:root {
  color-scheme: dark;
  --bg: #071019;
  --surface: #0d1a25;
  --surface-2: #112332;
  --line: #213747;
  --text: #f1f7f9;
  --muted: #91a8b4;
  --accent: #53e3bd;
  --accent-2: #73a8ff;
  --danger: #ff8d72;
  --truth: #718896;
  --radius: 18px;
  --shadow: 0 18px 55px rgba(0, 0, 0, 0.24);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at 80% -10%, rgba(83, 227, 189, 0.12), transparent 34rem),
    radial-gradient(circle at 10% 24%, rgba(115, 168, 255, 0.08), transparent 28rem),
    var(--bg);
  color: var(--text);
}

a {
  color: inherit;
}

.site-header,
main,
footer {
  width: min(1180px, calc(100% - 40px));
  margin-inline: auto;
}

.site-header {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid rgba(145, 168, 180, 0.16);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  text-decoration: none;
  letter-spacing: -0.02em;
}

.brand-mark {
  width: 23px;
  height: 23px;
  border-radius: 50%;
  border: 2px solid var(--accent);
  position: relative;
  box-shadow: 0 0 24px rgba(83, 227, 189, 0.4);
}

.brand-mark::before,
.brand-mark::after {
  content: "";
  position: absolute;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-2);
}

.brand-mark::before {
  left: -5px;
  top: 6px;
}

.brand-mark::after {
  right: -5px;
  bottom: 4px;
}

nav {
  display: flex;
  align-items: center;
  gap: 24px;
}

nav a,
.text-link,
footer a {
  color: var(--muted);
  text-decoration: none;
}

nav a:hover,
.text-link:hover,
footer a:hover {
  color: var(--text);
}

.hero {
  padding: 92px 0 68px;
  max-width: 920px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 22px;
  font-size: clamp(2.45rem, 6vw, 5.5rem);
  line-height: 0.98;
  letter-spacing: -0.055em;
  max-width: 1000px;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(1.75rem, 3vw, 2.55rem);
  letter-spacing: -0.035em;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.35rem;
}

.hero-copy {
  max-width: 760px;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.28rem);
  line-height: 1.65;
}

.formula {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(13, 26, 37, 0.68);
  color: var(--muted);
  font-size: 0.9rem;
}

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

.section {
  padding: 72px 0;
  border-top: 1px solid rgba(145, 168, 180, 0.16);
}

.section-heading {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 20px;
  margin-bottom: 30px;
}

.simulation-actions {
  display: flex;
  gap: 10px;
}

.button {
  min-height: 42px;
  border-radius: 11px;
  padding: 0 16px;
  border: 1px solid var(--line);
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.button.primary {
  color: #052218;
  background: var(--accent);
  border-color: var(--accent);
}

.button.secondary {
  color: var(--text);
  background: var(--surface);
}

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

.button:focus-visible,
input:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(115, 168, 255, 0.72);
  outline-offset: 3px;
}

.simulation-layout {
  display: grid;
  grid-template-columns: minmax(230px, 285px) minmax(0, 1fr);
  gap: 20px;
}

.controls,
.visual-panel,
.metrics article,
.eda-stat,
.chart-card {
  border: 1px solid var(--line);
  background: linear-gradient(145deg, rgba(17, 35, 50, 0.96), rgba(10, 23, 33, 0.96));
  box-shadow: var(--shadow);
}

.controls,
.visual-panel,
.chart-card {
  border-radius: var(--radius);
}

.controls {
  padding: 20px;
  display: grid;
  gap: 18px;
  align-content: start;
}

.controls label {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 0.83rem;
}

.controls label span {
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

output {
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.visual-panel {
  padding: 14px;
  min-width: 0;
}

.frame-toolbar {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 0 4px 12px;
  color: var(--muted);
  font-size: 0.85rem;
}

.frame-toolbar strong {
  color: var(--text);
}

.frame-toolbar input {
  flex: 1;
}

#tracking-canvas {
  display: block;
  width: 100%;
  height: auto;
  min-height: 310px;
  border-radius: 12px;
  background:
    radial-gradient(circle at center, rgba(115, 168, 255, 0.06), transparent 60%),
    #08131c;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  padding: 12px 4px 2px;
  color: var(--muted);
  font-size: 0.78rem;
}

.legend span {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.legend-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  display: inline-block;
}

.legend-dot.truth {
  background: var(--truth);
}

.legend-dot.matched {
  background: var(--accent);
}

.legend-dot.false {
  background: var(--danger);
}

.legend-line {
  width: 20px;
  border-top: 2px solid var(--accent-2);
}

.metrics,
.eda-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-top: 16px;
}

.metrics article,
.eda-stat {
  padding: 18px;
  border-radius: 14px;
}

.metrics span,
.eda-stat span {
  display: block;
  min-height: 36px;
  color: var(--muted);
  font-size: 0.78rem;
  letter-spacing: 0.02em;
}

.metrics strong,
.eda-stat strong {
  display: block;
  margin: 2px 0 8px;
  font-size: clamp(1.55rem, 3vw, 2.25rem);
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
}

.metrics small,
.eda-stat p {
  color: var(--muted);
  line-height: 1.45;
}

.eda-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 0;
}

.eda-stat p {
  margin: 0;
  font-size: 0.88rem;
}

.insight {
  margin: 16px 0 0;
  padding: 12px 14px;
  border-left: 3px solid var(--accent);
  color: var(--muted);
  background: rgba(83, 227, 189, 0.055);
  line-height: 1.55;
}

.chart-card {
  margin-top: 18px;
  padding: 26px;
  display: grid;
  grid-template-columns: minmax(220px, 0.65fr) minmax(0, 1.35fr);
  gap: 24px;
  align-items: center;
}

.chart-copy p:last-child {
  color: var(--muted);
  line-height: 1.55;
}

.intensity-chart {
  width: 100%;
  min-width: 0;
}

.intensity-chart line {
  stroke: var(--line);
  stroke-width: 2;
}

.intensity-chart .bars rect {
  fill: var(--accent-2);
  opacity: 0.72;
}

.intensity-chart text {
  fill: var(--muted);
  font-size: 13px;
  text-anchor: middle;
}

.intensity-chart .values text {
  fill: var(--text);
}

.hypothesis-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.hypothesis-list li {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 14px;
  padding: 22px;
  border-top: 1px solid var(--line);
}

.hypothesis-list li > span {
  color: var(--accent);
  font-weight: 800;
}

.hypothesis-list strong {
  display: block;
  margin-bottom: 7px;
}

.hypothesis-list p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

footer {
  min-height: 100px;
  padding: 30px 0;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
  border-top: 1px solid rgba(145, 168, 180, 0.16);
  color: var(--muted);
  font-size: 0.86rem;
}

@media (max-width: 900px) {
  .simulation-layout,
  .chart-card {
    grid-template-columns: 1fr;
  }

  .controls {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .metrics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .site-header,
  main,
  footer {
    width: min(100% - 24px, 1180px);
  }

  .site-header {
    align-items: flex-start;
    padding: 18px 0;
  }

  nav {
    display: none;
  }

  .hero {
    padding: 62px 0 48px;
  }

  .section {
    padding: 54px 0;
  }

  .section-heading {
    align-items: flex-start;
    flex-direction: column;
  }

  .simulation-actions {
    width: 100%;
  }

  .simulation-actions .button {
    flex: 1;
  }

  .controls,
  .metrics,
  .eda-grid,
  .hypothesis-list {
    grid-template-columns: 1fr;
  }

  .metrics span,
  .eda-stat span {
    min-height: auto;
  }

  #tracking-canvas {
    min-height: 260px;
  }

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

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}