@import url("https://fonts.googleapis.com/css2?family=Source+Sans+3:wght@400;500;600;700&family=Source+Serif+4:opsz,wght@8..60,400;8..60,600&display=swap");

:root {
  --ink: #172033;
  --navy: #173b63;
  --blue: #2e6da4;
  --blue-light: #eaf2f8;
  --muted: #5f6b7a;
  --paper: #ffffff;
  --surface: #f6f8fa;
  --line: #d8e0e8;
  --max-width: 1160px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Source Sans 3", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--blue);
}

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 20;
  padding: 0.65rem 1rem;
  background: var(--navy);
  color: #fff;
  transform: translateY(-150%);
}

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

.site-header,
main,
footer {
  width: min(calc(100% - 40px), var(--max-width));
  margin-inline: auto;
}

.site-header {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}

.wordmark {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--navy);
  font-weight: 700;
  text-decoration: none;
}

.wordmark small {
  padding-left: 0.65rem;
  border-left: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 500;
}

.wordmark-mark {
  width: 20px;
  height: 20px;
  display: inline-block;
  border: 5px solid var(--navy);
  border-top-color: var(--blue);
  border-radius: 50%;
}

nav {
  display: flex;
  gap: 1.75rem;
}

nav a {
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
}

nav a:hover,
nav a:focus-visible {
  color: var(--blue);
}

.hero {
  padding: 5.5rem 0 4.5rem;
  text-align: center;
}

.hero-copy {
  max-width: 1040px;
  margin-inline: auto;
}

.hero-video-intro {
  width: 100%;
  max-width: 100%;
  margin: 3.5rem auto 0;
  color: var(--muted);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1rem;
  line-height: 1.6;
  text-align: justify;
  text-justify: inter-word;
}

.hero-video-intro strong {
  color: var(--navy);
  font-weight: 600;
}

.hero-video {
  width: 100%;
  max-width: 100%;
  margin: 1.4rem auto 0;
  overflow: hidden;
  border: 1px solid #a9c4dc;
  border-radius: 6px;
  background: #fff;
}

.hero-video video {
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  display: block;
  background: #0b111a;
  object-fit: contain;
}

.hero-video figcaption {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  padding: 0.85rem 1.1rem;
  border-top: 1px solid var(--line);
  text-align: left;
}

.hero-video figcaption strong {
  color: var(--blue);
  font-size: 0.95rem;
}

.hero-video figcaption span {
  color: var(--muted);
  font-size: 0.78rem;
}

.eyebrow {
  margin: 0 0 1.25rem;
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: break-word;
}

h1 {
  margin: 0;
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(2.55rem, 5.3vw, 4.7rem);
  font-weight: 600;
  letter-spacing: -0.035em;
  line-height: 1.08;
}

h1 span {
  display: block;
  max-width: 900px;
  margin: 0.45rem auto 0;
  color: #344c66;
  font-size: 0.56em;
  font-weight: 400;
  letter-spacing: -0.015em;
  line-height: 1.25;
}

.lede {
  max-width: 750px;
  margin: 1.7rem auto 0;
  color: var(--muted);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.2rem;
  text-align: justify;
  text-justify: inter-word;
}

.authors {
  margin-top: 2rem;
}

.author-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.25rem 1.4rem;
}

.author-list a,
.author-list > span {
  color: var(--blue);
  font-size: 1.02rem;
  font-weight: 600;
  text-decoration: none;
}

.author-list > span {
  color: var(--navy);
}

.author-list a:hover {
  text-decoration: underline;
  text-underline-offset: 0.2rem;
}

.author-list sup,
.affiliations sup {
  margin-left: 0.12rem;
  font-size: 0.65em;
  font-weight: 600;
}

.affiliations {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.15rem 1.25rem;
  max-width: 900px;
  margin: 0.45rem auto 0;
}

.affiliations p {
  margin: 0;
  color: var(--muted);
  font-size: 0.82rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  margin-top: 1.8rem;
}

.button {
  min-height: 43px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 1.15rem;
  border: 1px solid var(--blue);
  border-radius: 4px;
  color: var(--blue);
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
}

.button:hover {
  background: var(--blue-light);
}

.button-primary {
  background: var(--blue);
  color: #fff;
}

.button-primary:hover {
  background: var(--navy);
  border-color: var(--navy);
}

.hero-visual {
  display: grid;
  grid-template-columns: 1fr 0.42fr 1fr 0.42fr 1fr;
  gap: 0.75rem;
  align-items: center;
  margin-top: 4rem;
  padding: 2rem;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  text-align: left;
}

.diagram-column {
  display: grid;
  gap: 0.7rem;
}

.diagram-column > p {
  margin: 0 0 0.1rem;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-align: center;
  text-transform: uppercase;
}

.node {
  min-height: 88px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 1rem 1.1rem;
  border: 1px solid #b9c9d8;
  border-radius: 4px;
  background: #fff;
}

.node span {
  display: block;
  margin-bottom: 0.2rem;
  color: var(--muted);
  font-size: 0.72rem;
}

.node strong {
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1rem;
  line-height: 1.3;
}

.node-primary {
  min-height: 176px;
  border: 2px solid var(--blue);
  background: var(--blue-light);
  text-align: center;
}

.diagram-arrow {
  color: var(--muted);
  text-align: center;
}

.diagram-arrow span {
  display: block;
  font-size: 0.65rem;
  line-height: 1.2;
}

.diagram-arrow b {
  display: block;
  color: var(--blue);
  font-size: 1.8rem;
  font-weight: 400;
}

.figure-caption {
  margin: 0.7rem 0 0;
  color: var(--muted);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 0.86rem;
  text-align: left;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin-bottom: 2rem;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: #fff;
}

.stats div {
  padding: 1.25rem 1.5rem;
  border-right: 1px solid var(--line);
  text-align: center;
}

.stats div:last-child {
  border-right: 0;
}

.stats strong,
.stats span {
  display: block;
}

.stats strong {
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.75rem;
  line-height: 1.2;
}

.stats span {
  margin-top: 0.25rem;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.045em;
  text-transform: uppercase;
}

.section {
  display: grid;
  grid-template-columns: 130px minmax(0, 1fr);
  gap: 2.5rem;
  padding: 5.5rem 0;
  border-bottom: 1px solid var(--line);
}

.section-label {
  padding-top: 0.35rem;
}

.section-label span {
  color: var(--blue);
  font-size: 0.72rem;
  font-weight: 700;
}

.section-label p {
  margin: 0.2rem 0 0;
  color: var(--muted);
  font-size: 0.77rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.display-copy,
.section-heading h2 {
  margin: 0;
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.15;
}

.body-copy {
  max-width: 820px;
  margin: 1.4rem 0 0;
  color: #354254;
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.08rem;
  line-height: 1.85;
  text-align: justify;
  text-justify: inter-word;
}

.method {
  color: var(--ink);
}

.section-heading {
  display: grid;
  grid-template-columns: 1fr minmax(250px, 0.65fr);
  gap: 3rem;
  align-items: end;
  margin-bottom: 2.2rem;
}

.section-heading p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.method-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--line);
  border-radius: 5px;
  overflow: hidden;
}

.method-grid article {
  min-height: 250px;
  padding: 1.6rem;
  border-right: 1px solid var(--line);
  background: #fff;
}

.method-grid article:last-child {
  border-right: 0;
}

.card-number {
  display: inline-grid;
  width: 28px;
  height: 28px;
  place-items: center;
  border-radius: 50%;
  background: var(--blue-light);
  color: var(--blue);
  font-size: 0.7rem;
  font-weight: 700;
}

.method-grid h3 {
  margin: 1.2rem 0 0.65rem;
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.28rem;
  font-weight: 600;
}

.method-grid p {
  margin: 0;
  color: var(--muted);
  font-size: 0.94rem;
}

.method-framework {
  margin: 2rem 0 0;
}

.method-framework a {
  display: block;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: #fff;
}

.method-framework a:hover {
  border-color: #a9c4dc;
}

.method-framework img {
  width: 100%;
  height: auto;
  display: block;
}

.method-framework figcaption {
  margin-top: 0.7rem;
  color: var(--muted);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 0.86rem;
}

.method-framework figcaption strong {
  color: var(--ink);
  font-weight: 600;
}

.result-panel {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  min-height: 380px;
  border: 1px solid var(--line);
  border-radius: 5px;
  overflow: hidden;
  background: #fff;
}

.result-figure {
  display: grid;
  grid-template-rows: auto 1fr auto auto;
  margin: 0;
  padding: 2rem 2rem 1.4rem;
  border-right: 1px solid var(--line);
  background: var(--surface);
}

.chart-legend {
  display: flex;
  justify-content: flex-end;
  gap: 1rem;
  color: var(--muted);
  font-size: 0.72rem;
}

.chart-legend span {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.chart-legend i {
  width: 10px;
  height: 10px;
  display: inline-block;
}

.key-baseline {
  background: #aab5c0;
}

.key-ours {
  background: var(--blue);
}

.result-chart {
  display: grid;
  grid-template-columns: repeat(8, minmax(0, 1fr));
  gap: 0.5rem;
  align-items: end;
  min-height: 240px;
  padding: 1.3rem 1.5rem 0;
  border-bottom: 1px solid #aeb9c5;
  background:
    linear-gradient(var(--line) 1px, transparent 1px) 0 0 / 100% 25%;
}

.result-chart i {
  position: relative;
  width: 100%;
  height: var(--height);
  display: block;
  background: var(--blue);
}

.result-chart i::after {
  content: attr(data-value);
  position: absolute;
  bottom: calc(100% + 0.3rem);
  left: 50%;
  color: var(--ink);
  font: 700 0.72rem "Source Sans 3", Arial, sans-serif;
  line-height: 1;
  transform: translateX(-50%);
}

.result-chart i.baseline {
  background: #aab5c0;
}

.chart-labels {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 0.55rem 0.5rem 0;
  color: var(--ink);
  font-size: 0.76rem;
  font-weight: 600;
  text-align: center;
}

.result-figure figcaption {
  margin-top: 0.6rem;
  color: var(--muted);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 0.77rem;
  text-align: center;
}

.result-panel > div:last-child {
  align-self: center;
  padding: 2.5rem;
}

.result-panel h3 {
  margin: 0;
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.25;
}

.result-panel p:last-child {
  margin: 1rem 0 0;
  color: var(--muted);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-top: 1rem;
}

.metrics div {
  padding: 1.25rem 1.4rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
}

.metrics strong,
.metrics span {
  display: block;
}

.metrics strong {
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.55rem;
}

.metrics span {
  margin-top: 0.15rem;
  color: var(--muted);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.evidence-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-top: 1rem;
}

.evidence-grid article {
  padding: 1.6rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
}

.evidence-grid .eyebrow {
  margin-bottom: 0.55rem;
}

.evidence-grid h3 {
  margin: 0;
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.25rem;
  font-weight: 600;
}

.evidence-grid article > p:last-child {
  margin: 0.75rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.video-phase + .video-phase {
  margin-top: 4.5rem;
  padding-top: 3rem;
  border-top: 1px solid var(--line);
}

.video-phase-heading {
  max-width: 720px;
  margin-bottom: 2rem;
}

.video-phase-heading .eyebrow {
  margin-bottom: 0.35rem;
}

.video-phase-heading h3 {
  margin: 0;
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.8rem;
  font-weight: 600;
}

.video-phase-heading > p:last-child {
  margin: 0.45rem 0 0;
  color: var(--muted);
  font-size: 0.94rem;
}

.video-task + .video-task {
  margin-top: 3rem;
}

.video-task-heading {
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
  align-items: baseline;
  margin-bottom: 1rem;
}

.video-task-heading h4,
.video-task-heading p {
  margin: 0;
}

.video-task-heading h4 {
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.35rem;
  font-weight: 600;
}

.video-task-heading p {
  color: var(--muted);
  font-size: 0.78rem;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.video-grid-single {
  grid-template-columns: minmax(0, 1fr);
}

.video-grid-single .video-card video {
  aspect-ratio: 16 / 9;
}

.video-card {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: #fff;
}

.video-card video {
  width: 100%;
  aspect-ratio: 4 / 3;
  display: block;
  background: #0b111a;
  object-fit: contain;
}

.video-card figcaption {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  padding: 0.75rem 0.9rem;
  border-top: 1px solid var(--line);
}

.video-card figcaption strong {
  color: var(--ink);
  font-size: 0.86rem;
}

.video-card figcaption span {
  color: var(--muted);
  font-size: 0.72rem;
}

.video-card-ours {
  border-color: #a9c4dc;
}

.video-card-ours figcaption strong {
  color: var(--blue);
}

.resource-list {
  border-top: 1px solid var(--line);
}

.resource-list a {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 2rem;
  align-items: center;
  padding: 1.15rem 0;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  text-decoration: none;
}

.resource-list a:hover span {
  color: var(--blue);
}

.resource-list span {
  color: var(--navy);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.05rem;
  font-weight: 600;
}

.resource-list small,
.resource-list b {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 500;
}

.citation {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2rem;
  align-items: center;
  margin-top: 3rem;
  padding: 1.5rem;
  border-left: 4px solid var(--blue);
  background: var(--surface);
}

.citation .eyebrow {
  margin-bottom: 0.35rem;
}

.citation h3 {
  margin: 0;
  color: var(--ink);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1rem;
  font-weight: 400;
}

.citation button {
  padding: 0.55rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: 3px;
  background: #fff;
  color: #9aa4ae;
  font: 600 0.72rem "Source Sans 3", Arial, sans-serif;
}

footer {
  display: flex;
  justify-content: space-between;
  padding: 2rem 0 4rem;
  color: var(--muted);
  font-size: 0.78rem;
}

footer p {
  margin: 0;
}

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

  .diagram-arrow {
    transform: none;
  }

  .diagram-arrow b {
    transform: rotate(90deg);
  }

  .node-primary {
    min-height: 110px;
  }

  .section {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }

  .section-heading {
    grid-template-columns: 1fr;
    gap: 0.8rem;
  }

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

  .method-grid article {
    min-height: 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .method-grid article:last-child {
    border-bottom: 0;
  }

  .result-panel {
    grid-template-columns: 1fr;
  }

  .result-figure {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .metrics {
    grid-template-columns: repeat(2, 1fr);
  }

  .video-task-heading {
    display: block;
  }

  .video-task-heading p {
    margin-top: 0.25rem;
  }
}

@media (max-width: 650px) {
  body {
    font-size: 16px;
  }

  .site-header,
  main,
  footer {
    width: min(calc(100% - 30px), var(--max-width));
  }

  .site-header {
    min-height: 66px;
  }

  nav,
  .wordmark small {
    display: none;
  }

  .hero {
    padding: 3.8rem 0 3rem;
  }

  h1 {
    font-size: 2.45rem;
  }

  h1 span {
    font-size: 0.58em;
  }

  .lede {
    font-size: 1.05rem;
  }

  .author-list {
    gap: 0.15rem 0.85rem;
  }

  .hero-video-intro {
    margin-top: 2.5rem;
    font-size: 0.95rem;
  }

  .hero-video {
    margin-top: 1.1rem;
  }

  .hero-video figcaption {
    display: block;
  }

  .hero-visual {
    margin-top: 3rem;
    padding: 1rem;
  }

  .stats,
  .metrics,
  .evidence-grid {
    grid-template-columns: 1fr;
  }

  .stats div {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .stats div:last-child {
    border-bottom: 0;
  }

  .section {
    padding: 4rem 0;
  }

  .body-copy {
    font-size: 1rem;
    text-align: left;
  }

  .result-figure {
    padding: 1.25rem 1rem;
  }

  .result-chart {
    min-height: 210px;
    padding-inline: 0.75rem;
  }

  .result-panel > div:last-child {
    padding: 1.75rem 1.25rem;
  }

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

  .resource-list a {
    grid-template-columns: 1fr auto;
  }

  .resource-list small {
    display: none;
  }

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

  footer {
    flex-direction: column;
    gap: 0.5rem;
  }
}

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