:root {
  color-scheme: light;
  --color-ink: #13231f;
  --color-ink-soft: #42554f;
  --color-paper: #eaf0ec;
  --color-surface: #f8faf7;
  --color-surface-deep: #dde7e1;
  --color-blueprint: #214f70;
  --color-jade: #2f756a;
  --color-signal: #e26435;
  --color-amber: #f0b64b;
  --color-line: #b7c6be;
  --color-danger: #b33d3d;
  --color-focus: #6d55c5;
  --font-display: "Songti SC", "STSong", "Noto Serif CJK SC", serif;
  --font-body: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-utility: "SFMono-Regular", "Cascadia Code", "Liberation Mono", monospace;
  --radius-sm: 0.5rem;
  --radius-md: 0.9rem;
  --radius-lg: 1.5rem;
  --radius-full: 999px;
  --space-rhythm: 0.75rem;
  --space-section: 6rem;
  --page-gutter: clamp(1rem, 4vw, 3rem);
  --page-max: 78rem;
  --header-height: 4.5rem;
  --shadow-float: 0 1.25rem 3.75rem rgb(19 35 31 / 0.13);
  --shadow-control: 0 0.55rem 1.5rem rgb(19 35 31 / 0.1);
  --ease-field: cubic-bezier(0.22, 0.78, 0.28, 1);
  --duration-fast: 180ms;
  --duration-medium: 360ms;
  --duration-slow: 560ms;
  scrollbar-color: var(--color-jade) var(--color-surface-deep);
  scrollbar-width: thin;
}

* {
  box-sizing: border-box;
}

*::selection {
  color: var(--color-surface);
  background: var(--color-blueprint);
}

*::-webkit-scrollbar {
  width: 0.72rem;
  height: 0.72rem;
}

*::-webkit-scrollbar-track {
  background: var(--color-surface-deep);
}

*::-webkit-scrollbar-thumb {
  border: 0.17rem solid var(--color-surface-deep);
  border-radius: var(--radius-full);
  background: var(--color-jade);
}

*::-webkit-scrollbar-thumb:hover {
  background: var(--color-blueprint);
}

*::-webkit-scrollbar-thumb:active {
  background: var(--color-ink);
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 1.5rem);
}

body {
  min-width: 20rem;
  margin: 0;
  color: var(--color-ink);
  background:
    linear-gradient(90deg, rgb(33 79 112 / 0.035) 1px, transparent 1px) 0 0 / 4.5rem 4.5rem,
    linear-gradient(rgb(33 79 112 / 0.035) 1px, transparent 1px) 0 0 / 4.5rem 4.5rem,
    var(--color-paper);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-blueprint);
  text-underline-offset: 0.24em;
  text-decoration-thickness: 0.08em;
}

a:hover {
  color: var(--color-signal);
}

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

button {
  font: inherit;
}

button:not(:disabled),
a[href],
summary {
  cursor: pointer;
}

button:focus-visible,
a:focus-visible,
summary:focus-visible {
  outline: 0.2rem solid var(--color-focus);
  outline-offset: 0.22rem;
  box-shadow: 0 0 0 0.18rem var(--color-surface);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.48;
}

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

h1,
h2,
h3,
h4,
p,
dl,
dd,
blockquote {
  margin-top: 0;
}

h1,
h2,
h3,
h4 {
  line-height: 1.14;
  text-wrap: balance;
}

p {
  text-wrap: pretty;
}

code {
  font-family: var(--font-utility);
  font-size: 0.83em;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: clip;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.7rem 1rem;
  color: var(--color-surface);
  background: var(--color-ink);
  border-radius: var(--radius-sm);
  transform: translateY(-180%);
  transition: transform var(--duration-fast) ease;
}

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

.reading-progress {
  position: fixed;
  z-index: 800;
  inset: 0 0 auto;
  height: 0.2rem;
  background: transparent;
}

.reading-progress span {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--color-blueprint), var(--color-jade), var(--color-signal));
  transform: scaleX(0);
  transform-origin: left;
}

.site-header {
  position: sticky;
  z-index: 700;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height);
  padding: 0.7rem var(--page-gutter);
  border-bottom: 1px solid color-mix(in srgb, var(--color-line) 72%, transparent);
  background: color-mix(in srgb, var(--color-paper) 87%, transparent);
  backdrop-filter: blur(1rem) saturate(120%);
}

.brand {
  display: inline-grid;
  grid-template-columns: auto auto;
  column-gap: 0.65rem;
  align-items: center;
  color: var(--color-ink);
  font-weight: 760;
  line-height: 1;
  text-decoration: none;
}

.brand:hover {
  color: var(--color-blueprint);
}

.brand small {
  grid-column: 2;
  margin-top: 0.25rem;
  color: var(--color-ink-soft);
  font-family: var(--font-utility);
  font-size: 0.59rem;
  font-weight: 500;
  letter-spacing: 0.13em;
}

.brand-mark {
  position: relative;
  grid-row: 1 / span 2;
  width: 2rem;
  height: 2rem;
  border: 1px solid var(--color-blueprint);
  border-radius: 50%;
}

.brand-mark::before,
.brand-mark::after {
  position: absolute;
  content: "";
  background: var(--color-line);
  transform-origin: left center;
}

.brand-mark::before {
  width: 1.15rem;
  height: 1px;
  top: 0.86rem;
  left: 0.44rem;
  transform: rotate(28deg);
}

.brand-mark::after {
  width: 0.95rem;
  height: 1px;
  top: 1.18rem;
  left: 0.55rem;
  transform: rotate(-45deg);
}

.brand-mark i {
  position: absolute;
  z-index: 1;
  width: 0.38rem;
  height: 0.38rem;
  border: 2px solid var(--color-paper);
  border-radius: 50%;
  background: var(--color-signal);
}

.brand-mark i:nth-child(1) {
  top: 0.27rem;
  left: 0.3rem;
}

.brand-mark i:nth-child(2) {
  top: 0.52rem;
  right: 0.22rem;
  background: var(--color-jade);
}

.brand-mark i:nth-child(3) {
  bottom: 0.16rem;
  left: 0.8rem;
  background: var(--color-amber);
}

.chapter-nav {
  display: flex;
  align-items: center;
  gap: 0.15rem;
}

.chapter-nav a {
  position: relative;
  padding: 0.5rem 0.66rem;
  color: var(--color-ink-soft);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 650;
  text-decoration: none;
  transition: color var(--duration-fast) ease, background var(--duration-fast) ease;
}

.chapter-nav a:hover,
.chapter-nav a[aria-current="location"] {
  color: var(--color-ink);
  background: var(--color-surface-deep);
}

.section-shell {
  width: min(100% - (var(--page-gutter) * 2), var(--page-max));
  margin-inline: auto;
  padding-block: var(--space-section);
  scroll-margin-top: calc(var(--header-height) + 1.5rem);
}

.eyebrow,
.utility-label {
  color: var(--color-blueprint);
  font-family: var(--font-utility);
  font-size: 0.7rem;
  font-weight: 680;
  letter-spacing: 0.13em;
  line-height: 1.45;
  text-transform: uppercase;
}

.eyebrow {
  margin-bottom: 1.25rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.8rem;
  padding: 0.7rem 1.15rem;
  border: 1px solid transparent;
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  font-weight: 720;
  line-height: 1;
  text-decoration: none;
  transition:
    transform var(--duration-fast) var(--ease-field),
    color var(--duration-fast) ease,
    background var(--duration-fast) ease,
    border-color var(--duration-fast) ease,
    box-shadow var(--duration-fast) ease;
}

.button:not(:disabled):hover {
  transform: translateY(-0.12rem);
}

.button:not(:disabled):active {
  transform: translateY(0.05rem);
}

.button-primary {
  color: var(--color-surface);
  background: var(--color-ink);
  box-shadow: var(--shadow-control);
}

.button-primary:hover {
  color: var(--color-surface);
  background: var(--color-blueprint);
}

.button-quiet {
  color: var(--color-ink);
  border-color: var(--color-line);
  background: color-mix(in srgb, var(--color-surface) 58%, transparent);
}

.button-quiet:hover {
  color: var(--color-ink);
  border-color: var(--color-ink-soft);
  background: var(--color-surface);
}

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

.button-danger:hover {
  color: var(--color-surface);
  background: color-mix(in srgb, var(--color-danger) 82%, var(--color-ink));
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.78fr) minmax(33rem, 1.22fr);
  gap: clamp(2.5rem, 6vw, 6.5rem);
  align-items: center;
  min-height: 47rem;
  padding-top: clamp(4rem, 9vw, 8rem);
}

.hero-copy {
  position: relative;
}

.hero-copy::before {
  position: absolute;
  z-index: -1;
  top: -2rem;
  left: -4rem;
  width: 10rem;
  height: 10rem;
  border: 1px dashed color-mix(in srgb, var(--color-blueprint) 26%, transparent);
  border-radius: 50%;
  content: "";
}

.hero h1 {
  max-width: 8.5em;
  margin-bottom: 1.6rem;
  font-family: var(--font-display);
  font-size: clamp(3.1rem, 7.3vw, 6.8rem);
  font-weight: 700;
  letter-spacing: -0.055em;
  line-height: 0.98;
}

.hero h1 em {
  color: var(--color-blueprint);
  font-style: normal;
}

.hero-lede {
  max-width: 36rem;
  margin-bottom: 1.8rem;
  color: var(--color-ink-soft);
  font-size: clamp(1rem, 1.35vw, 1.16rem);
}

.hero-lede strong {
  color: var(--color-ink);
  font-weight: 750;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.hero-legend {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.7rem;
  margin: 3.4rem 0 0;
  padding-top: 1.1rem;
  border-top: 1px solid var(--color-line);
}

.hero-legend div {
  min-width: 0;
}

.hero-legend dt {
  margin-bottom: 0.25rem;
  color: var(--color-signal);
  font-family: var(--font-utility);
  font-size: 0.66rem;
}

.hero-legend dd {
  margin: 0;
  color: var(--color-ink-soft);
  font-size: 0.74rem;
  line-height: 1.45;
}

.hero-graph-wrap {
  min-width: 0;
}

.graph-card {
  position: relative;
  min-height: 41rem;
  border: 1px solid color-mix(in srgb, var(--color-blueprint) 35%, var(--color-line));
  border-radius: var(--radius-lg);
  background:
    linear-gradient(90deg, rgb(33 79 112 / 0.04) 1px, transparent 1px) 0 0 / 2rem 2rem,
    linear-gradient(rgb(33 79 112 / 0.04) 1px, transparent 1px) 0 0 / 2rem 2rem,
    color-mix(in srgb, var(--color-surface) 91%, transparent);
  box-shadow: var(--shadow-float);
  overflow: clip;
}

.graph-card::before {
  position: absolute;
  inset: 0;
  pointer-events: none;
  content: "";
  background: radial-gradient(circle at 48% 42%, transparent 30%, rgb(19 35 31 / 0.035) 100%);
}

.graph-toolbar {
  position: relative;
  z-index: 3;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 3.25rem;
  padding: 0.78rem 1rem;
  border-bottom: 1px solid var(--color-line);
  font-family: var(--font-utility);
  font-size: 0.66rem;
  letter-spacing: 0.04em;
}

.graph-toolbar > div {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.status-dot {
  width: 0.52rem;
  height: 0.52rem;
  border: 2px solid var(--color-surface);
  border-radius: 50%;
  background: var(--color-jade);
  box-shadow: 0 0 0 1px var(--color-jade);
}

.graph-toolbar .utility-label {
  margin: 0;
  color: var(--color-ink-soft);
  font-size: 0.58rem;
  text-align: right;
}

.lens-switcher {
  position: absolute;
  z-index: 5;
  top: 4.1rem;
  left: 50%;
  display: flex;
  gap: 0.25rem;
  padding: 0.28rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-full);
  background: color-mix(in srgb, var(--color-surface) 88%, transparent);
  box-shadow: var(--shadow-control);
  transform: translateX(-50%);
}

.lens-switcher button {
  min-width: 4.6rem;
  min-height: 2rem;
  padding: 0.38rem 0.7rem;
  color: var(--color-ink-soft);
  border: 0;
  border-radius: var(--radius-full);
  background: transparent;
  font-size: 0.73rem;
  font-weight: 680;
  transition: color var(--duration-fast) ease, background var(--duration-fast) ease;
}

.lens-switcher button:hover {
  color: var(--color-ink);
  background: var(--color-surface-deep);
}

.lens-switcher button[aria-pressed="true"] {
  color: var(--color-surface);
  background: var(--color-blueprint);
}

.graph-stage {
  position: relative;
  min-height: 31.5rem;
  margin: 0.9rem 0.9rem 0;
  border: 1px solid color-mix(in srgb, var(--color-line) 74%, transparent);
  border-radius: calc(var(--radius-lg) - 0.25rem);
  overflow: clip;
}

.graph-stage::before,
.graph-stage::after {
  position: absolute;
  pointer-events: none;
  content: "";
  background: color-mix(in srgb, var(--color-line) 70%, transparent);
}

.graph-stage::before {
  inset: 3rem 1rem auto;
  height: 1px;
}

.graph-stage::after {
  inset: 1rem auto 1rem 3rem;
  width: 1px;
}

#heroEdges,
.graph-nodes {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-edge {
  fill: none;
  stroke: color-mix(in srgb, var(--color-blueprint) 44%, var(--color-line));
  stroke-width: 2;
  stroke-dasharray: 5 7;
  transition: d var(--duration-slow) var(--ease-field), opacity var(--duration-medium) ease;
}

.hero-edge.is-primary {
  stroke: var(--color-jade);
  stroke-width: 2.6;
  stroke-dasharray: none;
}

.hero-edge.is-action {
  stroke: var(--color-signal);
  stroke-width: 3.2;
  stroke-dasharray: 11 8;
  animation: edge-drift 2.4s linear infinite;
}

.graph-node {
  position: absolute;
  z-index: 2;
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-width: 5.2rem;
  min-height: 3.25rem;
  padding: 0.55rem 0.72rem;
  color: var(--color-ink);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--color-surface) 91%, transparent);
  box-shadow: 0 0.35rem 1rem rgb(19 35 31 / 0.08);
  transform: translate(-50%, -50%);
  transition:
    left var(--duration-slow) var(--ease-field),
    top var(--duration-slow) var(--ease-field),
    transform var(--duration-fast) var(--ease-field),
    border-color var(--duration-fast) ease,
    background var(--duration-fast) ease,
    box-shadow var(--duration-fast) ease;
}

.graph-node:hover {
  border-color: var(--color-blueprint);
  transform: translate(-50%, calc(-50% - 0.16rem));
  box-shadow: var(--shadow-control);
}

.graph-node[aria-pressed="true"] {
  color: var(--color-surface);
  border-color: var(--color-blueprint);
  background: var(--color-blueprint);
  box-shadow: 0 0 0 0.35rem color-mix(in srgb, var(--color-blueprint) 16%, transparent);
}

.graph-node small {
  margin-top: 0.18rem;
  color: var(--color-ink-soft);
  font-family: var(--font-utility);
  font-size: 0.49rem;
  letter-spacing: 0.1em;
}

.graph-node[aria-pressed="true"] small {
  color: var(--color-surface-deep);
}

.graph-node.node-kind-abstract {
  border-radius: var(--radius-full);
  border-style: dashed;
}

.graph-node.node-kind-instance {
  border-color: var(--color-jade);
}

.graph-node.node-kind-relation {
  min-width: 4.2rem;
  min-height: 2.7rem;
  border-radius: var(--radius-full);
  background: var(--color-surface-deep);
  font-family: var(--font-utility);
  font-size: 0.68rem;
}

.graph-node.node-kind-action {
  color: var(--color-surface);
  border-color: var(--color-signal);
  background: var(--color-signal);
}

.graph-node.node-kind-action small {
  color: var(--color-surface);
}

.graph-node.node-kind-policy {
  border: 2px double var(--color-focus);
  background: color-mix(in srgb, var(--color-surface) 82%, var(--color-focus));
}

.axis-label {
  position: absolute;
  color: var(--color-ink-soft);
  font-family: var(--font-utility);
  font-size: 0.53rem;
  letter-spacing: 0.09em;
}

.axis-label-x {
  right: 1rem;
  bottom: 0.5rem;
}

.axis-label-y {
  top: 1rem;
  left: 0.55rem;
  transform: rotate(-90deg) translateX(-100%);
  transform-origin: left top;
}

.graph-inspector {
  position: absolute;
  z-index: 4;
  right: 1.7rem;
  bottom: 1.5rem;
  width: min(21rem, calc(100% - 3.4rem));
  min-height: 8.4rem;
  padding: 1rem 1.1rem;
  border-left: 0.2rem solid var(--color-signal);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: color-mix(in srgb, var(--color-surface) 94%, transparent);
  box-shadow: var(--shadow-control);
  backdrop-filter: blur(0.8rem);
}

.graph-inspector .utility-label {
  margin-bottom: 0.45rem;
  font-size: 0.58rem;
}

.graph-inspector h2 {
  margin-bottom: 0.4rem;
  font-family: var(--font-display);
  font-size: 1.55rem;
}

.graph-inspector p:last-child {
  margin-bottom: 0;
  color: var(--color-ink-soft);
  font-size: 0.79rem;
  line-height: 1.62;
}

.figure-note {
  max-width: 35rem;
  margin: 1rem 0 0 auto;
  color: var(--color-ink-soft);
  font-size: 0.75rem;
  text-align: right;
}

.definition-ribbon {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 15rem;
  padding: 3rem var(--page-gutter);
  color: var(--color-surface);
  background: var(--color-ink);
  overflow: clip;
}

.definition-ribbon::before {
  position: absolute;
  width: 42rem;
  height: 42rem;
  border: 1px solid rgb(248 250 247 / 0.12);
  border-radius: 50%;
  content: "";
}

.definition-ribbon p {
  position: relative;
  max-width: 54rem;
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3.2vw, 2.75rem);
  line-height: 1.45;
  text-align: center;
}

.definition-ribbon span {
  display: inline-flex;
  margin-right: 0.2em;
  padding: 0.06em 0.32em 0.1em;
  color: var(--color-ink);
  background: var(--color-amber);
  border-radius: 0.15em;
}

.definition-ribbon b {
  color: var(--color-amber);
  font-weight: 700;
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(18rem, 0.55fr);
  gap: 3rem;
  align-items: end;
  margin-bottom: 4rem;
}

.section-heading .eyebrow {
  grid-column: 1 / -1;
  margin-bottom: -1rem;
}

.section-heading h2 {
  max-width: 13em;
  margin-bottom: 0;
  font-family: var(--font-display);
  font-size: clamp(2.45rem, 5vw, 4.8rem);
  font-weight: 680;
  letter-spacing: -0.045em;
}

.section-heading > p:last-child {
  margin-bottom: 0.25rem;
  color: var(--color-ink-soft);
}

.lens-essays {
  border-top: 1px solid var(--color-ink);
}

.lens-essay {
  display: grid;
  grid-template-columns: 8rem minmax(0, 1fr);
  min-height: 19rem;
  padding: 2.3rem 0;
  border-bottom: 1px solid var(--color-line);
}

.lens-essay > div:last-child {
  display: grid;
  grid-template-columns: minmax(16rem, 0.9fr) minmax(16rem, 0.75fr);
  gap: 1.5rem 3rem;
  align-content: start;
}

.essay-index {
  color: var(--color-line);
  font-family: var(--font-display);
  font-size: 4.5rem;
  line-height: 0.9;
}

.lens-essay .utility-label {
  grid-column: 1 / -1;
  margin-bottom: 0;
}

.lens-essay h3 {
  margin-bottom: 0;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3vw, 2.55rem);
  font-weight: 680;
}

.lens-essay h3 + p {
  margin-bottom: 0;
  color: var(--color-ink-soft);
}

.margin-note {
  grid-column: 2;
  max-width: 34rem;
  margin: 0;
  padding-top: 1rem;
  color: var(--color-blueprint);
  border-top: 1px solid var(--color-blueprint);
  font-size: 0.8rem;
}

.operations-essay {
  border-bottom-color: var(--color-ink);
}

.operations-essay .essay-index {
  color: var(--color-signal);
}

.concept-ladder {
  display: grid;
  grid-template-columns: minmax(18rem, 0.62fr) minmax(0, 1.38fr);
  gap: clamp(2rem, 6vw, 5rem);
  margin-top: 7rem;
  padding: clamp(1.5rem, 4vw, 3.2rem);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  background: var(--color-surface-deep);
}

.ladder-intro h3 {
  margin-bottom: 1.1rem;
  font-family: var(--font-display);
  font-size: clamp(2rem, 3.6vw, 3.35rem);
}

.ladder-intro > p:last-child {
  color: var(--color-ink-soft);
}

.ladder-workbench {
  min-width: 0;
}

.ladder-controls {
  display: flex;
  gap: 0.35rem;
  margin-bottom: 0.8rem;
  padding-bottom: 0.35rem;
  overflow-x: auto;
  scrollbar-gutter: stable;
}

.ladder-controls button {
  flex: 1 0 auto;
  min-width: 6rem;
  min-height: 3rem;
  padding: 0.55rem 0.75rem;
  color: var(--color-ink-soft);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  background: transparent;
  font-size: 0.76rem;
  font-weight: 700;
  text-align: left;
  transition: color var(--duration-fast) ease, border-color var(--duration-fast) ease, background var(--duration-fast) ease;
}

.ladder-controls button span {
  display: block;
  color: var(--color-jade);
  font-family: var(--font-utility);
  font-size: 0.55rem;
}

.ladder-controls button:hover {
  color: var(--color-ink);
  border-color: var(--color-line);
  background: color-mix(in srgb, var(--color-surface) 55%, transparent);
}

.ladder-controls button[aria-pressed="true"] {
  color: var(--color-surface);
  border-color: var(--color-ink);
  background: var(--color-ink);
}

.ladder-controls button[aria-pressed="true"] span {
  color: var(--color-amber);
}

.ladder-display {
  display: grid;
  grid-template-columns: minmax(12rem, 0.75fr) minmax(14rem, 1.25fr);
  gap: 1.5rem;
  align-items: center;
  min-height: 20rem;
  padding: 1.5rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: var(--color-surface);
}

.ladder-display h4 {
  margin-bottom: 0.75rem;
  font-family: var(--font-display);
  font-size: clamp(1.65rem, 3vw, 2.55rem);
}

.ladder-display p {
  margin-bottom: 0.55rem;
  color: var(--color-ink-soft);
}

.ladder-display .ladder-limit {
  margin-top: 1rem;
  padding-top: 0.85rem;
  color: var(--color-danger);
  border-top: 1px solid var(--color-line);
  font-size: 0.8rem;
}

.ladder-visual {
  position: relative;
  aspect-ratio: 1;
  width: min(100%, 15rem);
  margin-inline: auto;
  border: 1px dashed var(--color-line);
  border-radius: 50%;
  transition: border-color var(--duration-medium) ease, background var(--duration-medium) ease;
}

.visual-node {
  position: absolute;
  z-index: 2;
  width: 2.3rem;
  height: 2.3rem;
  border: 0.22rem solid var(--color-surface);
  border-radius: 50%;
  background: var(--color-blueprint);
  box-shadow: 0 0 0 1px var(--color-blueprint);
  transition: transform var(--duration-slow) var(--ease-field), background var(--duration-medium) ease;
}

.node-a {
  top: 16%;
  left: 42%;
}

.node-b {
  top: 59%;
  left: 19%;
  background: var(--color-jade);
  box-shadow: 0 0 0 1px var(--color-jade);
}

.node-c {
  top: 59%;
  right: 18%;
  background: var(--color-amber);
  box-shadow: 0 0 0 1px var(--color-amber);
}

.visual-link {
  position: absolute;
  z-index: 1;
  height: 0.12rem;
  background: var(--color-line);
  transform-origin: left center;
  transition: background var(--duration-medium) ease, height var(--duration-medium) ease;
}

.link-a {
  width: 44%;
  top: 36%;
  left: 45%;
  transform: rotate(57deg);
}

.link-b {
  width: 44%;
  top: 66%;
  left: 27%;
  transform: rotate(-3deg);
}

.visual-action {
  position: absolute;
  z-index: 3;
  right: 13%;
  bottom: 11%;
  padding: 0.35rem 0.55rem;
  color: var(--color-surface);
  border-radius: var(--radius-sm);
  background: var(--color-signal);
  font-family: var(--font-utility);
  font-size: 0.52rem;
  opacity: 0;
  transform: translateY(0.7rem);
  transition: opacity var(--duration-medium) ease, transform var(--duration-medium) var(--ease-field);
}

.ladder-visual[data-level="taxonomy"] .node-b,
.ladder-visual[data-level="taxonomy"] .node-c {
  transform: scale(0.82);
}

.ladder-visual[data-level="schema"] {
  border-radius: var(--radius-sm);
}

.ladder-visual[data-level="schema"] .visual-node {
  border-radius: var(--radius-sm);
}

.ladder-visual[data-level="graph"] .visual-link,
.ladder-visual[data-level="twin"] .visual-link,
.ladder-visual[data-level="operational"] .visual-link {
  height: 0.2rem;
  background: var(--color-jade);
}

.ladder-visual[data-level="twin"] {
  border-color: var(--color-blueprint);
  background: radial-gradient(circle, color-mix(in srgb, var(--color-blueprint) 8%, transparent), transparent 66%);
}

.ladder-visual[data-level="twin"] .visual-node {
  animation: node-breathe 2.4s ease-in-out infinite;
}

.ladder-visual[data-level="operational"] {
  border-color: var(--color-signal);
}

.ladder-visual[data-level="operational"] .visual-action {
  opacity: 1;
  transform: translateY(0);
}

.anatomy {
  padding-top: calc(var(--space-section) + 1rem);
}

.anatomy-grid {
  display: grid;
  grid-template-columns: minmax(16rem, 0.38fr) minmax(0, 1.62fr);
  gap: 1rem;
}

.anatomy-controls {
  display: grid;
  gap: 0.55rem;
}

.anatomy-controls button {
  display: grid;
  grid-template-columns: 3rem 1fr;
  grid-template-rows: auto auto;
  min-height: 5.5rem;
  padding: 0.9rem 1rem;
  color: var(--color-ink);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--color-surface) 58%, transparent);
  text-align: left;
  transition: border-color var(--duration-fast) ease, background var(--duration-fast) ease, transform var(--duration-fast) var(--ease-field);
}

.anatomy-controls button:hover {
  border-color: var(--color-blueprint);
  transform: translateX(0.18rem);
}

.anatomy-controls button[aria-pressed="true"] {
  color: var(--color-surface);
  border-color: var(--color-ink);
  background: var(--color-ink);
}

.anatomy-controls button > span {
  grid-row: 1 / span 2;
  align-self: center;
  color: var(--color-signal);
  font-family: var(--font-display);
  font-size: 1.35rem;
}

.anatomy-controls button strong {
  font-size: 0.95rem;
}

.anatomy-controls button small {
  color: var(--color-ink-soft);
  font-family: var(--font-utility);
  font-size: 0.53rem;
  line-height: 1.45;
}

.anatomy-controls button[aria-pressed="true"] small {
  color: var(--color-surface-deep);
}

.sentence-board {
  position: relative;
  display: grid;
  grid-template-rows: auto auto 1fr;
  min-height: 31rem;
  padding: clamp(1.4rem, 4vw, 3rem);
  color: var(--color-surface);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(circle at 82% 20%, rgb(240 182 75 / 0.13), transparent 22%),
    var(--color-ink);
  overflow: clip;
}

.sentence-board::after {
  position: absolute;
  right: -5rem;
  bottom: -9rem;
  width: 24rem;
  height: 24rem;
  border: 1px solid rgb(248 250 247 / 0.12);
  border-radius: 50%;
  content: "";
}

.sentence-board > .utility-label {
  color: var(--color-amber);
}

.enterprise-sentence {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  max-width: 52rem;
  margin: 1.25rem 0 2.6rem;
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 3.2vw, 2.8rem);
  line-height: 1.4;
}

.enterprise-sentence span {
  padding: 0.08em 0.2em 0.14em;
  color: color-mix(in srgb, var(--color-surface) 58%, transparent);
  border-bottom: 1px solid rgb(248 250 247 / 0.15);
  transition: color var(--duration-medium) ease, background var(--duration-medium) ease, transform var(--duration-medium) var(--ease-field);
}

.enterprise-sentence span.is-active {
  color: var(--color-ink);
  background: var(--color-amber);
  border-color: var(--color-amber);
  transform: translateY(-0.12em);
}

.anatomy-explainer {
  position: relative;
  z-index: 1;
  align-self: end;
  max-width: 43rem;
  padding-top: 1.4rem;
  border-top: 1px solid rgb(248 250 247 / 0.25);
}

.anatomy-explainer .utility-label {
  color: var(--color-amber);
}

.anatomy-explainer h3 {
  margin-bottom: 0.7rem;
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 2.6vw, 2.15rem);
}

.anatomy-explainer p {
  color: var(--color-surface-deep);
}

.anatomy-explainer code {
  display: inline-block;
  max-width: 100%;
  padding: 0.55rem 0.75rem;
  color: var(--color-amber);
  border: 1px solid rgb(240 182 75 / 0.35);
  border-radius: var(--radius-sm);
  overflow-wrap: anywhere;
}

.core-claim {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.5rem;
  align-items: center;
  margin-top: 1rem;
  padding: 1.6rem clamp(1.3rem, 4vw, 3rem);
  border: 1px solid var(--color-signal);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--color-signal) 8%, var(--color-surface));
}

.claim-mark {
  color: var(--color-signal);
  font-family: var(--font-display);
  font-size: 4rem;
  line-height: 1;
}

.core-claim p {
  margin-bottom: 0.45rem;
  color: var(--color-signal);
}

.core-claim h3 {
  max-width: 35em;
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 2.6vw, 2.2rem);
}

.simulation {
  width: min(100% - (var(--page-gutter) * 1.15), 88rem);
}

.simulation-heading {
  grid-template-columns: minmax(0, 1fr) minmax(20rem, 0.7fr);
}

.simulation-heading .eyebrow {
  grid-column: auto;
  margin-bottom: 0.8rem;
}

.simulation-heading > div h2 {
  margin-bottom: 0;
}

.scenario-shell {
  border: 1px solid var(--color-ink);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  box-shadow: var(--shadow-float);
  overflow: clip;
}

.scenario-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 4.75rem;
  padding: 0.85rem 1.1rem;
  color: var(--color-surface);
  background: var(--color-ink);
}

.scenario-topbar > div:first-child {
  display: grid;
  gap: 0.1rem;
}

.scenario-state {
  font-size: 0.88rem;
  font-weight: 760;
}

.scenario-caption {
  color: var(--color-surface-deep);
  font-size: 0.67rem;
}

.role-switcher {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.25rem;
  border: 1px solid rgb(248 250 247 / 0.22);
  border-radius: var(--radius-full);
}

.role-switcher > span {
  margin-inline: 0.5rem 0.35rem;
  color: var(--color-surface-deep);
  font-size: 0.63rem;
}

.role-switcher button {
  min-height: 2.1rem;
  padding: 0.4rem 0.7rem;
  color: var(--color-surface-deep);
  border: 0;
  border-radius: var(--radius-full);
  background: transparent;
  font-size: 0.68rem;
  font-weight: 680;
}

.role-switcher button:hover {
  color: var(--color-surface);
  background: rgb(248 250 247 / 0.1);
}

.role-switcher button[aria-pressed="true"] {
  color: var(--color-ink);
  background: var(--color-amber);
}

.scenario-main {
  display: grid;
  grid-template-columns: minmax(0, 1.52fr) minmax(20rem, 0.48fr);
  min-height: 42rem;
}

.scenario-map-wrap {
  min-width: 0;
  padding: 1.1rem;
  border-right: 1px solid var(--color-line);
  background:
    linear-gradient(90deg, rgb(33 79 112 / 0.035) 1px, transparent 1px) 0 0 / 2.1rem 2.1rem,
    linear-gradient(rgb(33 79 112 / 0.035) 1px, transparent 1px) 0 0 / 2.1rem 2.1rem,
    var(--color-paper);
}

.scenario-map {
  width: 100%;
  min-height: 31rem;
}

.scenario-map marker path {
  fill: var(--color-line);
}

.sim-edges path {
  fill: none;
  stroke: var(--color-line);
  stroke-width: 2.5;
  marker-end: url(#arrow);
  transition: stroke var(--duration-medium) ease, stroke-width var(--duration-medium) ease, opacity var(--duration-medium) ease;
}

.sim-edges .option-edge {
  stroke-dasharray: 6 7;
  opacity: 0.23;
}

.sim-edges path.is-risk {
  stroke: var(--color-danger);
  stroke-width: 4;
  stroke-dasharray: 11 8;
  animation: edge-drift 1.05s linear infinite;
}

.sim-edges path.is-action {
  stroke: var(--color-signal);
  stroke-width: 5;
  stroke-dasharray: 12 8;
  opacity: 1;
  animation: edge-drift 0.9s linear infinite;
}

.sim-edges path.is-resolved {
  stroke: var(--color-jade);
  stroke-width: 4.5;
  stroke-dasharray: none;
  opacity: 1;
}

.sim-node circle,
.sim-node rect {
  fill: var(--color-surface);
  stroke: var(--color-line);
  stroke-width: 2;
  transition: fill var(--duration-medium) ease, stroke var(--duration-medium) ease, stroke-width var(--duration-medium) ease;
}

.sim-node text {
  fill: var(--color-ink);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 720;
  pointer-events: none;
}

.sim-node .node-meta {
  fill: var(--color-ink-soft);
  font-family: var(--font-utility);
  font-size: 8px;
  font-weight: 520;
  letter-spacing: 0.09em;
}

.sim-node.is-risk circle,
.sim-node.is-risk rect {
  fill: color-mix(in srgb, var(--color-danger) 12%, var(--color-surface));
  stroke: var(--color-danger);
  stroke-width: 4;
  animation: risk-pulse 1.45s ease-in-out infinite;
}

.sim-node.is-action circle,
.sim-node.is-action rect {
  fill: color-mix(in srgb, var(--color-signal) 14%, var(--color-surface));
  stroke: var(--color-signal);
  stroke-width: 4;
}

.sim-node.is-resolved circle,
.sim-node.is-resolved rect {
  fill: color-mix(in srgb, var(--color-jade) 14%, var(--color-surface));
  stroke: var(--color-jade);
  stroke-width: 4;
}

.sim-key text {
  fill: var(--color-ink-soft);
  font-family: var(--font-utility);
  font-size: 9px;
}

.sim-key .key-normal {
  fill: var(--color-line);
}

.sim-key .key-risk {
  fill: var(--color-danger);
}

.sim-key .key-action {
  fill: var(--color-signal);
}

.scenario-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.65rem;
  margin-top: 0.7rem;
}

.scenario-metrics > div {
  display: grid;
  grid-template-columns: auto 1fr;
  min-height: 6.8rem;
  padding: 0.8rem 0.9rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--color-surface) 83%, transparent);
}

.scenario-metrics span {
  grid-column: 1 / -1;
  color: var(--color-ink-soft);
  font-size: 0.72rem;
}

.scenario-metrics strong {
  align-self: end;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3vw, 2.5rem);
  line-height: 1;
}

.scenario-metrics small {
  align-self: end;
  margin-left: 0.4rem;
  color: var(--color-ink-soft);
  font-size: 0.6rem;
}

.scenario-metrics [data-restricted="true"] strong {
  font-family: var(--font-body);
  font-size: 1.1rem;
  letter-spacing: 0.08em;
}

.scenario-console {
  display: grid;
  align-content: start;
  background: var(--color-surface);
}

.console-step {
  padding: 1.35rem;
  border-bottom: 1px solid var(--color-line);
}

.console-step > span {
  display: block;
  margin-bottom: 0.55rem;
  color: var(--color-blueprint);
  font-family: var(--font-utility);
  font-size: 0.58rem;
  font-weight: 680;
  letter-spacing: 0.11em;
}

.console-step h3 {
  margin-bottom: 0.65rem;
  font-family: var(--font-display);
  font-size: 1.45rem;
}

.console-step p {
  color: var(--color-ink-soft);
  font-size: 0.78rem;
  line-height: 1.65;
}

.console-step > .button {
  width: 100%;
}

.plan-list {
  display: grid;
  gap: 0.48rem;
}

.plan-list button {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 0.65rem;
  align-items: center;
  width: 100%;
  min-height: 4.3rem;
  padding: 0.68rem 0.72rem;
  color: var(--color-ink);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  text-align: left;
  transition: border-color var(--duration-fast) ease, background var(--duration-fast) ease, transform var(--duration-fast) var(--ease-field);
}

.plan-list button:not(:disabled):hover {
  border-color: var(--color-blueprint);
  transform: translateX(0.12rem);
}

.plan-list button[aria-pressed="true"] {
  border-color: var(--color-signal);
  background: color-mix(in srgb, var(--color-signal) 8%, var(--color-surface));
}

.plan-radio {
  width: 1rem;
  height: 1rem;
  border: 1px solid var(--color-line);
  border-radius: 50%;
  background: var(--color-surface);
  box-shadow: inset 0 0 0 0.22rem var(--color-surface);
}

.plan-list button[aria-pressed="true"] .plan-radio {
  border-color: var(--color-signal);
  background: var(--color-signal);
}

.plan-list button span:nth-child(2) {
  display: grid;
}

.plan-list button strong {
  font-size: 0.82rem;
}

.plan-list button small {
  margin-top: 0.1rem;
  color: var(--color-ink-soft);
  font-size: 0.61rem;
  line-height: 1.4;
}

.plan-list button b {
  color: var(--color-blueprint);
  font-family: var(--font-utility);
  font-size: 0.52rem;
  font-weight: 680;
  white-space: nowrap;
}

.execution-step {
  border-bottom: 0;
}

.execution-summary {
  min-height: 6.2rem;
  margin-bottom: 0.75rem;
  padding: 0.72rem 0.78rem;
  border-left: 0.2rem solid var(--color-line);
  background: var(--color-paper);
}

.execution-summary p {
  margin: 0;
}

.execution-summary strong {
  color: var(--color-ink);
}

.reset-button {
  margin-top: 0.55rem;
}

.decision-log {
  display: grid;
  grid-template-columns: 11rem 1fr;
  gap: 1rem;
  min-height: 8.5rem;
  padding: 1.15rem 1.3rem;
  color: var(--color-surface);
  background: var(--color-blueprint);
}

.decision-log .utility-label {
  color: var(--color-amber);
}

.decision-log ol {
  display: grid;
  gap: 0.42rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.decision-log li {
  display: grid;
  grid-template-columns: 3.4rem 1fr;
  gap: 0.6rem;
  align-items: start;
  padding-bottom: 0.42rem;
  border-bottom: 1px solid rgb(248 250 247 / 0.16);
  font-size: 0.73rem;
  line-height: 1.55;
}

.decision-log time {
  color: var(--color-amber);
  font-family: var(--font-utility);
  font-size: 0.6rem;
}

.loop-explainer {
  display: grid;
  grid-template-columns: repeat(9, auto);
  gap: 0.65rem;
  align-items: center;
  justify-content: center;
  margin-top: 2rem;
}

.loop-explainer div {
  display: grid;
  gap: 0.2rem;
  min-width: 7rem;
  padding: 0.8rem;
  border-top: 2px solid var(--color-blueprint);
}

.loop-explainer div:nth-of-type(3) {
  border-color: var(--color-signal);
}

.loop-explainer div:nth-of-type(4) {
  border-color: var(--color-focus);
}

.loop-explainer div:nth-of-type(5) {
  border-color: var(--color-jade);
}

.loop-explainer span {
  color: var(--color-blueprint);
  font-family: var(--font-utility);
  font-size: 0.56rem;
  font-weight: 700;
}

.loop-explainer b {
  font-size: 0.73rem;
}

.loop-explainer i {
  color: var(--color-line);
  font-style: normal;
}

.playbook {
  border-top: 1px solid var(--color-ink);
}

.playbook details {
  border-bottom: 1px solid var(--color-line);
}

.playbook summary {
  display: grid;
  grid-template-columns: 5rem minmax(0, 1fr) minmax(12rem, 0.55fr);
  gap: 1rem;
  align-items: center;
  min-height: 6.1rem;
  padding: 1rem 0.5rem;
  list-style: none;
  transition: color var(--duration-fast) ease, padding var(--duration-fast) var(--ease-field);
}

.playbook summary::-webkit-details-marker {
  display: none;
}

.playbook summary:hover {
  color: var(--color-blueprint);
  padding-inline: 0.85rem 0.15rem;
}

.playbook summary span {
  color: var(--color-signal);
  font-family: var(--font-utility);
  font-size: 0.68rem;
}

.playbook summary strong {
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 2.3vw, 1.85rem);
}

.playbook summary small {
  color: var(--color-ink-soft);
  font-family: var(--font-utility);
  font-size: 0.65rem;
}

.playbook summary::after {
  grid-column: 4;
  content: "+";
  font-family: var(--font-utility);
  font-size: 1.25rem;
}

.playbook details[open] summary::after {
  content: "−";
}

.playbook details[open] summary {
  color: var(--color-blueprint);
}

.playbook details > div {
  display: grid;
  grid-template-columns: 5rem minmax(0, 1fr) minmax(12rem, 0.55fr) auto;
  gap: 1rem;
  padding: 0 0.5rem 2rem;
}

.playbook details > div p {
  grid-column: 2;
  max-width: 48rem;
  margin: 0;
  color: var(--color-ink-soft);
}

.playbook details > div code {
  grid-column: 3 / span 2;
  align-self: start;
  padding: 0.65rem 0.8rem;
  color: var(--color-blueprint);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  overflow-wrap: anywhere;
}

.anti-patterns {
  display: grid;
  grid-template-columns: minmax(16rem, 0.48fr) minmax(0, 1.52fr);
  gap: clamp(2rem, 6vw, 5rem);
  margin-top: 7rem;
}

.anti-patterns-intro h3 {
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 4vw, 3.6rem);
}

.anti-pattern-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--color-ink);
}

.anti-pattern-grid article {
  min-height: 11.5rem;
  padding: 1.35rem 1.1rem;
  border-right: 1px solid var(--color-line);
  border-bottom: 1px solid var(--color-line);
}

.anti-pattern-grid article:nth-child(even) {
  border-right: 0;
}

.anti-pattern-grid span {
  color: var(--color-danger);
  font-family: var(--font-utility);
  font-size: 0.62rem;
}

.anti-pattern-grid h4 {
  margin: 1.05rem 0 0.5rem;
  font-family: var(--font-display);
  font-size: 1.5rem;
}

.anti-pattern-grid p {
  margin-bottom: 0;
  color: var(--color-ink-soft);
  font-size: 0.82rem;
}

.case-ledger {
  border-top: 1px solid var(--color-ink);
}

.case {
  display: grid;
  grid-template-columns: minmax(12rem, 0.6fr) minmax(14rem, 0.78fr) minmax(18rem, 1.2fr) auto;
  gap: 2rem;
  align-items: center;
  min-height: 16rem;
  padding: 2rem 0;
  border-bottom: 1px solid var(--color-line);
}

.case-label {
  display: grid;
  gap: 0.45rem;
}

.case-label span {
  color: var(--color-blueprint);
  font-family: var(--font-utility);
  font-size: 0.56rem;
  letter-spacing: 0.1em;
}

.case-label b {
  font-family: var(--font-display);
  font-size: 1.75rem;
}

.case-metric {
  display: grid;
}

.case-metric strong {
  color: var(--color-signal);
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 5vw, 5.4rem);
  font-weight: 700;
  letter-spacing: -0.05em;
  line-height: 0.9;
}

.case-metric span {
  margin-top: 0.55rem;
  color: var(--color-ink-soft);
  font-size: 0.7rem;
}

.case > p {
  margin: 0;
  color: var(--color-ink-soft);
}

.case > a {
  font-size: 0.73rem;
  font-weight: 700;
  white-space: nowrap;
}

.knowledge-check {
  display: grid;
  grid-template-columns: minmax(18rem, 0.65fr) minmax(0, 1.35fr);
  gap: clamp(2rem, 7vw, 6rem);
  align-items: start;
}

.check-intro {
  position: sticky;
  top: calc(var(--header-height) + 2rem);
}

.check-intro h2 {
  margin-bottom: 1.1rem;
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 4.5vw, 4.1rem);
}

.check-intro > p:not(.eyebrow):not(.utility-label) {
  color: var(--color-ink-soft);
}

.check-progress {
  width: min(100%, 23rem);
  height: 0.38rem;
  margin: 2rem 0 0.7rem;
  border-radius: var(--radius-full);
  background: var(--color-surface-deep);
  overflow: clip;
}

.check-progress span {
  display: block;
  width: 33.33%;
  height: 100%;
  border-radius: inherit;
  background: var(--color-signal);
  transition: width var(--duration-medium) var(--ease-field);
}

.quiz-card {
  min-height: 31rem;
  padding: clamp(1.5rem, 5vw, 3.8rem);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  box-shadow: var(--shadow-float);
}

.quiz-card h3 {
  max-width: 24em;
  margin-bottom: 2rem;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.5vw, 2.8rem);
}

.quiz-options {
  display: grid;
  gap: 0.65rem;
}

.quiz-options button {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.8rem;
  align-items: center;
  min-height: 4.1rem;
  padding: 0.75rem 0.9rem;
  color: var(--color-ink);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  text-align: left;
  transition: border-color var(--duration-fast) ease, background var(--duration-fast) ease, transform var(--duration-fast) var(--ease-field);
}

.quiz-options button::before {
  display: grid;
  place-items: center;
  width: 1.75rem;
  height: 1.75rem;
  content: attr(data-option-label);
  color: var(--color-blueprint);
  border: 1px solid var(--color-line);
  border-radius: 50%;
  font-family: var(--font-utility);
  font-size: 0.65rem;
}

.quiz-options button:not(:disabled):hover {
  border-color: var(--color-blueprint);
  transform: translateX(0.18rem);
}

.quiz-options button.is-selected {
  border-color: var(--color-blueprint);
  background: color-mix(in srgb, var(--color-blueprint) 7%, var(--color-surface));
}

.quiz-options button.is-correct {
  border-color: var(--color-jade);
  background: color-mix(in srgb, var(--color-jade) 9%, var(--color-surface));
}

.quiz-options button.is-correct::before {
  color: var(--color-surface);
  border-color: var(--color-jade);
  background: var(--color-jade);
}

.quiz-options button.is-wrong {
  border-color: var(--color-danger);
  background: color-mix(in srgb, var(--color-danger) 7%, var(--color-surface));
}

.quiz-feedback {
  display: grid;
  align-items: center;
  min-height: 6.8rem;
  margin: 1rem 0;
  padding: 0.85rem 1rem;
  border-left: 0.22rem solid var(--color-line);
  background: var(--color-paper);
}

.quiz-feedback p {
  margin: 0;
  color: var(--color-ink-soft);
}

.quiz-feedback strong {
  color: var(--color-ink);
}

.source-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.source-columns > div {
  padding: clamp(1.3rem, 4vw, 2.5rem);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--color-surface) 72%, transparent);
}

.source-columns h3 {
  margin-bottom: 1.4rem;
  font-family: var(--font-display);
  font-size: 1.7rem;
}

.source-columns ul {
  display: grid;
  gap: 0.65rem;
  margin: 0;
  padding-left: 1.1rem;
}

.source-columns li::marker {
  color: var(--color-signal);
}

.source-columns a {
  font-size: 0.8rem;
  overflow-wrap: anywhere;
}

.boundary-notes {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin-top: 4rem;
  border: 1px solid var(--color-ink);
  background: var(--color-ink);
}

.boundary-notes article {
  min-height: 14rem;
  padding: 1.5rem;
  background: var(--color-surface);
}

.boundary-notes span {
  color: var(--color-signal);
  font-family: var(--font-utility);
  font-size: 0.62rem;
}

.boundary-notes h3 {
  margin: 1.45rem 0 0.7rem;
  font-family: var(--font-display);
  font-size: 1.5rem;
}

.boundary-notes p {
  margin: 0;
  color: var(--color-ink-soft);
  font-size: 0.82rem;
}

.site-footer {
  display: grid;
  grid-template-columns: 1fr minmax(18rem, 1.4fr) auto;
  gap: 2rem;
  align-items: end;
  padding: 3rem var(--page-gutter);
  color: var(--color-surface);
  background: var(--color-ink);
}

.site-footer strong {
  font-family: var(--font-display);
  font-size: 1.8rem;
}

.site-footer p {
  margin: 0;
  color: var(--color-surface-deep);
  font-size: 0.73rem;
}

.site-footer a {
  color: var(--color-amber);
  font-size: 0.76rem;
  font-weight: 720;
}

.noscript-message {
  position: fixed;
  z-index: 999;
  right: 1rem;
  bottom: 1rem;
  max-width: 28rem;
  padding: 1rem;
  color: var(--color-surface);
  border-radius: var(--radius-md);
  background: var(--color-danger);
  box-shadow: var(--shadow-float);
}

.js [data-reveal] {
  opacity: 0;
  transform: translateY(1.2rem);
  transition: opacity 720ms var(--ease-field), transform 720ms var(--ease-field);
}

.js [data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

@keyframes edge-drift {
  to {
    stroke-dashoffset: -38;
  }
}

@keyframes risk-pulse {
  0%,
  100% {
    filter: drop-shadow(0 0 0 rgb(179 61 61 / 0));
  }
  50% {
    filter: drop-shadow(0 0 0.65rem rgb(179 61 61 / 0.34));
  }
}

@keyframes node-breathe {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.09);
  }
}

@media (max-width: 72rem) {
  .chapter-nav a:nth-child(2),
  .chapter-nav a:nth-child(4) {
    display: none;
  }

  .hero {
    grid-template-columns: minmax(0, 0.7fr) minmax(30rem, 1.3fr);
    gap: 2.5rem;
  }

  .hero h1 {
    font-size: clamp(3rem, 7.3vw, 5.3rem);
  }

  .concept-ladder {
    grid-template-columns: 1fr;
  }

  .scenario-main {
    grid-template-columns: minmax(0, 1.35fr) minmax(18rem, 0.65fr);
  }

  .role-switcher > span {
    display: none;
  }

  .loop-explainer {
    grid-template-columns: repeat(5, 1fr);
  }

  .loop-explainer i {
    display: none;
  }

  .case {
    grid-template-columns: minmax(10rem, 0.58fr) minmax(12rem, 0.72fr) minmax(18rem, 1.3fr);
  }

  .case > a {
    grid-column: 3;
  }
}

@media (max-width: 58rem) {
  :root {
    --space-section: 5rem;
  }

  .site-header {
    align-items: flex-start;
  }

  .chapter-nav {
    max-width: 58vw;
    overflow-x: auto;
    scrollbar-gutter: stable;
  }

  .chapter-nav a {
    flex: 0 0 auto;
  }

  .chapter-nav a:nth-child(2),
  .chapter-nav a:nth-child(4) {
    display: block;
  }

  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-top: 5.5rem;
  }

  .hero-copy {
    max-width: 47rem;
  }

  .hero h1 {
    max-width: 10em;
  }

  .hero-graph-wrap {
    width: min(100%, 44rem);
    margin-inline: auto;
  }

  .section-heading,
  .simulation-heading {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .section-heading .eyebrow {
    margin-bottom: -0.35rem;
  }

  .lens-essay {
    grid-template-columns: 5rem minmax(0, 1fr);
  }

  .lens-essay > div:last-child {
    grid-template-columns: 1fr;
  }

  .margin-note {
    grid-column: 1;
  }

  .ladder-display {
    grid-template-columns: minmax(9rem, 0.55fr) minmax(13rem, 1.45fr);
  }

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

  .anatomy-controls {
    grid-template-columns: repeat(5, minmax(8rem, 1fr));
    padding-bottom: 0.35rem;
    overflow-x: auto;
    scrollbar-gutter: stable;
  }

  .anatomy-controls button {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto;
    min-height: 7rem;
  }

  .anatomy-controls button > span {
    grid-row: auto;
  }

  .scenario-topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .role-switcher {
    max-width: 100%;
    overflow-x: auto;
  }

  .scenario-main {
    grid-template-columns: 1fr;
  }

  .scenario-map-wrap {
    border-right: 0;
    border-bottom: 1px solid var(--color-line);
  }

  .scenario-map {
    min-height: auto;
  }

  .scenario-console {
    grid-template-columns: repeat(3, minmax(16rem, 1fr));
    overflow-x: auto;
    scrollbar-gutter: stable;
  }

  .console-step {
    min-height: 25rem;
    border-right: 1px solid var(--color-line);
    border-bottom: 0;
  }

  .decision-log {
    grid-template-columns: 1fr;
  }

  .anti-patterns {
    grid-template-columns: 1fr;
  }

  .case {
    grid-template-columns: minmax(10rem, 0.6fr) minmax(12rem, 0.75fr) minmax(0, 1.25fr);
    gap: 1.2rem;
  }

  .knowledge-check {
    grid-template-columns: 1fr;
  }

  .check-intro {
    position: static;
  }

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

  .site-footer {
    grid-template-columns: 1fr 1fr;
  }

  .site-footer > a {
    grid-column: 2;
    justify-self: end;
  }
}

@media (max-width: 40rem) {
  :root {
    --header-height: 4rem;
    --space-section: 4.4rem;
  }

  body {
    font-size: 0.98rem;
  }

  .site-header {
    padding-block: 0.55rem;
  }

  .brand small,
  .chapter-nav a:nth-child(n + 4) {
    display: none;
  }

  .chapter-nav {
    max-width: 47vw;
  }

  .hero {
    padding-top: 4.3rem;
  }

  .hero h1 {
    font-size: clamp(3rem, 16.5vw, 5rem);
  }

  .hero-legend {
    grid-template-columns: 1fr;
  }

  .graph-card {
    min-height: 39rem;
    border-radius: var(--radius-md);
  }

  .graph-toolbar {
    align-items: flex-start;
  }

  .graph-toolbar .utility-label {
    max-width: 9rem;
  }

  .lens-switcher {
    width: calc(100% - 3rem);
  }

  .lens-switcher button {
    flex: 1;
    min-width: 0;
  }

  .graph-stage {
    min-height: 29.5rem;
  }

  .graph-node {
    min-width: 4.6rem;
    min-height: 3rem;
    padding: 0.45rem 0.55rem;
    font-size: 0.78rem;
  }

  .graph-inspector {
    right: 1.15rem;
    bottom: 1rem;
    width: calc(100% - 2.3rem);
    min-height: 8.8rem;
  }

  .figure-note {
    text-align: left;
  }

  .lens-essay {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .essay-index {
    font-size: 3rem;
  }

  .concept-ladder {
    padding: 1rem;
  }

  .ladder-display {
    grid-template-columns: 1fr;
  }

  .ladder-visual {
    width: 11rem;
  }

  .sentence-board {
    min-height: 36rem;
    border-radius: var(--radius-md);
  }

  .core-claim {
    grid-template-columns: 1fr;
  }

  .scenario-shell {
    border-radius: var(--radius-md);
  }

  .scenario-map-wrap {
    padding: 0.35rem;
  }

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

  .scenario-metrics > div {
    min-height: 5.6rem;
  }

  .scenario-console {
    grid-template-columns: repeat(3, minmax(17.5rem, 1fr));
  }

  .loop-explainer {
    grid-template-columns: 1fr 1fr;
    justify-content: stretch;
  }

  .loop-explainer div:last-child {
    grid-column: 1 / -1;
  }

  .playbook summary {
    grid-template-columns: 2.5rem minmax(0, 1fr) auto;
  }

  .playbook summary small {
    grid-column: 2;
  }

  .playbook summary::after {
    grid-column: 3;
    grid-row: 1 / span 2;
  }

  .playbook details > div {
    grid-template-columns: 2.5rem minmax(0, 1fr);
  }

  .playbook details > div p,
  .playbook details > div code {
    grid-column: 2;
  }

  .anti-pattern-grid {
    grid-template-columns: 1fr;
  }

  .anti-pattern-grid article,
  .anti-pattern-grid article:nth-child(even) {
    border-right: 0;
  }

  .case {
    grid-template-columns: 1fr;
    gap: 1.1rem;
    padding: 2.4rem 0;
  }

  .case > a {
    grid-column: auto;
    white-space: normal;
  }

  .boundary-notes {
    grid-template-columns: 1fr;
  }

  .boundary-notes article {
    min-height: auto;
  }

  .site-footer {
    grid-template-columns: 1fr;
  }

  .site-footer > a {
    grid-column: auto;
    justify-self: start;
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto;
    animation-duration: 0.01ms;
    animation-iteration-count: 1;
    transition-duration: 0.01ms;
  }

  .js [data-reveal] {
    opacity: 1;
    transform: none;
  }
}

@media (forced-colors: active) {
  :root {
    scrollbar-color: auto;
  }

  *::-webkit-scrollbar,
  *::-webkit-scrollbar-track,
  *::-webkit-scrollbar-thumb {
    background: initial;
  }

  .button,
  .graph-node,
  .plan-list button,
  .quiz-options button {
    forced-color-adjust: auto;
  }

  .reading-progress span,
  .status-dot,
  .brand-mark i {
    background: Highlight;
  }
}

@media print {
  .site-header,
  .reading-progress,
  .hero-actions,
  .lens-switcher,
  .scenario-console,
  .knowledge-check,
  .site-footer a {
    display: none;
  }

  body {
    color: black;
    background: white;
  }

  .section-shell {
    width: 100%;
    padding-block: 2rem;
    break-inside: avoid;
  }

  .graph-card,
  .scenario-shell,
  .quiz-card {
    box-shadow: none;
  }
}