:root {
  --bg: #f7f4ef;
  --bg2: #efe8dc;
  --ink: #1c1914;
  --muted: #5c564c;
  --line: #d9d0c2;
  --card: #fffdf8;
  --accent: #0f6b5c;
  --accent2: #c45c26;
  --good: #1f7a3f;
  --shadow: 0 10px 30px rgba(28, 25, 20, 0.06);
  --page-max: 1180px;
  --toc-w: 190px;
  --serif: "Source Serif 4", "Iowan Old Style", "Palatino Linotype", Palatino, serif;
  --sans: "IBM Plex Sans", "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: #fff;
  font-family: var(--sans);
  line-height: 1.7;
  font-size: 18px;
}

a { color: var(--accent); }
img, svg, video { max-width: 100%; height: auto; display: block; }

/* —— Splash —— */
.splash {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  overflow: hidden;
  background: #0a0c0f;
}
.splash-media { position: absolute; inset: 0; z-index: 0; }
.splash-media video {
  width: 100%; height: 100%;
  object-fit: cover; max-width: none;
}
.splash-scrim {
  position: absolute; inset: 0; z-index: 1;
  background:
    radial-gradient(ellipse 75% 60% at 50% 45%, rgba(0,0,0,0.22) 0%, rgba(0,0,0,0.55) 65%, rgba(0,0,0,0.8) 100%),
    linear-gradient(180deg, rgba(0,0,0,0.42) 0%, transparent 35%, transparent 55%, rgba(0,0,0,0.72) 100%);
}
.splash-center {
  position: relative; z-index: 2;
  text-align: center;
  padding: 5rem 1.6rem 4rem;
  max-width: 1280px; width: 100%;
}
.splash-acronym {
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(6.5rem, 18vw, 11rem);
  letter-spacing: -0.05em;
  line-height: 0.9;
  margin: 0 0 1.35rem;
  text-shadow: 0 4px 28px rgba(0,0,0,0.5);
}
.splash-title {
  font-family: var(--sans);
  font-weight: 600;
  font-size: clamp(1.15rem, 2.1vw, 1.5rem);
  line-height: 1.4;
  margin: 0 auto 1.2rem;
  max-width: min(46rem, 96vw);
  color: rgba(255,255,255,0.96);
  text-shadow: 0 1px 12px rgba(0,0,0,0.45);
}
.splash-title br { display: block; }
.splash-title-line2 {
  display: inline-block;
  white-space: nowrap;
}
@media (max-width: 720px) {
  .splash-title {
    font-size: clamp(0.95rem, 3.6vw, 1.2rem);
  }
}
.splash-authors {
  margin: 0 auto 1.25rem;
  font-size: clamp(1.05rem, 1.7vw, 1.25rem);
  color: rgba(255,255,255,0.92);
  line-height: 1.55;
}
.splash-authors a {
  color: #fff; text-decoration: none;
  border-bottom: 1px solid rgba(255,255,255,0.35);
}
.splash-authors a:hover { border-bottom-color: #fff; }
.splash-logos {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1.1rem;
  margin: 0 0 2rem;
}
.splash-logos img {
  height: 72px;
  width: auto;
  object-fit: contain;
  filter: brightness(0) invert(1);
  opacity: 0.92;
}
.splash-logos img.ri-logo {
  height: 64px;
  filter: none;
  background: #fff;
  border-radius: 12px;
  padding: 0.55rem 0.95rem;
}
.splash-actions {
  display: flex; flex-wrap: wrap;
  justify-content: center; gap: 0.55rem;
}
.splash-btn {
  display: inline-flex; align-items: center; gap: 0.35rem;
  padding: 0.48rem 0.95rem;
  border-radius: 999px;
  background: rgba(15, 107, 92, 0.95);
  border: 1px solid rgba(255,255,255,0.18);
  color: #fff; text-decoration: none;
  font-size: 0.82rem; font-weight: 600;
  letter-spacing: 0.03em; text-transform: uppercase;
}
.splash-btn:hover { background: #0c574b; color: #fff; }
.splash-btn.ghost { background: rgba(255,255,255,0.14); }
.splash-btn.ghost:hover { background: rgba(255,255,255,0.24); }
.splash-skip {
  position: absolute; z-index: 3;
  left: 50%; bottom: 1.1rem; transform: translateX(-50%);
  color: rgba(255,255,255,0.7); font-size: 0.82rem; text-decoration: none;
}
.splash-skip:hover { color: #fff; }

/* —— Top nav —— */
.topnav {
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid #e8e8e8;
}
.topnav-inner {
  max-width: var(--page-max);
  margin: 0 auto; padding: 0.7rem 1.2rem;
  display: flex; gap: 0.85rem; flex-wrap: wrap; align-items: center;
}
.brand {
  font-weight: 700; letter-spacing: -0.02em;
  color: var(--ink); text-decoration: none; margin-right: auto;
}
.topnav-links {
  display: flex; gap: 0.75rem; flex-wrap: wrap; align-items: center;
}
.topnav a { text-decoration: none; color: var(--muted); font-size: 0.86rem; }
.topnav a:hover { color: var(--accent); }
@media (min-width: 1100px) {
  .topnav-links { display: none; }
}

/* —— Page shell —— */
.blog-shell { background: #fff; border-top: 1px solid #eee; }
.page-body {
  max-width: var(--page-max);
  margin: 0 auto; padding: 1.5rem 1.2rem 0;
  display: grid;
  grid-template-columns: var(--toc-w) minmax(0, 1fr);
  gap: 1.75rem; align-items: start;
}
.side-toc {
  position: sticky; top: 3.6rem; align-self: start;
  padding: 0.4rem 0 2rem;
  display: flex; flex-direction: column; gap: 0.15rem;
  max-height: calc(100vh - 4.2rem); overflow-y: auto;
}
.side-toc-label {
  font-size: 0.68rem; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--muted); font-weight: 600; margin-bottom: 0.45rem;
}
.side-toc a {
  text-decoration: none; color: var(--muted); font-size: 0.84rem;
  padding: 0.28rem 0.55rem 0.28rem 0.7rem;
  border-left: 2px solid transparent; line-height: 1.35;
}
.side-toc a:hover { color: var(--ink); }
.side-toc a.active {
  color: var(--accent); border-left-color: var(--accent);
  font-weight: 600; background: rgba(15, 107, 92, 0.06);
}
.wrap { margin: 0; padding: 0.4rem 0 4rem; min-width: 0; }
@media (max-width: 1099px) {
  .page-body { grid-template-columns: 1fr; }
  .side-toc { display: none; }
}

section {
  margin: 2.6rem 0; padding-top: 0.35rem;
  scroll-margin-top: 4.2rem;
}
section > h2 {
  font-family: var(--serif);
  font-size: 1.85rem; letter-spacing: -0.02em;
  margin: 0 0 0.8rem;
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.4rem;
}
#experiments > h2 {
  color: var(--accent);
  border-bottom-color: rgba(15, 107, 92, 0.28);
}
h3 {
  font-family: var(--serif);
  font-size: 1.25rem; margin: 1.5rem 0 0.55rem;
}
section > p { font-size: 1.02rem; }

.callout {
  background: #f3ebe0;
  border-left: 4px solid var(--accent2);
  padding: 0.95rem 1.05rem;
  border-radius: 0 10px 10px 0; margin: 1rem 0;
}
.callout.muted { border-left-color: var(--line); background: var(--bg); }
.callout p { margin: 0; }
.callout p + p { margin-top: 0.55rem; }

.figure {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px; padding: 0.85rem;
  box-shadow: var(--shadow); margin: 1.1rem 0 1.4rem;
  text-align: center;
}
.figure-media {
  display: flex;
  justify-content: center;
  align-items: center;
}
.figure video, .figure img {
  width: 100%; border-radius: 8px; background: #0f1216;
  margin-left: auto; margin-right: auto;
}
.figure img.light { background: #fff; }
.figure video.narrow {
  max-width: 420px;
  width: 100%;
}
.figure figcaption {
  margin: 0.7rem auto 0;
  max-width: 42em;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.45;
  text-align: center;
}
.stack { display: grid; gap: 0.9rem; margin: 1.1rem 0 1.4rem; }
.stack .figure { margin: 0; }

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.85rem;
  margin: 1.1rem 0 1.3rem;
}
@media (max-width: 900px) {
  .related-grid { grid-template-columns: 1fr; }
}
.related-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 0.7rem;
  box-shadow: var(--shadow);
  text-align: center;
}
.related-card img {
  width: 100%;
  aspect-ratio: 16 / 11;
  object-fit: cover;
  border-radius: 8px;
  background: #111;
}
.related-card h4 {
  margin: 0.65rem 0 0.2rem;
  font-family: var(--serif);
  font-size: 1.02rem;
}
.related-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.86rem;
  line-height: 1.4;
}

.method-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  margin: 1.1rem 0 1.35rem;
  counter-reset: step;
}
@media (max-width: 800px) {
  .method-steps { grid-template-columns: 1fr; }
}
.method-step {
  position: relative;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1.15rem 1.05rem 1.05rem;
  box-shadow: var(--shadow);
  text-align: left;
}
.method-step::before {
  counter-increment: step;
  content: counter(step);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.7rem; height: 1.7rem;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  margin-bottom: 0.55rem;
}
.method-step h4 {
  margin: 0 0 0.35rem;
  font-family: var(--serif);
  font-size: 1.05rem;
}
.method-step p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.45;
}

.method-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 0.9rem; margin: 1rem 0 1.3rem;
}
@media (max-width: 800px) {
  .method-grid { grid-template-columns: 1fr; }
}
.method-card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: 14px; padding: 1.05rem 1.15rem; box-shadow: var(--shadow);
}
.method-card h4 {
  margin: 0 0 0.45rem; font-family: var(--serif); font-size: 1.05rem;
}
.method-card ul { margin: 0.35rem 0 0; padding-left: 1.15rem; }
.method-card li { margin: 0.25rem 0; }

.method-glossary {
  display: grid;
  gap: 0.45rem;
  margin: 0.8rem 0 1.2rem;
  padding: 0.9rem 1rem;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 12px;
  font-size: 0.92rem;
}
.method-glossary div {
  display: grid;
  grid-template-columns: 9.5rem 1fr;
  gap: 0.6rem;
}
@media (max-width: 700px) {
  .method-glossary div { grid-template-columns: 1fr; gap: 0.15rem; }
}
.method-glossary strong {
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.84rem;
}
.method-glossary span { color: var(--muted); }

/* labeled 2×2 map figure — paper order: Warehouse, Random, Tilt, Maze */
.maps-frame {
  position: relative;
  border-radius: 8px; overflow: hidden;
  background: #fff;
}
.maps-frame > img { width: 100%; display: block; }
.maps-labels {
  position: absolute; inset: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr;
  pointer-events: none;
}
.maps-labels span {
  justify-self: start; align-self: start;
  margin: 0.55rem;
  background: rgba(28, 25, 20, 0.78);
  color: #fff;
  font-size: 0.78rem; font-weight: 600;
  letter-spacing: 0.03em;
  padding: 0.22rem 0.55rem;
  border-radius: 6px;
}

.chart-panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1rem 1.1rem 1.15rem;
  box-shadow: var(--shadow);
  margin: 1rem 0 1.2rem;
}
.chart-panel .chart-head {
  display: flex; flex-wrap: wrap;
  align-items: baseline; justify-content: space-between;
  gap: 0.5rem 1rem; margin-bottom: 0.65rem;
}
.chart-panel h3 { margin: 0; font-size: 1.1rem; }
.chart-hint { font-size: 0.82rem; color: var(--muted); }
.chart-box { position: relative; height: 380px; }
.chart-box.tall { height: 420px; }
.chart-box.scatter { height: 400px; }
.map-pills {
  display: flex; flex-wrap: wrap; gap: 0.35rem;
  margin: 0.2rem 0 0.8rem;
}
.map-pill {
  border: 1px solid var(--line); background: #fff;
  color: var(--muted); border-radius: 999px;
  padding: 0.22rem 0.7rem; font: inherit; font-size: 0.8rem;
  cursor: pointer;
}
.map-pill.active {
  background: var(--accent); border-color: var(--accent);
  color: #fff; font-weight: 600;
}

details.paper-fig {
  margin: 0.4rem 0 1.4rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg);
  padding: 0.55rem 0.9rem;
}
details.paper-fig summary {
  cursor: pointer; color: var(--muted); font-size: 0.9rem;
}
details.paper-fig img {
  margin-top: 0.7rem; border-radius: 8px; background: #fff;
}

.cite-card {
  background: var(--bg); border: 1px solid var(--line);
  border-radius: 14px; padding: 1.1rem 1.15rem 1rem; margin-top: 0.5rem;
}
pre.bibtex {
  background: #fff; border: 1px solid var(--line);
  border-radius: 10px; padding: 0.9rem 1rem;
  overflow-x: auto; font-family: var(--mono);
  font-size: 0.8rem; line-height: 1.55; margin: 0.55rem 0 0;
}
.bib-tools { display: flex; justify-content: flex-end; margin-top: 0.55rem; }
.bib-tools button {
  border: 1px solid var(--line); background: #fff; border-radius: 7px;
  padding: 0.35rem 0.75rem; font: inherit; font-size: 0.84rem;
  cursor: pointer; color: var(--muted);
}
.bib-tools button:hover { color: var(--accent); border-color: var(--accent); }

.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.5rem 1.2rem 2.4rem;
  text-align: center; color: var(--muted);
  font-size: 0.9rem; background: var(--bg);
}
.site-footer a { color: var(--accent); text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }
.site-footer .foot-links {
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 0.75rem 1.2rem; margin-bottom: 0.65rem;
}
.site-footer .foot-logo {
  height: 36px; width: auto; margin: 0 auto 0.75rem;
  opacity: 0.85;
}