:root {
  --paper: #f4f6f3;
  --paper-deep: #e7ebe6;
  --white: #fcfdfb;
  --ink: #16223a;
  --ink-soft: #526079;
  --line: #ced6d1;
  --console: #11192b;
  --console-soft: #1b2741;
  --voice: #4d6bfe;
  --voice-soft: #dce3ff;
  --director: #f06b5e;
  --director-soft: #fbe0dc;
  --mint: #48c6a5;
  --amber: #f3b44e;
  --rail-width: 264px;
  --display: ui-rounded, "SF Pro Rounded", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --body: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, "SFMono-Regular", "Cascadia Mono", "Roboto Mono", monospace;
  --shadow: 0 26px 70px rgba(22, 34, 58, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  background: var(--paper);
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: clip;
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(22, 34, 58, 0.022) 1px, transparent 1px) 0 0 / 88px 88px,
    var(--paper);
  font-family: var(--body);
  font-size: 16px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  color: inherit;
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 4px;
}

[hidden] {
  display: none !important;
}

.skip-link {
  position: fixed;
  z-index: 999;
  top: 12px;
  left: 12px;
  padding: 10px 16px;
  transform: translateY(-150%);
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
}

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

.site-shell {
  display: grid;
  grid-template-columns: var(--rail-width) minmax(0, 1fr);
  min-height: 100vh;
}

.site-rail {
  position: sticky;
  z-index: 20;
  top: 0;
  display: flex;
  height: 100vh;
  flex-direction: column;
  padding: 28px 24px 22px;
  border-right: 1px solid rgba(22, 34, 58, 0.12);
  background: rgba(244, 246, 243, 0.88);
  backdrop-filter: blur(18px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  display: flex;
  width: 38px;
  height: 38px;
  align-items: center;
  justify-content: center;
  gap: 3px;
  border-radius: 50%;
  background: var(--ink);
}

.brand-mark i {
  width: 2px;
  height: var(--bar-h, 14px);
  border-radius: 2px;
  background: var(--mint);
}

.brand-mark i:nth-child(1),
.brand-mark i:nth-child(5) { --bar-h: 8px; }
.brand-mark i:nth-child(2),
.brand-mark i:nth-child(4) { --bar-h: 15px; }
.brand-mark i:nth-child(3) { --bar-h: 22px; background: var(--amber); }

.brand-copy {
  display: grid;
  line-height: 1.2;
}

.brand-copy strong {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.13em;
}

.brand-copy small {
  margin-top: 5px;
  color: var(--ink-soft);
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.08em;
}

.case-nav {
  display: grid;
  gap: 4px;
  margin-top: 104px;
}

.case-nav a {
  position: relative;
  display: grid;
  grid-template-columns: 1fr auto;
  padding: 16px 10px 16px 14px;
  border-left: 2px solid transparent;
  color: var(--ink-soft);
  font-size: 13px;
  transition: 180ms ease;
}

.case-nav a:hover,
.case-nav a[aria-current="page"] {
  border-left-color: var(--route-accent, var(--voice));
  background: rgba(255, 255, 255, 0.54);
  color: var(--ink);
}

.case-nav a:nth-child(2) {
  --route-accent: var(--director);
}

.case-nav .nav-index {
  grid-column: 1 / -1;
  margin-bottom: 4px;
  color: var(--route-accent, var(--voice));
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.12em;
}

.case-nav a i {
  font-style: normal;
}

.rail-footer {
  margin-top: auto;
}

.reading-progress {
  height: 2px;
  overflow: hidden;
  background: var(--line);
}

.reading-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--ink);
  transition: width 120ms linear;
}

.rail-footer > p {
  display: flex;
  justify-content: space-between;
  margin: 8px 0 18px;
  color: var(--ink-soft);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.08em;
}

.rail-footer > p b {
  color: var(--ink);
  font-weight: 500;
}

.rail-controls {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border: 1px solid var(--line);
}

.rail-controls a {
  display: grid;
  height: 42px;
  place-items: center;
  font-size: 18px;
  transition: 180ms ease;
}

.rail-controls a + a {
  border-left: 1px solid var(--line);
}

.rail-controls a:hover {
  background: var(--ink);
  color: #fff;
}

main {
  min-width: 0;
}

.page-view {
  animation: page-in 480ms cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

@keyframes page-in {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: none; }
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 24px;
  color: var(--ink-soft);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.18em;
}

.eyebrow > span {
  width: 28px;
  height: 2px;
  background: currentColor;
}

/* Cover */

.cover-view {
  max-width: 1360px;
  min-height: 100vh;
  margin: 0 auto;
  padding: clamp(56px, 8vw, 116px) clamp(30px, 6vw, 96px) 56px;
}

.cover-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(330px, 0.88fr);
  align-items: center;
  gap: 56px;
}

.cover-copy h1,
.case-hero h1,
.section-heading h2,
.takeaway-section > h2 {
  margin: 0;
  font-family: var(--display);
  font-weight: 760;
  letter-spacing: -0.055em;
  line-height: 1.04;
}

.cover-copy h1 {
  max-width: 820px;
  font-size: clamp(36px, 4.6vw, 66px);
  letter-spacing: -0.045em;
  line-height: 1.08;
}

.cover-copy h1 span {
  position: relative;
  display: inline-block;
  color: var(--voice);
}

.cover-copy h1 span::after {
  position: absolute;
  right: 0;
  bottom: -6px;
  left: 0;
  height: 5px;
  background: repeating-linear-gradient(90deg, var(--voice) 0 12px, transparent 12px 18px);
  content: "";
}

.cover-lead {
  max-width: 670px;
  margin: 34px 0 26px;
  color: var(--ink-soft);
  font-size: clamp(16px, 1.4vw, 20px);
  line-height: 1.9;
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--ink);
  font-size: 13px;
  font-weight: 700;
}

.text-link span {
  font-size: 18px;
  transition: transform 180ms ease;
}

.text-link:hover span {
  transform: translateX(5px);
}

.signal-sculpture {
  position: relative;
  display: grid;
  aspect-ratio: 1;
  place-items: center;
}

.signal-sculpture::before {
  position: absolute;
  width: 64%;
  aspect-ratio: 1;
  border: 1px solid rgba(22, 34, 58, 0.16);
  border-radius: 50%;
  content: "";
}

.signal-orbit {
  position: absolute;
  aspect-ratio: 1;
  border: 1px dashed rgba(22, 34, 58, 0.22);
  border-radius: 50%;
  animation: orbit-spin 22s linear infinite;
}

.signal-orbit::after {
  position: absolute;
  top: 50%;
  left: -5px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--voice);
  box-shadow: 0 0 0 7px var(--voice-soft);
  content: "";
}

.orbit-a { width: 82%; }
.orbit-b { width: 48%; animation-direction: reverse; animation-duration: 14s; }
.orbit-b::after { background: var(--director); box-shadow: 0 0 0 7px var(--director-soft); }

@keyframes orbit-spin { to { transform: rotate(360deg); } }

.signal-core {
  display: flex;
  z-index: 2;
  width: 48%;
  height: 32%;
  align-items: center;
  justify-content: center;
  gap: 5px;
  border-radius: 50%;
  background: var(--console);
  box-shadow: var(--shadow);
}

.signal-core span {
  width: 3px;
  height: var(--h);
  border-radius: 3px;
  background: var(--mint);
  transform-origin: center;
  animation: level 1.6s ease-in-out infinite alternate;
}

.signal-core span:nth-child(3n) { background: var(--amber); animation-delay: -0.5s; }
.signal-core span:nth-child(2n) { animation-delay: -0.9s; }

@keyframes level { to { transform: scaleY(0.56); opacity: 0.62; } }

.signal-sculpture > p {
  position: absolute;
  bottom: 7%;
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.12em;
}

.signal-sculpture > p i {
  width: 24px;
  height: 1px;
  background: var(--line);
}

.case-portals {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: clamp(60px, 8vw, 110px);
}

.case-portal {
  position: relative;
  min-height: 330px;
  overflow: hidden;
  padding: 30px 32px;
  border: 1px solid rgba(22, 34, 58, 0.14);
  background: rgba(252, 253, 251, 0.72);
  transition: transform 240ms ease, box-shadow 240ms ease, border-color 240ms ease;
}

.case-portal:hover {
  z-index: 2;
  transform: translateY(-8px);
  border-color: var(--portal-accent);
  box-shadow: var(--shadow);
}

.portal-voice { --portal-accent: var(--voice); }
.portal-director { --portal-accent: var(--director); }

.portal-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--portal-accent);
  font-family: var(--mono);
}

.portal-top b { font-size: 26px; }
.portal-top i { font-size: 8px; font-style: normal; letter-spacing: 0.1em; }

.case-portal h2 {
  position: relative;
  z-index: 2;
  margin: 44px 0 10px;
  font-family: var(--display);
  font-size: clamp(28px, 3vw, 42px);
  letter-spacing: -0.04em;
}

.case-portal > p {
  position: relative;
  z-index: 2;
  max-width: 480px;
  margin: 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.portal-action {
  position: absolute;
  bottom: 28px;
  left: 32px;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  font-weight: 700;
}

.portal-action b {
  display: grid;
  width: 24px;
  height: 24px;
  place-items: center;
  border-radius: 50%;
  background: var(--portal-accent);
  color: #fff;
}

.portal-wave {
  position: absolute;
  right: -30px;
  bottom: 8px;
  width: 46%;
  height: 92px;
  opacity: 0.12;
  background: repeating-linear-gradient(90deg, var(--voice) 0 3px, transparent 3px 9px);
  clip-path: polygon(0 48%, 8% 15%, 16% 76%, 24% 32%, 32% 90%, 40% 8%, 48% 62%, 56% 28%, 64% 80%, 72% 42%, 80% 68%, 88% 20%, 96% 54%, 100% 48%, 100% 52%, 96% 58%, 88% 24%, 80% 72%, 72% 46%, 64% 84%, 56% 32%, 48% 66%, 40% 12%, 32% 94%, 24% 36%, 16% 80%, 8% 19%, 0 52%);
}

.portal-track {
  position: absolute;
  right: 20px;
  bottom: 22px;
  display: grid;
  width: 40%;
  gap: 7px;
  opacity: 0.2;
}

.portal-track i {
  display: block;
  height: 8px;
  background: linear-gradient(90deg, transparent 0 8%, var(--director) 8% 36%, transparent 36% 44%, var(--director) 44% 72%, transparent 72%);
}

.portal-track i:nth-child(2) { transform: translateX(18px); }
.portal-track i:nth-child(3) { transform: translateX(-8px); }

.cover-note {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr) auto;
  align-items: center;
  gap: 28px;
  margin-top: 28px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.cover-note > span,
.cover-note > i {
  color: var(--ink-soft);
  font-family: var(--mono);
  font-size: 9px;
  font-style: normal;
  letter-spacing: 0.12em;
}

.cover-note p { margin: 0; font-size: 14px; }

/* Case shell */

.case-page {
  --accent: var(--voice);
  --accent-soft: var(--voice-soft);
}

.case-director {
  --accent: var(--director);
  --accent-soft: var(--director-soft);
}

.case-hero,
.case-section {
  width: min(100% - clamp(36px, 8vw, 120px), 1180px);
  margin-inline: auto;
}

.case-hero {
  min-height: 88vh;
  padding: 36px 0 64px;
}

.case-kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: clamp(70px, 10vw, 130px);
  color: var(--ink-soft);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.12em;
}

.case-kicker a { border-bottom: 1px solid var(--line); }
.case-kicker b { color: var(--accent); font-weight: 600; }

.case-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  align-items: center;
  gap: clamp(48px, 7vw, 96px);
}

.case-hero h1 {
  max-width: 780px;
  font-size: clamp(38px, 4.8vw, 68px);
  letter-spacing: -0.045em;
  line-height: 1.08;
}

.case-hero h1 span { color: var(--accent); }

.hero-lead {
  max-width: 720px;
  margin: 32px 0 0;
  color: var(--ink-soft);
  font-size: clamp(16px, 1.45vw, 20px);
  line-height: 1.95;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(54px, 8vw, 90px) 0 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.hero-tags li {
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--ink-soft);
  font-size: 11px;
}

.hero-console {
  transform: rotate(2.5deg);
  padding: 28px;
  border: 8px solid #e0e4df;
  border-radius: 28px;
  background: #c7cec9;
  box-shadow: var(--shadow);
}

.console-screen {
  position: relative;
  display: flex;
  min-height: 310px;
  flex-direction: column;
  justify-content: flex-end;
  overflow: hidden;
  padding: 24px;
  border: 2px solid #0a1020;
  border-radius: 12px;
  background:
    linear-gradient(rgba(72, 198, 165, 0.04) 1px, transparent 1px) 0 0 / 100% 24px,
    linear-gradient(90deg, rgba(72, 198, 165, 0.04) 1px, transparent 1px) 0 0 / 24px 100%,
    #11192b;
  color: var(--mint);
}

.console-screen > span {
  position: absolute;
  top: 22px;
  left: 24px;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.1em;
}

.console-screen b {
  color: #fff;
  font-family: var(--display);
  font-size: 32px;
  letter-spacing: -0.04em;
}

.console-screen small {
  color: var(--mint);
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.14em;
}

.mini-wave {
  display: flex;
  height: 84px;
  align-items: center;
  gap: 7px;
  margin-bottom: 28px;
}

.mini-wave i {
  width: 4px;
  height: 40%;
  border-radius: 4px;
  background: var(--voice);
  box-shadow: 0 0 12px rgba(77, 107, 254, 0.7);
  animation: level 1.2s ease-in-out infinite alternate;
}

.mini-wave i:nth-child(2n) { height: 75%; animation-delay: -0.5s; }
.mini-wave i:nth-child(3n) { height: 100%; background: var(--mint); animation-delay: -0.8s; }

.console-dials {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  padding-top: 22px;
}

.console-dials i {
  width: 26px;
  height: 26px;
  border: 6px solid #adb6b0;
  border-radius: 50%;
  background: var(--ink);
}

.score-card {
  position: relative;
  min-height: 390px;
  overflow: hidden;
  padding: 26px 20px;
  transform: rotate(-2deg);
  border: 1px solid rgba(22, 34, 58, 0.12);
  background: var(--white);
  box-shadow: var(--shadow);
}

.score-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 34px;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.12em;
}

.score-head i { width: 8px; height: 8px; border-radius: 50%; background: var(--mint); }

.score-track {
  position: relative;
  display: flex;
  height: 54px;
  align-items: center;
  gap: 8px;
  margin-top: 10px;
  padding-left: 56px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.score-track b {
  position: absolute;
  left: 8px;
  color: var(--ink-soft);
  font-family: var(--mono);
  font-size: 8px;
}

.score-track i {
  display: block;
  width: 42%;
  height: 24px;
  border-radius: 4px;
  background: var(--director);
}

.score-track i:nth-of-type(2) { width: 24%; opacity: 0.7; }
.score-track i:nth-of-type(3) { width: 12%; opacity: 0.5; }
.score-track.cohost i { background: var(--amber); }
.score-track.bgm i { width: 92%; height: 12px; background: var(--voice); opacity: 0.5; }
.score-track.sfx i { width: 8%; height: 22px; background: var(--mint); }
.score-track.sfx i + i { margin-left: 42%; }

.score-playhead {
  position: absolute;
  top: 55px;
  bottom: 22px;
  left: 60%;
  width: 2px;
  background: var(--director);
  box-shadow: 0 0 0 3px rgba(240, 107, 94, 0.12);
  animation: playhead 5s ease-in-out infinite alternate;
}

@keyframes playhead { to { transform: translateX(66px); } }

.case-section {
  padding: clamp(88px, 11vw, 150px) 0;
  border-top: 1px solid var(--line);
}

.section-heading > p,
.split-heading > div > p {
  margin: 0 0 26px;
  color: var(--accent);
  font-family: var(--mono);
  font-size: 9px;
  font-weight: 600;
  letter-spacing: 0.16em;
}

.section-heading h2 {
  font-size: clamp(36px, 4.8vw, 66px);
}

.split-heading {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(280px, 0.75fr);
  align-items: end;
  gap: 60px;
}

.split-heading > p {
  margin: 0 0 4px;
  color: var(--ink-soft);
  font-size: 15px;
  line-height: 1.85;
}

.problem-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(360px, 1.08fr);
  gap: clamp(50px, 9vw, 120px);
  margin-top: 72px;
}

.section-intro {
  margin: 0;
  color: var(--ink-soft);
  font-size: 18px;
  line-height: 2;
}

.friction-list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: friction;
}

.friction-list li {
  display: grid;
  grid-template-columns: 78px 1fr;
  align-items: baseline;
  padding: 16px 0;
  border-top: 1px solid var(--line);
  counter-increment: friction;
}

.friction-list li:last-child { border-bottom: 1px solid var(--line); }
.friction-list b { color: var(--accent); font-size: 17px; }
.friction-list span { color: var(--ink-soft); font-size: 14px; }

.thesis-quote {
  position: relative;
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr);
  gap: 36px;
  margin: 92px 0 0;
  padding: 36px 42px;
  border: 0;
  background: var(--accent-soft);
}

.thesis-quote::before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 4px;
  background: var(--accent);
  content: "";
}

.thesis-quote span {
  color: var(--accent);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.12em;
}

.thesis-quote p {
  max-width: 820px;
  margin: 0;
  font-family: var(--display);
  font-size: clamp(20px, 2.2vw, 30px);
  font-weight: 650;
  letter-spacing: -0.025em;
  line-height: 1.5;
}

.closure-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-top: 72px;
  border: 1px solid var(--line);
  background: rgba(252, 253, 251, 0.56);
}

.closure-strip article {
  position: relative;
  min-height: 210px;
  padding: 26px 24px;
}

.closure-strip article + article { border-left: 1px solid var(--line); }
.closure-strip article::after { position: absolute; right: -9px; top: 46%; z-index: 2; color: var(--accent); content: "→"; }
.closure-strip article:last-child::after { display: none; }

.closure-strip span {
  color: var(--accent);
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.14em;
}

.closure-strip b {
  display: block;
  margin-top: 40px;
  font-family: var(--display);
  font-size: 23px;
}

.closure-strip p { margin: 8px 0 0; color: var(--ink-soft); font-size: 12px; }

.decision-notes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  margin-top: 20px;
  background: var(--line);
}

.decision-notes article {
  min-height: 250px;
  padding: 28px;
  background: var(--paper);
}

.decision-notes i {
  color: var(--accent);
  font-family: var(--mono);
  font-size: 9px;
  font-style: normal;
}

.decision-notes h3 { margin: 58px 0 12px; font-size: 18px; line-height: 1.5; }
.decision-notes p { margin: 0; color: var(--ink-soft); font-size: 13px; }

/* Framework diagrams */

.framework-section {
  width: 100%;
  max-width: none;
  padding-inline: clamp(24px, 5vw, 76px);
  background: var(--console);
  color: #f5f8ff;
}

.framework-section > .section-heading,
.framework-stage {
  width: min(100%, 1320px);
  margin-inline: auto;
}

.inverse-heading > div > p { color: var(--mint); }
.inverse-heading > p { color: #a9b4c8; }

.framework-stage {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 18px;
  margin-top: 64px;
}

.diagram-scroll {
  min-width: 0;
  overflow-x: auto;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background:
    linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px) 0 0 / 40px 40px,
    linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px) 0 0 / 40px 40px,
    #0d1526;
  scrollbar-color: var(--mint) var(--console-soft);
}

.diagram-canvas {
  position: relative;
  width: 960px;
  height: 650px;
  margin: 0 auto;
}

.director-diagram { width: 1020px; height: 640px; }

.diagram-lines {
  position: absolute;
  z-index: 0;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
}

.diagram-lines path {
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.line-muted path {
  stroke: rgba(132, 153, 191, 0.36);
  stroke-width: 1.5;
}

.line-signal path {
  stroke: var(--mint);
  stroke-width: 2;
  stroke-dasharray: 9 8;
  animation: signal-flow 1.3s linear infinite;
}

@keyframes signal-flow { to { stroke-dashoffset: -34; } }

.diagram-lines marker path { fill: var(--mint); stroke: none; }

.signal-pulse {
  fill: var(--amber);
  filter: drop-shadow(0 0 7px rgba(243, 180, 78, 0.95));
  animation: pulse-dot 1.6s ease-in-out infinite;
}

.pulse-two { animation-delay: -0.8s; }

@keyframes pulse-dot { 50% { opacity: 0.3; r: 8; } }

.diagram-lane {
  position: absolute;
  top: 88px;
  color: #7989a6;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.12em;
}

.lane-left { left: 148px; }
.lane-right { right: 148px; }

.flow-node {
  position: absolute;
  z-index: 2;
  top: calc(var(--y) * 1%);
  left: calc(var(--x) * 1%);
  display: flex;
  width: 168px;
  min-height: 54px;
  align-items: flex-start;
  justify-content: center;
  flex-direction: column;
  padding: 10px 13px;
  transform: translate(-50%, -50%);
  border: 1px solid rgba(170, 188, 220, 0.32);
  border-radius: 7px;
  background: rgba(22, 34, 58, 0.92);
  color: #edf3ff;
  text-align: left;
  cursor: pointer;
  transition: 180ms ease;
}

.flow-node:hover,
.flow-node.is-active {
  z-index: 4;
  transform: translate(-50%, -50%) translateY(-3px);
  border-color: var(--mint);
  background: #1c2a47;
  box-shadow: 0 0 0 3px rgba(72, 198, 165, 0.12), 0 14px 30px rgba(0, 0, 0, 0.28);
}

.framework-stage.has-selection .flow-node:not(.is-active),
.framework-stage.has-selection .delivery-rail button:not(.is-active) {
  opacity: 0.6;
}

.flow-node small,
.material-pool small {
  margin-bottom: 3px;
  color: var(--mint);
  font-family: var(--mono);
  font-size: 7px;
  letter-spacing: 0.1em;
}

.flow-node b { font-size: 11px; font-weight: 650; line-height: 1.35; }
.flow-node span { margin-top: 3px; color: #93a1ba; font-size: 8px; }

.branch-node { min-height: 56px; border-color: rgba(77, 107, 254, 0.55); }
.input-node { min-height: 52px; background: rgba(27, 39, 65, 0.78); }
.wide-node { width: 290px; }
.system-node { width: 260px; border-color: rgba(72, 198, 165, 0.58); }
.model-bank { width: 520px; min-height: 54px; border-color: rgba(243, 180, 78, 0.48); }
.model-bank small { color: var(--amber); }
.validate-node { width: 190px; }
.output-node { width: 180px; border-color: rgba(77, 107, 254, 0.62); }

.diagram-inspector {
  display: flex;
  min-height: 650px;
  flex-direction: column;
  padding: 28px 26px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: var(--console-soft);
}

.diagram-inspector > p:first-child {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin: 0;
  color: var(--mint);
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.1em;
}

.diagram-inspector > p:first-child i {
  color: #6e7d97;
  font-style: normal;
}

.diagram-inspector h3 {
  margin: 66px 0 22px;
  font-family: var(--display);
  font-size: 25px;
  letter-spacing: -0.035em;
  line-height: 1.35;
}

.diagram-inspector > p[data-node-body] {
  margin: 24px 0 0;
  color: #aeb9cc;
  font-size: 13px;
  line-height: 1.85;
}

.inspector-wave {
  display: flex;
  height: 34px;
  align-items: center;
  gap: 4px;
}

.inspector-wave i {
  width: 2px;
  height: 40%;
  background: var(--voice);
}

.inspector-wave i:nth-child(2n) { height: 88%; }
.inspector-wave i:nth-child(3n) { height: 62%; background: var(--mint); }

.delivery-rail {
  display: grid;
  gap: 8px;
  margin-top: auto;
}

.delivery-rail button {
  display: grid;
  gap: 2px;
  padding: 12px 14px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 5px;
  background: transparent;
  color: #fff;
  text-align: left;
  cursor: pointer;
}

.delivery-rail button:hover,
.delivery-rail button.is-active { border-color: var(--mint); background: rgba(72, 198, 165, 0.07); }
.delivery-rail button b { font-size: 11px; }
.delivery-rail button span { color: #8f9db5; font-size: 8px; }

.layer-rules path,
.lane-rules path {
  stroke: rgba(255, 255, 255, 0.1);
  stroke-width: 1;
  stroke-dasharray: 4 6;
}

.layer-label {
  position: absolute;
  left: 20px;
  display: flex;
  align-items: center;
  gap: 8px;
  color: #8090ac;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.1em;
  writing-mode: vertical-rl;
}

.layer-label i { color: var(--director); font-style: normal; }
.label-understand { top: 64px; }
.label-generate { top: 227px; }
.label-direct { top: 407px; }

.director-signal path { stroke: var(--director); }
.director-diagram marker path { fill: var(--director); }
.director-pulse { fill: var(--amber); }

.voice-id-node { width: 190px; }
.tts-node { width: 160px; border-color: rgba(240, 107, 94, 0.55); }
.duration-node { width: 200px; }

.material-pool {
  position: absolute;
  z-index: 2;
  top: 75%;
  left: 17%;
  display: flex;
  width: 225px;
  min-height: 68px;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 6px;
  padding: 10px;
  transform: translate(-50%, -50%);
  border: 1px dashed rgba(243, 180, 78, 0.42);
  border-radius: 8px;
}

.material-pool small { width: 100%; color: var(--amber); text-align: center; }
.material-pool b { padding: 4px 8px; border-radius: 4px; background: rgba(243, 180, 78, 0.1); color: var(--amber); font-size: 8px; }

.timeline-node { width: 190px; border-color: rgba(240, 107, 94, 0.58); }
.rules-node { width: 180px; }
.mix-node { width: 150px; border-color: rgba(72, 198, 165, 0.55); }
.feedback-node { width: 240px; border-style: dashed; }

.feedback-line {
  fill: none;
  stroke: var(--amber);
  stroke-width: 1.5;
  stroke-dasharray: 5 7;
  animation: signal-flow 1.5s linear infinite reverse;
}

.inspector-track {
  display: grid;
  gap: 5px;
  margin: 2px 0 0;
}

.inspector-track i {
  display: block;
  height: 6px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--director) 0 46%, transparent 46% 53%, var(--director) 53% 76%, transparent 76%);
}

.inspector-track i:nth-child(2) { transform: translateX(12px); background: linear-gradient(90deg, var(--amber) 0 28%, transparent 28% 40%, var(--amber) 40% 64%, transparent 64%); }
.inspector-track i:nth-child(3) { height: 3px; background: var(--voice); opacity: 0.7; }
.inspector-track i:nth-child(4) { width: 70%; background: linear-gradient(90deg, transparent 0 20%, var(--mint) 20% 26%, transparent 26% 68%, var(--mint) 68% 74%, transparent 74%); }

.layer-key {
  display: grid;
  gap: 8px;
  margin-top: auto;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.layer-key span { display: flex; align-items: center; gap: 8px; color: #9ca9be; font-size: 9px; }
.layer-key i { width: 8px; height: 8px; border-radius: 50%; background: var(--director); }
.layer-key span:nth-child(2) i { background: var(--mint); }
.layer-key span:nth-child(3) i { background: var(--amber); }

/* Supporting content */

.model-rulebook {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  margin-top: 72px;
  border: 1px solid var(--line);
  background: var(--line);
}

.model-rulebook article {
  position: relative;
  min-height: 300px;
  padding: 28px;
  background: var(--paper);
}

.model-rulebook article:hover { z-index: 2; background: var(--white); box-shadow: var(--shadow); }
.model-rulebook span { color: var(--accent); font-family: var(--mono); font-size: 10px; }
.model-rulebook h3 { margin: 60px 0 12px; font-family: var(--display); font-size: 23px; }
.model-rulebook p { margin: 0; color: var(--ink-soft); font-size: 13px; }
.model-rulebook i { position: absolute; right: 26px; bottom: 24px; color: #8a968f; font-family: var(--mono); font-size: 8px; font-style: normal; letter-spacing: 0.1em; }

.iteration-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 72px;
}

.iteration-grid article {
  min-height: 230px;
  padding: 28px 30px;
  border: 1px solid var(--line);
  background: rgba(252, 253, 251, 0.4);
}

.iteration-grid span { color: var(--accent); font-family: var(--mono); font-size: 9px; letter-spacing: 0.1em; }
.iteration-grid h3 { margin: 48px 0 12px; font-size: 20px; }
.iteration-grid p { margin: 0; color: var(--ink-soft); font-size: 13px; }

.takeaway-section {
  border-top: 0;
  background: var(--accent);
  color: #fff;
}

.takeaway-section::before {
  display: block;
  width: 100%;
  height: 1px;
  margin-bottom: clamp(88px, 11vw, 150px);
  background: rgba(255, 255, 255, 0.32);
  content: "";
}

.takeaway-section .eyebrow { color: rgba(255, 255, 255, 0.68); }

.takeaway-section > h2 {
  max-width: 1000px;
  font-size: clamp(34px, 4.4vw, 62px);
  line-height: 1.2;
}

.takeaway-section > h2 span { color: var(--console); }

.takeaway-points {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 70px;
  padding-top: 28px;
  border-top: 1px solid rgba(255, 255, 255, 0.32);
}

.takeaway-points p { margin: 0; color: rgba(255, 255, 255, 0.8); font-size: 13px; }
.takeaway-points b { display: block; margin-bottom: 12px; color: #fff; font-size: 15px; }

.next-case {
  display: grid;
  grid-template-columns: 130px 1fr auto;
  align-items: center;
  gap: 20px;
  margin-top: 100px;
  padding: 26px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.32);
  border-bottom: 1px solid rgba(255, 255, 255, 0.32);
}

.next-case span { font-family: var(--mono); font-size: 8px; letter-spacing: 0.12em; }
.next-case b { font-family: var(--display); font-size: clamp(18px, 2vw, 26px); }
.next-case i { font-size: 24px; font-style: normal; transition: transform 180ms ease; }
.next-case:hover i { transform: translateX(8px); }

.sound-layers {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  margin-top: 72px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--line);
}

.sound-layers article {
  min-height: 260px;
  padding: 28px 24px;
  background: var(--paper);
}

.sound-layers span { color: var(--accent); font-family: var(--mono); font-size: 10px; }
.sound-layers h3 { margin: 62px 0 10px; font-size: 18px; }
.sound-layers p { margin: 0; color: var(--ink-soft); font-size: 12px; }

.mvp-score {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0 60px;
  margin: 72px 0 0;
  padding: 0;
  list-style: none;
}

.mvp-score li {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 20px;
  padding: 28px 0;
  border-top: 1px solid var(--line);
}

.mvp-score li:nth-last-child(-n + 2) { border-bottom: 1px solid var(--line); }
.mvp-score > li > span { color: var(--accent); font-family: var(--mono); font-size: 12px; }
.mvp-score b { font-size: 17px; }
.mvp-score p { margin: 8px 0 0; color: var(--ink-soft); font-size: 13px; }

.responsibility-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 72px;
}

.responsibility-grid article {
  min-height: 370px;
  padding: 30px;
  border: 1px solid var(--line);
}

.responsibility-grid span { color: var(--role-color); font-family: var(--mono); font-size: 9px; letter-spacing: 0.11em; }
.responsibility-grid h3 { margin: 70px 0 24px; font-family: var(--display); font-size: 28px; }
.responsibility-grid ul { display: grid; gap: 10px; margin: 0; padding: 0; color: var(--ink-soft); list-style: none; font-size: 13px; }
.responsibility-grid li::before { margin-right: 10px; color: var(--role-color); content: "—"; }
.responsibility-ai { --role-color: var(--director); background: var(--director-soft); }
.responsibility-rule { --role-color: var(--mint); background: #e0f4ed; }
.responsibility-human { --role-color: var(--amber); background: #faedcf; }

.before-after-list {
  margin-top: 72px;
  border-top: 1px solid var(--line);
}

.before-after-list article {
  display: grid;
  grid-template-columns: 92px 1fr 46px 1fr;
  align-items: center;
  gap: 24px;
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}

.before-after-list article > span { color: var(--accent); font-family: var(--mono); font-size: 10px; letter-spacing: 0.1em; }
.before-after-list small { color: #87928b; font-family: var(--mono); font-size: 8px; letter-spacing: 0.1em; }
.before-after-list p { margin: 4px 0 0; font-size: 13px; }
.before-after-list article > i { color: var(--accent); font-size: 20px; font-style: normal; }

.director-takeaway { background: var(--director); }

.noscript-note {
  position: fixed;
  z-index: 100;
  right: 20px;
  bottom: 20px;
  margin: 0;
  padding: 10px 14px;
  border-radius: 6px;
  background: var(--ink);
  color: #fff;
  font-size: 12px;
}

/* Responsive */

@media (max-width: 1100px) {
  :root { --rail-width: 224px; }
  .site-rail { padding-inline: 18px; }
  .cover-grid,
  .case-hero-grid { grid-template-columns: 1fr; }
  .signal-sculpture { width: min(100%, 470px); margin: -20px auto 0; }
  .hero-console,
  .score-card { width: min(100%, 480px); margin: 0 auto; }
  .case-hero { min-height: auto; }
  .framework-stage { grid-template-columns: 1fr; }
  .diagram-inspector { min-height: 300px; }
  .delivery-rail { grid-template-columns: repeat(2, 1fr); margin-top: 36px; }
}

@media (max-width: 820px) {
  :root { --rail-width: 0px; }
  .site-shell { display: block; }
  .site-rail {
    position: sticky;
    display: grid;
    height: auto;
    grid-template-columns: auto 1fr;
    align-items: center;
    padding: 12px 16px;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .brand-copy { display: none; }
  .brand-mark { width: 34px; height: 34px; }
  .case-nav { display: flex; justify-content: flex-end; gap: 0; margin: 0; }
  .case-nav a { display: block; padding: 9px 10px; border: 0; border-radius: 5px; font-size: 11px; }
  .case-nav a:hover,
  .case-nav a[aria-current="page"] { border: 0; }
  .case-nav .nav-index,
  .case-nav a i { display: none; }
  .rail-footer { display: none; }
  .cover-view { padding-top: 62px; }
  .case-portals { grid-template-columns: 1fr; }
  .case-portal { min-height: 300px; }
  .cover-note { grid-template-columns: 90px 1fr; }
  .cover-note > i { display: none; }
  .case-kicker { margin-bottom: 74px; }
  .split-heading,
  .problem-layout { grid-template-columns: 1fr; gap: 32px; }
  .closure-strip { grid-template-columns: repeat(2, 1fr); }
  .closure-strip article:nth-child(3) { border-left: 0; border-top: 1px solid var(--line); }
  .closure-strip article:nth-child(4) { border-top: 1px solid var(--line); }
  .closure-strip article:nth-child(2)::after { display: none; }
  .decision-notes,
  .model-rulebook,
  .responsibility-grid { grid-template-columns: 1fr; }
  .decision-notes article,
  .model-rulebook article { min-height: 230px; }
  .sound-layers { grid-template-columns: repeat(2, 1fr); }
  .mvp-score { grid-template-columns: 1fr; gap: 0; }
  .mvp-score li:nth-last-child(2) { border-bottom: 0; }
  .takeaway-points { grid-template-columns: 1fr; }
  .next-case { grid-template-columns: 1fr auto; }
  .next-case span { grid-column: 1 / -1; }
}

@media (max-width: 600px) {
  body { background-size: 54px 54px; }
  .site-rail { grid-template-columns: auto minmax(0, 1fr); }
  .case-nav a { padding-inline: 8px; font-size: 10px; }
  .case-nav a:first-child { max-width: 94px; }
  .case-nav a:last-child { max-width: 116px; }
  .cover-view { padding-inline: 22px; }
  .cover-copy h1 { font-size: 36px; }
  .cover-lead { font-size: 15px; }
  .signal-sculpture { width: 100%; }
  .case-portal { padding: 24px; }
  .portal-action { left: 24px; }
  .cover-note { display: block; }
  .cover-note p { margin-top: 8px; }
  .case-hero,
  .case-section { width: calc(100% - 36px); }
  .case-hero { padding-top: 26px; }
  .case-hero h1 { font-size: 38px; }
  .hero-lead { font-size: 15px; }
  .hero-console { padding: 18px; border-width: 6px; border-radius: 20px; }
  .console-screen { min-height: 260px; }
  .score-card { min-height: 350px; }
  .section-heading h2 { font-size: 38px; }
  .section-intro { font-size: 16px; }
  .thesis-quote { grid-template-columns: 1fr; gap: 16px; padding: 28px; }
  .closure-strip { grid-template-columns: 1fr; }
  .closure-strip article { min-height: 170px; }
  .closure-strip article + article { border-top: 1px solid var(--line); border-left: 0; }
  .closure-strip article::after { display: none; }
  .iteration-grid,
  .sound-layers { grid-template-columns: 1fr; }
  .sound-layers article { min-height: 220px; }
  .framework-section { width: 100%; padding-inline: 18px; }
  .framework-section > .section-heading,
  .framework-stage { width: 100%; }
  .diagram-inspector { padding: 24px 20px; }
  .diagram-inspector h3 { margin-top: 46px; }
  .delivery-rail { grid-template-columns: 1fr; }
  .before-after-list article { grid-template-columns: 70px 1fr; gap: 14px; }
  .before-after-list article > i { display: none; }
  .before-after-list article > div:last-child { grid-column: 2; }
  .next-case { margin-top: 70px; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

@media print {
  @page { margin: 16mm; }
  body { background: #fff; color: #000; }
  .site-shell { display: block; }
  .site-rail,
  .skip-link,
  .next-case,
  .diagram-inspector { display: none !important; }
  .page-view[hidden] { display: none !important; }
  .case-hero,
  .case-section { width: 100%; padding-block: 28px; break-inside: avoid; }
  .framework-section { padding-inline: 0; background: #fff; color: #000; }
  .framework-stage { display: block; }
  .diagram-scroll { overflow: visible; border: 1px solid #999; background: #fff; zoom: 0.72; }
  .flow-node { border-color: #777; background: #fff; color: #000; box-shadow: none; }
  .flow-node small,
  .flow-node span { color: #555; }
  .takeaway-section { background: #fff; color: #000; }
  .takeaway-section > h2 span { color: #000; }
}