:root {
  color-scheme: dark;
  --bg: #07110f;
  --panel: #0c1a17;
  --panel-strong: #11231f;
  --ink: #f3f8f5;
  --muted: #9eb3aa;
  --line: #284039;
  --mint: #62f5bd;
  --mint-soft: rgba(98, 245, 189, 0.12);
  --amber: #f7c96b;
  --red: #ff8b7e;
  --radius: 20px;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  background: var(--bg);
  color: var(--ink);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 80% 4%, rgba(98, 245, 189, 0.08), transparent 25rem),
    linear-gradient(180deg, #07110f 0%, #081512 100%);
}

a {
  color: inherit;
}

.site-header,
main,
footer {
  width: min(1120px, calc(100% - 40px));
  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: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  font-size: 14px;
  font-weight: 680;
}

.wordmark-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 34px;
  border: 1px solid var(--mint);
  border-radius: 10px;
  color: var(--mint);
  font-size: 12px;
  letter-spacing: 0.08em;
}

nav {
  display: flex;
  gap: 22px;
}

nav a,
footer a {
  color: var(--muted);
  text-decoration-color: transparent;
  text-underline-offset: 4px;
}

nav a:hover,
footer a:hover {
  color: var(--ink);
  text-decoration-color: var(--mint);
}

.hero {
  padding: 110px 0 84px;
  max-width: 910px;
}

.eyebrow,
.stage-kind {
  margin: 0 0 14px;
  color: var(--mint);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  text-wrap: pretty;
}

h1 {
  max-width: 870px;
  margin: 0;
  font-size: clamp(48px, 8vw, 92px);
  line-height: 0.98;
  letter-spacing: -0.055em;
}

.hero-copy {
  max-width: 640px;
  margin: 30px 0;
  color: var(--muted);
  font-size: clamp(18px, 2.4vw, 25px);
  line-height: 1.5;
}

.evidence-path {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 13px;
}

.evidence-path span:nth-child(odd) {
  padding: 8px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--ink);
}

.demo-section {
  padding: 44px 0 90px;
}

.section-heading {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 32px;
  margin-bottom: 24px;
}

h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 48px);
  letter-spacing: -0.04em;
}

.privacy-note {
  white-space: nowrap;
  color: var(--muted);
  font-size: 12px;
}

.lab {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: 0 32px 90px rgba(0, 0, 0, 0.28);
}

.network-stage {
  min-height: 240px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
  background:
    linear-gradient(rgba(98, 245, 189, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(98, 245, 189, 0.025) 1px, transparent 1px),
    var(--panel-strong);
  background-size: 28px 28px;
}

.node {
  position: relative;
  width: 180px;
  padding: 22px;
  border: 1px solid #36544b;
  border-radius: 16px;
  background: #0a1513;
}

.node strong,
.node small {
  display: block;
}

.node strong {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

.node small {
  margin-top: 8px;
  color: var(--muted);
}

.node-light {
  position: absolute;
  top: 18px;
  right: 18px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 18px var(--mint);
}

.cable {
  width: min(25vw, 240px);
  height: 30px;
  display: flex;
  align-items: center;
}

.cable span {
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--mint), #36544b, var(--mint));
}

.prompt-panel {
  padding: clamp(26px, 5vw, 54px);
  border-top: 1px solid var(--line);
}

.progress-row {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-bottom: 32px;
  color: var(--muted);
  font-size: 12px;
}

.progress-track {
  flex: 1;
  height: 3px;
  overflow: hidden;
  border-radius: 99px;
  background: var(--line);
}

#progress-bar {
  display: block;
  width: 25%;
  height: 100%;
  background: var(--mint);
  transition: width 240ms ease;
}

.prompt-panel h3 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(24px, 3vw, 38px);
  line-height: 1.18;
  letter-spacing: -0.025em;
}

.context {
  max-width: 780px;
  margin: 18px 0 0;
  color: var(--muted);
  line-height: 1.65;
}

.choices {
  display: grid;
  gap: 12px;
  margin-top: 28px;
}

.choice,
.next-button {
  border: 1px solid var(--line);
  border-radius: 12px;
  color: var(--ink);
  font: inherit;
  cursor: pointer;
}

.choice {
  padding: 16px 18px;
  background: transparent;
  text-align: left;
}

.choice:hover,
.choice:focus-visible {
  border-color: var(--mint);
  background: var(--mint-soft);
  outline: none;
}

.choice[disabled] {
  cursor: default;
  opacity: 0.55;
}

.choice.selected {
  border-color: var(--mint);
  opacity: 1;
}

.feedback {
  margin-top: 22px;
  padding: 18px;
  border-left: 3px solid var(--mint);
  background: var(--mint-soft);
  color: #d9eee6;
  line-height: 1.55;
}

.feedback[data-result="revise"] {
  border-color: var(--amber);
  background: rgba(247, 201, 107, 0.09);
}

.next-button {
  margin-top: 22px;
  padding: 14px 18px;
  background: var(--mint);
  color: #05100d;
  font-weight: 760;
}

.next-button:hover,
.next-button:focus-visible {
  filter: brightness(1.08);
  outline: 3px solid rgba(98, 245, 189, 0.25);
}

.trace-section {
  grid-template-columns: 0.8fr 1.2fr;
  gap: 60px;
  align-items: start;
  padding: 80px 0;
  border-top: 1px solid var(--line);
}

.trace-section:not([hidden]) {
  display: grid;
}

.trace-section p:not(.eyebrow) {
  color: var(--muted);
  line-height: 1.65;
}

pre {
  overflow: auto;
  margin: 0;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #050c0a;
  color: #c9f4e3;
  font-size: 12px;
  line-height: 1.65;
}

.principles {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  margin: 40px 0 100px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--line);
}

.principles article {
  padding: 34px;
  background: var(--panel);
}

.principles article > span {
  color: var(--mint);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

.principles h2 {
  margin-top: 50px;
  font-size: 24px;
}

.principles p {
  color: var(--muted);
  line-height: 1.6;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 30px 0 48px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}

@media (max-width: 760px) {
  .site-header {
    align-items: flex-start;
    padding: 18px 0;
  }

  .wordmark > span:last-child {
    display: none;
  }

  .hero {
    padding-top: 72px;
  }

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

  .network-stage {
    min-height: 190px;
    padding: 24px 14px;
  }

  .node {
    width: 130px;
    padding: 18px 14px;
  }

  .node-light {
    top: 14px;
    right: 14px;
  }

  .cable {
    width: 42px;
  }

  .trace-section:not([hidden]) {
    grid-template-columns: 1fr;
  }

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

@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto !important;
    transition: none !important;
  }
}