:root {
  --bg: #0b1420;
  --bg-elev: #132033;
  --ink: #eef3f7;
  --muted: #9aafc0;
  --line: rgba(238, 243, 247, 0.12);
  --accent: #f0b429;
  --accent-2: #5eb7d4;
  --accent-soft: rgba(240, 180, 41, 0.16);
  --accent2-soft: rgba(94, 183, 212, 0.16);
  --ok: #5eb7d4;
  --warn: #f0b429;
  --font-display: "Fraunces", Georgia, serif;
  --font-body: "Source Sans 3", "Segoe UI", sans-serif;
  --radius: 16px;
  --max: 1120px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(1100px 640px at 85% -8%, rgba(240, 180, 41, 0.12), transparent 55%),
    radial-gradient(900px 560px at 8% 18%, rgba(94, 183, 212, 0.12), transparent 50%),
    var(--bg);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: inherit;
}

.grain {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 50;
  opacity: 0.04;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  transition: background 0.35s var(--ease), border-color 0.35s var(--ease);
  border-bottom: 1px solid transparent;
}

.nav.is-solid {
  background: rgba(11, 20, 32, 0.82);
  border-bottom-color: var(--line);
  backdrop-filter: blur(14px);
}

.nav-brand {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: 0.06em;
  text-decoration: none;
  font-size: 1.1rem;
  color: var(--accent);
}

.nav-links {
  display: flex;
  gap: 1.2rem;
  flex-wrap: wrap;
}

.nav-links a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 600;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--ink);
}

.hero {
  position: relative;
  min-height: 100vh;
  display: grid;
  align-items: end;
  overflow: hidden;
}

.hero-media {
  position: absolute;
  inset: 0;
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 55% 42%;
  transform: scale(1.03);
}

.hero-veil {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(11, 20, 32, 0.18) 0%, rgba(11, 20, 32, 0.42) 38%, rgba(11, 20, 32, 0.95) 100%),
    linear-gradient(100deg, rgba(11, 20, 32, 0.9) 0%, rgba(11, 20, 32, 0.58) 38%, rgba(11, 20, 32, 0.22) 68%);
}

.hero-copy {
  position: relative;
  z-index: 2;
  max-width: var(--max);
  margin: 0 auto;
  padding: 7rem 1.5rem 3.5rem;
}

.hero-brand {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 8vw, 5.5rem);
  font-weight: 800;
  letter-spacing: 0.04em;
  margin: 0 0 0.4rem;
  color: var(--accent);
  line-height: 0.95;
}

.hero h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.55rem, 3.4vw, 2.35rem);
  line-height: 1.15;
  margin: 0 0 0.85rem;
  max-width: 16ch;
}

.hero-lede {
  max-width: 46ch;
  color: var(--muted);
  margin: 0 0 1.4rem;
  font-size: 1.05rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.hero-meta {
  margin: 1.4rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.hero-meta a {
  color: var(--accent-2);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.72rem 1.15rem;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 700;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s var(--ease), background 0.2s, border-color 0.2s;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent);
  color: #1a1408;
}

.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--ink);
}

.btn-ghost:hover {
  border-color: var(--accent-2);
}

.section {
  padding: 5.5rem 0;
}

.section-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-2);
  margin: 0 0 0.7rem;
}

.section h2 {
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.2vw, 2.45rem);
  line-height: 1.15;
  margin: 0 0 1rem;
  max-width: 22ch;
}

.section-lede {
  color: var(--muted);
  max-width: 62ch;
  margin: 0 0 2rem;
}

.why .explain-figure,
.system .explain-figure[data-explain="setup"] {
  margin: 1.5rem 0 2.25rem;
}

.bg-layout {
  display: grid;
  grid-template-columns: 1.4fr 0.9fr;
  gap: 2rem;
  align-items: start;
}

.bg-lead {
  font-size: 1.15rem;
  color: var(--ink);
}

.bg-copy p {
  color: var(--muted);
}

.bg-copy em {
  color: var(--accent);
  font-style: normal;
  font-weight: 700;
}

.bg-aside {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem;
  display: grid;
  gap: 1rem;
}

.bg-stat strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.8rem;
  color: var(--accent);
  line-height: 1.1;
}

.bg-stat span {
  color: var(--muted);
  font-size: 0.92rem;
}

.bg-aside-note {
  margin: 0;
  padding-top: 0.5rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
}

.system-layout {
  display: grid;
  grid-template-columns: 1.15fr 0.95fr;
  gap: 1.5rem;
  align-items: start;
}

.system-stage {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  min-height: 320px;
}

.system-stage img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  background: #ffffff;
  padding: 0.75rem;
}

.system-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 1rem;
}

.sys-tab,
.explain-chip,
.compare-chip,
.demo-btn {
  font: inherit;
  cursor: pointer;
}

.sys-tab,
.explain-chip {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  border-radius: 999px;
  padding: 0.4rem 0.8rem;
  font-size: 0.85rem;
  font-weight: 600;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}

.sys-tab.is-active,
.explain-chip.is-active {
  background: var(--accent-soft);
  border-color: rgba(240, 180, 41, 0.45);
  color: var(--ink);
}

.system-card {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.2rem 1.3rem;
}

.system-kicker {
  margin: 0;
  color: var(--accent-2);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 700;
}

.system-card h3 {
  font-family: var(--font-display);
  margin: 0.35rem 0 0.55rem;
}

.system-card p {
  margin: 0;
  color: var(--muted);
}

.system-caption,
.stage-caption,
.chart-note,
figcaption {
  color: var(--muted);
  font-size: 0.88rem;
}

.system-caption {
  margin: 0.9rem 0 0;
}

.spec-strip {
  margin-top: 2rem;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.75rem;
}

.spec-strip div {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.9rem;
}

.spec-strip strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--accent-2);
}

.spec-strip span {
  color: var(--muted);
  font-size: 0.82rem;
}

.explain-figure {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 1.25rem;
  margin-bottom: 1.75rem;
  align-items: start;
}

.detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.detail-grid .explain-figure {
  grid-template-columns: 1fr;
  margin-bottom: 0;
}

.figure-panel {
  margin: 0;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.figure-zoom {
  position: relative;
  display: block;
  width: 100%;
  padding: 0.75rem;
  border: 0;
  background: #ffffff;
  cursor: zoom-in;
}

.figure-zoom img {
  width: 100%;
  background: #ffffff;
}

.zoom-hint {
  position: absolute;
  right: 0.7rem;
  bottom: 0.7rem;
  background: rgba(11, 20, 32, 0.75);
  border: 1px solid var(--line);
  color: var(--ink);
  font-size: 0.75rem;
  padding: 0.25rem 0.55rem;
  border-radius: 999px;
}

.figure-panel figcaption {
  padding: 0.85rem 1rem 1rem;
  background: var(--bg-elev);
  border-top: 1px solid var(--line);
}

.figure-panel figcaption strong {
  display: block;
  color: var(--ink);
  font-weight: 700;
}

.figure-panel figcaption span {
  display: block;
  margin-top: 0.2rem;
}

.explain-box {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
}

.explain-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.85rem;
}

.explain-text {
  margin: 0;
  color: var(--muted);
}

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

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.feature {
  background: linear-gradient(180deg, rgba(94, 183, 212, 0.08), transparent 55%), var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.2rem;
}

.feature-num {
  color: var(--accent);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 0.95rem;
}

.feature h3 {
  margin: 0.4rem 0 0.45rem;
  font-family: var(--font-display);
}

.feature p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.85rem;
  margin-bottom: 2rem;
}

.metric {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem;
}

.metric-value {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  font-weight: 800;
  color: var(--accent);
  line-height: 1.1;
}

.metric-label {
  color: var(--muted);
  font-size: 0.88rem;
}

.chart-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.chart-card {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem 1.15rem 0.9rem;
}

.chart-card-wide {
  grid-column: 1 / -1;
}

.chart-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: baseline;
  margin-bottom: 0.6rem;
}

.chart-head strong {
  font-family: var(--font-display);
  font-size: 1.05rem;
}

.chart-head span {
  color: var(--muted);
  font-size: 0.82rem;
}

.chart-wrap {
  position: relative;
  height: 240px;
}

.chart-wrap-wide {
  height: 280px;
}

.chart-note {
  margin: 0.55rem 0 0;
}

.figure-explain-block {
  margin: 2.5rem 0 1.25rem;
}

.gallery-title {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 2.4vw, 1.85rem);
  margin: 0 0 0.5rem;
}

.results .explain-figure {
  margin-bottom: 1.75rem;
}

.paper-card {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr;
  gap: 1.5rem;
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.4rem;
  align-items: center;
}

.paper-card h3 {
  font-family: var(--font-display);
  margin: 0 0 0.5rem;
}

.paper-authors,
.paper-venue,
.paper-aff {
  margin: 0.25rem 0;
  color: var(--muted);
}

.paper-actions {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.cite-block {
  margin: 1rem 0 0;
  padding: 1rem 1.1rem;
  background: #081018;
  border: 1px solid var(--line);
  border-radius: 12px;
  color: var(--muted);
  white-space: pre-wrap;
  font-size: 0.88rem;
  overflow-x: auto;
}

.demo-layout {
  display: grid;
  grid-template-columns: 0.9fr 1.2fr;
  gap: 1.2rem;
}

.demo-chapters {
  display: grid;
  gap: 0.65rem;
}

.demo-btn {
  text-align: left;
  border: 1px solid var(--line);
  background: var(--bg-elev);
  color: var(--ink);
  border-radius: 12px;
  padding: 0.9rem 1rem;
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: 0.75rem;
  row-gap: 0.15rem;
  transition: border-color 0.2s, background 0.2s;
}

.demo-btn span {
  grid-row: span 2;
  align-self: center;
  font-family: var(--font-display);
  font-weight: 800;
  color: var(--accent);
}

.demo-btn strong {
  font-size: 0.98rem;
}

.demo-btn em {
  grid-column: 2;
  color: var(--muted);
  font-style: normal;
  font-size: 0.85rem;
}

.demo-btn.is-active {
  border-color: rgba(240, 180, 41, 0.55);
  background: var(--accent-soft);
}

.demo-stage {
  background: #05090f;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  padding: 0.6rem 0.6rem 0.9rem;
}

.demo-stage video {
  width: 100%;
  border-radius: 10px;
  background: #000;
  aspect-ratio: 16 / 9;
}

.footer {
  border-top: 1px solid var(--line);
  padding: 2rem 0 2.5rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer-note {
  margin: 0;
}

.footer p {
  margin: 0;
}

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 60;
  background: rgba(5, 9, 15, 0.92);
  display: grid;
  place-items: center;
  padding: 2rem;
}

.lightbox[hidden] {
  display: none;
}

.lightbox img {
  max-height: 80vh;
  max-width: min(1100px, 100%);
  border-radius: 10px;
  background: #ffffff;
  padding: 0.75rem;
}

.lightbox p {
  color: var(--muted);
  margin: 0.75rem 0 0;
  text-align: center;
}

.lightbox-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  border: 1px solid var(--line);
  background: var(--bg-elev);
  color: var(--ink);
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 999px;
  font-size: 1.4rem;
  cursor: pointer;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

@media (max-width: 960px) {
  .bg-layout,
  .system-layout,
  .explain-figure,
  .detail-grid,
  .feature-grid,
  .metrics,
  .chart-grid,
  .paper-card,
  .demo-layout,
  .spec-strip {
    grid-template-columns: 1fr;
  }

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

  .nav-links {
    gap: 0.7rem;
  }

  .hero h1 {
    max-width: none;
  }
}

@media (max-width: 560px) {
  .metrics {
    grid-template-columns: 1fr;
  }

  .nav-links {
    display: none;
  }
}