    width: 100%;
    justify-content: flex-start;
    flex-wrap: wrap;
    overflow-x: visible;
  }

  h1 {
    font-size: 2.18rem;
  }

  .contribution-grid,
  .future-grid,
  .future-grid-wide,
  .resource-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .paired-panels,
  .table-grid {
    grid-template-columns: 1fr;
  }

  .paired-panels article > p {
    min-height: 0;
  }
}

@media (max-width: 640px) {
  .site-header {
    padding: 10px 12px;
  }

  .brand span {
    white-space: normal;
    font-size: 0.92rem;
  }

  .brand img {
    width: 112px;
  }

  .site-nav {
    gap: 2px;
  }

  .site-nav a {
    padding: 7px 6px;
    font-size: 0.82rem;
  }

  .section-band {
    padding: 54px 16px;
  }

  .hero-inner,
  .hero-figure,
  .figure-wide,
  .figure-frame {
    max-width: 100%;
  }

  .hero-figure {
    width: 100%;
  }

  .hero-figure img,
  .hero-figure figcaption {
    width: 100%;
    max-width: 100%;
    min-width: 0;
    overflow-wrap: anywhere;
  }

  .section-inner {
    width: 100%;
    max-width: calc(100vw - 32px);
    min-width: 0;
  }

  h1 {
    font-size: 1.5rem;
    line-height: 1.18;
  }

  h1 span {
    display: block;
  }

  h2 {
    font-size: 1.75rem;
  }

  .subtitle {
    font-size: 1rem;
    max-width: 280px;
    margin-right: auto;
    margin-left: auto;
    overflow-wrap: anywhere;
  }

  .lead {
    max-width: 292px;
    font-size: 0.98rem;
  }

  .author-block {
    max-width: 270px;
  }

  .hero-actions {
    width: min(310px, 100%);
    margin-right: auto;
    margin-left: auto;
  }

  .hero-actions .button {
    flex: 1 1 130px;
  }

  .contribution-grid,
  .future-grid,
  .future-grid-wide,
  .resource-grid {
    grid-template-columns: 1fr;
  }

  .citation-box {
    grid-template-columns: 1fr;
  }

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