:root {
  --ink: #263238;
  --muted: #59686e;
  --line: #d6dfe1;
  --wash: #f0f4f4;
  --blue: #526b98;
  --blue-soft: #e1e8f3;
  --orange: #ad5736;
  --orange-soft: #fae8dd;
  --green: #327762;
  --green-soft: #e3f0e9;
  --red: #af4c4c;
  --red-soft: #f8e2e1;
  --sans: "Avenir Next", Avenir, "Segoe UI", sans-serif;
  --serif: Charter, "Bitstream Charter", Georgia, serif;
  --mono: "SFMono-Regular", Consolas, monospace;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
  scroll-padding-top: 95px;
}
body {
  margin: 0;
  background: #fff;
  color: var(--ink);
  font: 17px/1.75 var(--serif);
  -webkit-font-smoothing: antialiased;
}
a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}
button,
input,
summary {
  font: inherit;
}
button,
a,
summary {
  touch-action: manipulation;
}
button {
  cursor: pointer;
}
button:disabled {
  cursor: default;
}
button {
  color: var(--ink);
}
[hidden] {
  display: none !important;
}
h1,
h2,
h3,
h4,
p,
figure {
  margin: 0;
}
h1,
h2,
h3,
h4 {
  font-family: var(--sans);
  line-height: 1.25;
}
h2 {
  font-size: clamp(32px, 4.2vw, 46px);
  font-weight: 500;
  letter-spacing: -0.04em;
}
h3 {
  font-size: 26px;
  font-weight: 500;
  letter-spacing: -0.025em;
}
h4 {
  font-size: 19px;
  font-weight: 550;
}
p + p {
  margin-top: 20px;
}
svg {
  display: block;
  width: 100%;
  height: auto;
}
::selection {
  background: #ead8c6;
}
:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 5px;
}
.reading-width {
  width: min(850px, calc(100% - 64px));
  margin-inline: auto;
}
.skip {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 100;
  padding: 10px 18px;
  background: var(--ink);
  color: white;
  transform: translateY(-180%);
}
.skip:focus {
  transform: none;
}
.topbar {
  font-family: var(--sans);
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding: 18px max(32px, calc((100% - 1060px) / 2));
  background: #06151df2;
  color: #c4e9e5;
  backdrop-filter: blur(12px);
  border-bottom: 1px solid #8cdbd51a;
  min-height: 72px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 550;
  text-decoration: none;
  letter-spacing: -0.055em;
}
.brand svg {
  width: 29px;
  fill: none;
  stroke: #85e4d6;
  stroke-width: 2.3;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.topbar nav {
  display: flex;
  gap: 30px;
  font-size: 13px;
}
.topbar nav a {
  text-decoration: none;
  color: #b4c9d0;
}
.topbar nav a:hover,
.topbar nav a[aria-current] {
  color: #91f0df;
}
.mobile-menu {
  display: none;
}
.paper-toc {
  --toc-surface: #ffffffed;
  --toc-ink: #344a52;
  --toc-muted: #61777e;
  --toc-line: #dce5e7;
  --toc-active: #e4f1eb;
  --toc-accent: #286652;
  position: fixed;
  z-index: 12;
  top: 50%;
  right: max(24px, calc((100vw - 1760px) / 2 + 16px));
  transform: translateY(-50%);
  width: 208px;
  padding: 12px;
  border: 1px solid var(--toc-line);
  border-radius: 14px;
  background: var(--toc-surface);
  color: var(--toc-ink);
  box-shadow: 0 8px 30px #183c4810;
  backdrop-filter: blur(18px);
  font: 13px/1.4 var(--sans);
  transition: background-color .35s ease, border-color .35s ease, color .35s ease;
}
.paper-toc.is-over-hero {
  --toc-surface: #0b242ded;
  --toc-ink: #d0e7e9;
  --toc-muted: #9bbdc4;
  --toc-line: #80cfc130;
  --toc-active: #83e3ce1a;
  --toc-accent: #9aefda;
}
.paper-toc summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  padding: 4px 8px;
}
.toc-kicker { display: block; color: var(--toc-muted); font-size: 11px; letter-spacing: .08em; margin-bottom: 3px; }
.toc-title { font-size: 15px; font-weight: 600; }
.paper-toc summary::-webkit-details-marker { display: none; }
.paper-toc summary::after {
  content: "";
  width: 6px;
  height: 6px;
  border-right: 1.5px solid var(--toc-muted);
  border-bottom: 1.5px solid var(--toc-muted);
  transform: rotate(45deg);
  margin-right: 3px;
}
.paper-toc[open] summary::after { transform: rotate(225deg); }
.paper-toc nav {
  display: grid;
  gap: 8px;
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--toc-line);
  max-height: calc(100dvh - 220px);
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: var(--toc-line) transparent;
}
.paper-toc a {
  display: block;
  padding: 6px 8px;
  border-left: 2px solid transparent;
  border-radius: 0 5px 5px 0;
  text-decoration: none;
  color: var(--toc-muted);
  transition: color .25s ease, background-color .25s ease, border-color .25s ease;
}
.paper-toc .toc-section { font-weight: 600; color: var(--toc-ink); }
.toc-number { font: 11px var(--mono); color: var(--toc-muted); margin-right: 6px; }
.toc-studies { margin-left: 14px; border-left: 1px solid var(--toc-line); }
.paper-toc .toc-studies a { margin-left: -1px; padding-block: 5px; }
.toc-resources { border-top: 1px solid var(--toc-line); padding-top: 8px; }
.paper-toc a:hover { color: var(--toc-accent); background: var(--toc-active); }
.paper-toc a[aria-current] { color: var(--toc-accent); border-color: var(--toc-accent); background: var(--toc-active); font-weight: 600; }
.paper-toc a:focus-visible, .paper-toc summary:focus-visible { outline: 2px solid var(--toc-accent); outline-offset: -2px; }
@media (max-width: 1799px), (max-height: 740px) {
  .paper-toc {
    top: auto;
    right: max(16px, env(safe-area-inset-right));
    bottom: max(16px, env(safe-area-inset-bottom));
    transform: none;
    width: 174px;
    box-shadow: 0 8px 30px #183c4820;
  }
  .paper-toc[open] { width: min(264px, calc(100vw - 32px)); }
  .paper-toc nav { max-height: min(65dvh, calc(100dvh - 200px)); }
  .paper-toc:not([open]) .toc-kicker { display: none; }
  .paper-toc nav a { padding-block: 8px; }
}
@media print {
  .paper-toc { display: none; }
}
.masthead {
  background:
    radial-gradient(ellipse at 75% 35%, #15403966, transparent 55%),
    radial-gradient(ellipse at 12% 20%, #10334b55, transparent 55%),
    #06151d;
  color: #e1f3f2;
  padding-top: 88px;
  overflow: hidden;
}
.masthead::after {
  content: "";
  display: block;
  height: 160px;
  background: linear-gradient(180deg, #06151d00 0%, #18353d 22%, #607d83 48%, #c3d4d6 73%, #edf3f3 88%, #fff 100%);
}
.masthead .byline a {
  color: #c5dadc;
}
.masthead .byline span {
  color: inherit;
}
.masthead .byline img[src$="netsyn.svg"] {
  filter: brightness(0) invert(1);
  opacity: .85;
}
.masthead .deck {
  color: #b3d3d3;
}
.masthead .pill {
  color: #d7eeed;
  border-color: #89c5c54d;
  background: #16313c55;
}
.masthead .pill:hover {
  background: #234650;
  border-color: #8de6d7;
}
.masthead .pill.solid {
  color: #062b2e;
  background: #95eddd;
  border-color: #95eddd;
  box-shadow: 0 0 26px #70e5d019;
}
.masthead .pill.solid:hover {
  background: #b5f7eb;
}
.masthead .chapter-links {
  color: #b8d2d5;
  border-color: #83c0c328;
}
.masthead .chapter-links span {
  color: #84dfcf;
}
.masthead .chapter-links a:hover {
  color: #a2f1e2;
}
.byline {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  font: 14px var(--sans);
  color: var(--muted);
  margin-bottom: 30px;
}
.byline a {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--ink);
}
.byline img {
  display: block;
  width: auto;
  height: 60px;
  flex-shrink: 0;
}
.byline span {
  color: #94a1a7;
}
h1 {
  max-width: 830px;
  font-size: clamp(43px, 6.2vw, 72px);
  font-weight: 500;
  letter-spacing: -0.055em;
  line-height: 1.1;
}
h1 em {
  font-family: var(--serif);
  font-weight: 400;
  letter-spacing: -0.045em;
  color: var(--orange);
}
.deck {
  font: clamp(20px, 2.5vw, 26px)/1.5 var(--serif);
  margin-top: 30px;
}

.hero-links {
  display: flex;
  gap: 14px;
  margin-top: 30px;
}
.pill {
  display: inline-flex;
  align-items: center;
  gap: 28px;
  border: 1px solid #becbd0;
  border-radius: 5px;
  padding: 10px 18px;
  text-decoration: none;
  font: 13px/1.6 var(--sans);
  transition: background 0.2s;
}
.pill:hover {
  background: #dce4e8;
}
.pill.solid {
  background: var(--ink);
  border-color: var(--ink);
  color: white;
}
.pill.solid:hover {
  background: #445a64;
}
.hero-layout {
  width: calc(100% - 80px);
  max-width: 1160px;
  margin: 0 auto 64px;
  display: block;
}
.hero-copy h1 {
  font-size: clamp(44px, 4.7vw, 64px);
  color: #c2eee8;
  background: linear-gradient(120deg, #eef8fa 10%, #a2e8dc 90%);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-copy .deck {
  font-size: clamp(20px, 2vw, 24px);
}
@media (max-width: 600px) {
  .hero-layout { width: calc(100% - 40px); }
  .masthead::after { height: 100px; }
}
.chapter-links {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding-block: 23px 27px;
  font: 12px/1.5 var(--sans);
  border-top: 1px solid #cbd6da;
}
.chapter-links a {
  text-decoration: none;
}
.chapter-links span {
  margin-right: 8px;
  color: var(--orange);
}
.essay {
  padding-block: 100px;
}
.section-marker {
  font: 13px/1.5 var(--sans);
  color: var(--orange);
  margin-bottom: 15px;
}
.intro {
  font: 25px/1.5 var(--serif);
  margin: 25px 0;
  color: var(--ink);
}
.essay > p:not(.intro):not(.section-marker) {
  max-width: 760px;
}
.concept-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 55px;
  margin: 45px 0;
  border-block: 1px solid var(--line);
  padding-block: 34px;
}
.concept-symbol {
  display: block;
  font: 34px/1 var(--serif);
  margin-bottom: 20px;
}
.neural {
  color: var(--blue);
}
.symbolic {
  color: var(--orange);
}
.concept-pair h3 {
  font-size: 20px;
  font-weight: 550;
  line-height: 1.35;
  max-width: 290px;
}
.concept-pair p {
  font-size: 16px;
  color: var(--muted);
  margin-top: 14px;
}
.bridge {
  font-style: italic;
}
.chapter {
  padding-top: 55px;
  border-top: 1px solid var(--line);
}
.chapter-intro {
  padding-bottom: 18px;
}
.chapter-intro .intro {
  max-width: 730px;
}
.study {
  padding-top: 44px;
  padding-bottom: 72px;
}
.study + .study {
  padding-top: 50px;
}
.study-intro h3 {
  font-size: 29px;
  line-height: 1.35;
  font-weight: 400;
  max-width: 780px;
}
.study-intro h3 strong {
  font-weight: 600;
}
.study-intro > p {
  max-width: 750px;
  margin-top: 22px;
}
.paper-link {
  font: 13px/1.5 var(--sans);
  display: inline-block;
  margin-top: 20px;
  color: var(--blue);
  text-decoration: none;
}
.paper-link:hover {
  text-decoration: underline;
}
.interactive {
  max-width: 1060px;
  width: calc(100% - 64px);
  margin: 37px auto 0;
  background: var(--wash);
  border-radius: 8px;
  overflow: hidden;
}
.demo-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 15px;
  padding: 25px 32px 0;
  font: 15px/1.4 var(--sans);
}
.demo-top > p {
  font-weight: 550;
}
.player {
  display: flex;
  gap: 7px;
  flex-shrink: 0;
}
.player button {
  background: transparent;
  border: 1px solid #c4d0d4;
  border-radius: 4px;
  padding: 7px 12px;
  font: 12px/1.5 var(--sans);
  min-height: 34px;
}
.player button:hover {
  background: white;
}
.player button[data-reset] {
  font-size: 18px;
  padding: 3px 11px;
}
.visual {
  padding: 10px 40px 0;
  min-height: 200px;
}
.visual svg {
  overflow: visible;
}
.step-nav {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  padding-inline: 32px;
  margin-top: 8px;
  font-family: var(--sans);
}
.step-nav button {
  display: flex;
  gap: 10px;
  align-items: center;
  text-align: left;
  padding: 14px 7px;
  border: 0;
  border-top: 2px solid #c9d3d7;
  background: transparent;
  font: 13px/1.4 var(--sans);
  color: var(--muted);
}
.step-nav button span {
  font: 11px var(--mono);
  opacity: 0.65;
}
.step-nav button[aria-pressed="true"] {
  color: var(--blue);
  border-color: var(--blue);
  font-weight: 600;
}
.step-nav button:hover {
  background: #e7edef;
}
.narration {
  font: 16px/1.65 var(--serif);
  padding: 20px 39px 25px;
  min-height: 98px;
  max-width: 920px;
}
.interactive figcaption {
  font: 12px/1.65 var(--sans);
  color: var(--muted);
  padding: 18px 32px;
  border-top: 1px solid #dce4e6;
  background: #f7f9f9;
}
.diagram-text {
  font-family: var(--sans);
  fill: var(--ink);
}
.diagram-text.muted {
  fill: var(--muted);
}
.diagram-text.blue {
  fill: var(--blue);
}
.diagram-text.green {
  fill: var(--green);
}
.diagram-text.orange {
  fill: var(--orange);
}
.diagram-text.red {
  fill: var(--red);
}
.diagram-enter {
  animation: enter 0.3s ease both;
}
.diagram-draw {
  stroke-dasharray: 1600;
  stroke-dashoffset: 1600;
  animation: draw 0.65s ease forwards;
}
.diagram-pulse {
  animation: pulse 1.2s ease 2;
}
@keyframes enter {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@keyframes draw {
  to {
    stroke-dashoffset: 0;
  }
}
@keyframes pulse {
  50% {
    opacity: 0.4;
  }
}

.token-workbench {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 45px;
  padding-block: 35px;
  border-bottom: 1px solid var(--line);
}
.token-workbench h4 {
  font-size: 21px;
  line-height: 1.4;
}
.token-workbench p:not(.section-marker) {
  font-size: 15px;
  line-height: 1.65;
  margin-top: 13px;
  color: var(--muted);
}
.token-workbench .section-marker {
  font-size: 12px;
  margin-bottom: 8px;
}
.token-output {
  display: flex;
  align-items: center;
  gap: 17px;
  font: 13px var(--sans);
}
.token-output output {
  margin-left: auto;
  font: 28px var(--mono);
  min-width: 60px;
  min-height: 49px;
  text-align: center;
  border-bottom: 2px solid var(--blue);
  color: var(--blue);
}
.token-output button {
  border: 0;
  background: transparent;
  font-size: 23px;
}
#token-keys {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 4px;
  margin-top: 17px;
}
#token-keys button {
  border: 1px solid #a3b8c8;
  background: var(--blue-soft);
  color: var(--blue);
  font: 15px var(--mono);
  padding: 10px 0;
  border-radius: 3px;
  min-height: 41px;
}
#token-keys button:disabled {
  background: #f5f5f5;
  color: #939da3;
  border-color: #e1e5e7;
  text-decoration: line-through;
}
#token-keys button:hover:not(:disabled) {
  background: #cfdaea;
}
.token-finish {
  border: 0;
  background: transparent;
  color: var(--blue);
  padding: 12px 0 0;
  text-decoration: underline;
  text-underline-offset: 4px;
  font: 13px var(--sans);
}
.token-finish:disabled {
  color: #8a969b;
  text-decoration: none;
}
.experiment {
  margin-top: 38px;
  border-block: 1px solid var(--line);
  padding-block: 28px;
}
.experiment h4 {
  font-size: 20px;
  line-height: 1.4;
}
.experiment > p {
  font-size: 16px;
  margin-top: 15px;
  color: var(--muted);
}
.options {
  display: flex;
  flex-wrap: wrap;
  gap: 5px 22px;
  margin-top: 23px;
  font-family: var(--sans);
}
.options button {
  border: 0;
  border-bottom: 2px solid transparent;
  background: transparent;
  padding: 8px 0;
  font: 13px/1.5 var(--sans);
  color: var(--muted);
}
.options button[aria-pressed="true"] {
  border-color: var(--orange);
  color: var(--orange);
}
.packet-comparison {
  padding-block: 25px 8px;
}

.checks {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 15px;
  font: 12px var(--sans);
}
.checks .pass {
  color: var(--green);
}
.checks .fail {
  color: var(--red);
}
.clause-options {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 22px;
}
.clause-options button {
  border: 1px solid #cbd4d9;
  padding: 9px 12px;
  background: white;
  font: 13px var(--sans);
  border-radius: 4px;
}
.clause-options b {
  display: inline-block;
  margin-right: 8px;
  color: var(--blue);
}
.clause-options button[aria-pressed="true"] {
  background: var(--blue-soft);
  border-color: #9caecb;
}
.rule-evidence {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 15px;
  padding-top: 23px;
}
.observation {
  text-align: center;
  border-bottom: 3px solid var(--line);
  padding: 9px 4px;
  font: 14px/1.5 var(--sans);
  color: var(--muted);
}
.observation.covered {
  border-color: var(--green);
  color: var(--green);
}
.observation small {
  display: block;
  font-size: 11px;
  margin-top: 5px;
}
.experiment-heading {
  display: flex;
  justify-content: space-between;
  align-items: start;
  gap: 25px;
}
.experiment-heading h4 {
  max-width: 470px;
}
.guard-switch {
  display: flex;
  align-items: center;
  gap: 7px;
  font: 12px/1.5 var(--sans);
  flex-shrink: 0;
  padding-top: 4px;
  cursor: pointer;
}
.guard-switch input {
  width: 18px;
  height: 18px;
  accent-color: var(--blue);
}
.guard-visual {
  margin-top: 20px;
}
.small-note {
  font: 12px/1.65 var(--sans) !important;
}
.agenda-lines {
  margin-top: 45px;
}
.agenda-lines > div {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 30px;
  padding-block: 23px;
  border-top: 1px solid var(--line);
}
.agenda-lines h3 {
  font-size: 19px;
  font-weight: 500;
}
.agenda-lines p {
  font-size: 16px;
  color: var(--muted);
  margin: 0;
}
.papers {
  padding-block: 65px 80px;
  border-top: 1px solid var(--line);
}
.papers > p:not(.section-marker) {
  margin-top: 22px;
}
.paper-list {
  list-style: none;
  padding: 0;
  margin: 35px 0;
}
.paper-list li {
  padding: 25px 0;
  border-top: 1px solid var(--line);
}
.paper-meta {
  font: 12px/1.5 var(--sans);
  color: var(--blue);
  margin-bottom: 9px;
}
.paper-list h3 {
  font: 21px/1.4 var(--serif);
  letter-spacing: 0;
  max-width: 740px;
}
.paper-list h3 a {
  text-decoration: none;
}
.paper-list h3 a:hover {
  text-decoration: underline;
}
.paper-list p {
  font: 13px/1.65 var(--sans);
  margin-top: 8px;
  color: var(--muted);
}
.resource {
  display: inline-block;
  margin-top: 8px;
  font: 12px var(--sans);
  color: var(--blue);
  text-decoration: none;
}
.resource + .resource {
  margin-left: 20px;
}
footer {
  display: flex;
  justify-content: space-between;
  gap: 30px;
  border-top: 1px solid var(--line);
  padding-block: 30px 45px;
  font: 12px/1.7 var(--sans);
  color: var(--muted);
}
footer > a {
  white-space: nowrap;
  align-self: center;
}
@media (min-width: 1600px) {
  .masthead {
    padding-top: 110px;
  }
  .hero-art {
    margin-top: 30px;
  }
}
@media (max-width: 800px) {
  .topbar nav {
    gap: 20px;
  }
  .masthead {
    padding-top: 58px;
  }
  .concept-pair {
    gap: 30px;
  }
  .interactive {
    width: calc(100% - 36px);
  }
  .visual {
    padding: 10px 15px 0;
  }

  .token-workbench {
    gap: 25px;
  }
  .experiment-heading {
    display: block;
  }
  .guard-switch {
    margin-top: 15px;
  }
  .chapter-links {
    font-size: 11px;
    gap: 15px;
  }
  .demo-top {
    padding-inline: 24px;
  }
  .narration {
    padding-inline: 24px;
  }
  .step-nav {
    padding-inline: 24px;
  }
  .interactive figcaption {
    padding-inline: 24px;
  }
}
@media (max-width: 600px) {
  html {
    scroll-padding-top: 80px;
  }
  .reading-width {
    width: calc(100% - 40px);
  }
  body {
    font-size: 17px;
  }
  .topbar {
    padding: 15px 20px;
    min-height: 64px;
  }
  .topbar > nav {
    display: none;
  }
  .brand {
    font-size: 19px;
  }
  .mobile-menu {
    display: block;
    font: 13px var(--sans);
  }
  .mobile-menu summary {
    cursor: pointer;
  }
  .mobile-menu nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    padding: 20px;
    background: #0b202a;
    box-shadow: 0 8px 15px #24374715;
    display: flex;
    flex-direction: column;
    gap: 20px;
  }
  .masthead {
    padding-top: 43px;
  }
  .byline {
    font-size: 12px;
    margin-bottom: 25px;
  }
  h1 {
    font-size: 44px;
    letter-spacing: -0.055em;
  }
  .deck {
    font-size: 22px;
    line-height: 1.5;
    margin-top: 25px;
  }

  .hero-links {
    gap: 10px;
  }
  .pill {
    padding: 10px 14px;
    gap: 12px;
    font-size: 12px;
  }
  .hero-art {
    width: 145%;
    margin-left: -20%;
    margin-top: 30px;
  }
  .chapter-links {
    display: flex;
    flex-direction: column;
    gap: 14px;
    padding-block: 20px;
    font-size: 12px;
  }
  .essay {
    padding-block: 65px;
  }
  h2 {
    font-size: 34px;
  }
  .intro {
    font-size: 23px;
    margin-block: 22px;
  }
  .concept-pair {
    grid-template-columns: 1fr;
    gap: 28px;
    padding-block: 25px;
    margin-block: 30px;
  }
  .concept-pair > div {
    display: grid;
    grid-template-columns: 40px 1fr;
    gap: 0 15px;
  }
  .concept-symbol {
    grid-row: span 2;
    margin-top: 2px;
    font-size: 28px;
  }
  .concept-pair h3 {
    font-size: 18px;
    max-width: none;
  }
  .concept-pair p {
    grid-column: 2;
    font-size: 16px;
    margin-top: 10px;
  }
  .chapter {
    padding-top: 38px;
  }
  .study {
    padding-block: 30px 45px;
  }
  .study + .study {
    padding-top: 30px;
  }
  .study-intro h3 {
    font-size: 25px;
  }
  .study-intro > p {
    margin-top: 20px;
  }
  .interactive {
    width: calc(100% - 24px);
    margin-top: 26px;
    border-radius: 5px;
  }
  .demo-top {
    padding: 18px 16px 0;
    align-items: flex-start;
  }
  .demo-top > p {
    font-size: 13px;
    max-width: 220px;
  }
  .player {
    gap: 5px;
  }
  .player button {
    font-size: 11px;
    padding: 6px 8px;
    min-height: 32px;
  }
  .player button[data-reset] {
    font-size: 18px;
    padding: 1px 8px;
  }
  .visual {
    padding: 4px 8px 0;
  }
  .step-nav {
    padding-inline: 16px;
    grid-template-columns: 1fr 1fr;
    gap: 0 12px;
  }
  .step-nav button {
    font-size: 12px;
    padding-block: 11px;
    gap: 8px;
  }
  .narration {
    padding: 16px 17px 20px;
    font-size: 16px;
    min-height: 132px;
  }
  .interactive figcaption {
    padding: 15px 17px;
    font-size: 11px;
  }
  .token-workbench {
    grid-template-columns: 1fr;
    gap: 20px;
    padding-block: 25px;
  }
  .token-workbench h4 {
    font-size: 20px;
  }
  .token-workbench p:not(.section-marker) {
    font-size: 16px;
  }
  #token-keys button {
    min-height: 42px;
  }
  .token-output output {
    font-size: 26px;
  }

  .experiment {
    padding-block: 24px;
    margin-top: 26px;
  }
  .experiment h4 {
    font-size: 19px;
  }
  .options {
    gap: 0 16px;
    margin-top: 15px;
  }
  .options button {
    font-size: 12px;
  }

  .checks {
    gap: 10px;
    font-size: 11px;
  }
  .clause-options {
    flex-direction: column;
    gap: 8px;
  }
  .clause-options button {
    text-align: left;
    padding-block: 12px;
  }
  .rule-evidence {
    gap: 6px;
  }
  .observation {
    font-size: 12px;
  }
  .observation small {
    font-size: 10px;
  }
  .agenda-lines {
    margin-top: 30px;
  }
  .agenda-lines > div {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .agenda-lines p {
    font-size: 16px;
  }
  .papers {
    padding-block: 45px;
  }
  .paper-list h3 {
    font-size: 20px;
  }
  footer {
    flex-direction: column;
    gap: 18px;
  }
  footer > a {
    align-self: start;
  }
}
@media (max-width: 370px) {
  h1 {
    font-size: 38px;
  }
  .byline {
    font-size: 11px;
  }
  .hero-links {
    flex-wrap: wrap;
  }
  .demo-top {
    flex-wrap: wrap;
  }
  .rule-evidence {
    gap: 4px;
  }
  .observation {
    font-size: 11px;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
  .diagram-draw {
    stroke-dashoffset: 0 !important;
  }
}
@media print {
  .topbar,
  .player,
  .step-nav,
  .hero-links,
  .options,
  .clause-options,
  .guard-switch {
    display: none !important;
  }
  .masthead {
    padding-top: 20px;
    background: white;
    color: var(--ink);
  }
  .masthead::after {
    display: none;
  }
  .masthead .byline a,
  .masthead .deck,
  .masthead .chapter-links {
    color: var(--ink);
  }
  .masthead .byline img[src$="netsyn.svg"] {
    filter: none;
  }
  .hero-copy h1 {
    background: none;
    color: var(--ink);
    -webkit-text-fill-color: currentColor;
  }
  .essay,
  .study {
    padding-block: 30px;
  }
  .interactive {
    break-inside: avoid;
  }
  .visual {
    max-height: 350px;
  }
  .hero-art {
    display: none;
  }
  .chapter {
    break-before: page;
  }
  footer {
    padding-bottom: 0;
  }
}

.interactive.is-playing .data-flow {
  stroke-dasharray: 6 8;
  animation: flow 1s linear infinite;
}
@keyframes flow {
  to {
    stroke-dashoffset: -28;
  }
}

/* Direct manipulation and source-grounded diagrams */
.diagram-text.math {
  font-family: "STIX Two Math", "Cambria Math", Georgia, serif;
}
.diagram-tip {
  cursor: help;
}
.diagram-tip:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 4px;
}
.diagram-tooltip {
  position: fixed;
  z-index: 50;
  max-width: min(300px, calc(100vw - 24px));
  padding: 13px 16px;
  border-radius: 6px;
  box-shadow: 0 5px 22px #182d3826;
  background: #263238;
  color: white;
  font: 13px/1.65 var(--sans);
}
.flow-packet {
  animation: packet-travel var(--duration, 2.6s) linear infinite;
  animation-delay: var(--delay, 0s);
}
@keyframes packet-travel {
  0% {
    transform: translateX(0);
    opacity: 0;
  }
  2% {
    opacity: 1;
  }
  98% {
    opacity: 1;
  }
  100% {
    transform: translateX(var(--travel, 70px));
    opacity: 0;
  }
}
.packet-comparison {
  padding-top: 24px;
}
@media (max-width: 800px) {
  .topbar > nav {
    gap: 18px;
  }
  .brand {
    font-size: 17px;
  }
}
@media (max-width: 600px) {
  .byline {
    gap: 16px;
  }
  .byline a {
    flex-direction: column;
    gap: 12px;
  }
  .byline span {
    align-self: flex-end;
    line-height: 17px;
  }
  .brand {
    gap: 7px;
    font-size: 16px;
    line-height: 1.15;
    letter-spacing: -0.045em;
  }
  .brand svg {
    width: 23px;
    min-width: 23px;
  }
  .brand span {
    max-width: 170px;
  }
  .topbar {
    gap: 12px;
  }
  .mobile-menu {
    flex-shrink: 0;
    font-size: 12px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .flow-packet {
    animation: none;
    transform: translateX(var(--still, 0px));
  }
}

.bitrate-bar {
  transform-box: fill-box;
  transform-origin: center bottom;
  animation: bar-rise 0.75s ease-out both;
}
@keyframes bar-rise {
  from {
    transform: scaleY(0);
  }
  to {
    transform: scaleY(1);
  }
}
@media (prefers-reduced-motion: reduce) {
  .bitrate-bar {
    animation: none;
  }
}

@media (min-width: 601px) and (max-width: 960px) {
  .topbar {
    padding-inline: 22px;
  }
  .topbar > nav {
    gap: 14px;
    font-size: 12px;
  }
  .brand {
    font-size: 17px;
  }
}

.token-legend {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  padding: 14px 39px 0;
  font: 13px/1.5 var(--sans);
}
.token-legend span::before {
  content: "";
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-right: 8px;
  border: 1px solid currentColor;
  border-radius: 2px;
  background: currentColor;
  opacity: 0.75;
}
.candidate-key {
  color: var(--blue);
}
.masked-key {
  color: var(--red);
}
.allowed-key {
  color: var(--green);
}
.lejit-candidate {
  animation: token-propose 1.7s linear both;
}
.lejit-candidate.allowed > rect {
  animation: token-allow 1.7s linear both;
}
.lejit-candidate.masked > rect {
  animation: token-mask 1.7s linear both;
}
.lejit-candidate.masked > text {
  animation: token-dim 1.7s linear both;
}
.token-mask-cross {
  opacity: 0;
}
.masked .token-mask-cross {
  animation: token-cross 1.7s linear both;
}
.lejit-flying-token {
  animation: token-deliver 1.7s linear both;
}
.lejit-output-new {
  animation: token-append 1.7s linear both;
}
.lejit-filter {
  animation: mask-pulse 1.7s linear both;
}
.lejit-live.is-paused * {
  animation-play-state: paused !important;
}
@keyframes token-propose {
  0% {
    opacity: 0;
    transform: translateX(-25px);
  }
  16%,
  100% {
    opacity: 1;
    transform: translateX(0);
  }
}
@keyframes token-allow {
  0%,
  27% {
    fill: var(--blue-soft);
    stroke: var(--blue);
  }
  36%,
  100% {
    fill: var(--green-soft);
    stroke: var(--green);
  }
}
@keyframes token-mask {
  0%,
  27% {
    fill: var(--blue-soft);
    stroke: var(--blue);
  }
  36%,
  100% {
    fill: var(--red-soft);
    stroke: var(--red);
  }
}
@keyframes token-dim {
  0%,
  27% {
    opacity: 1;
  }
  36%,
  100% {
    opacity: 0.3;
  }
}
@keyframes token-cross {
  0%,
  27% {
    opacity: 0;
  }
  36%,
  100% {
    opacity: 1;
  }
}
@keyframes token-deliver {
  0%,
  40% {
    opacity: 0;
    transform: translate(var(--from-x), var(--from-y));
  }
  43% {
    opacity: 1;
    transform: translate(var(--from-x), var(--from-y));
  }
  56% {
    opacity: 1;
    transform: translate(var(--gate-x), 260px);
  }
  68%,
  73% {
    opacity: 1;
    transform: translate(var(--pick-x), 260px);
  }
  89% {
    opacity: 1;
    transform: translate(var(--out-x), 462px);
  }
  90%,
  100% {
    opacity: 0;
    transform: translate(var(--out-x), 462px);
  }
}
@keyframes token-append {
  0%,
  88% {
    opacity: 0;
  }
  90%,
  100% {
    opacity: 1;
  }
}
@keyframes mask-pulse {
  0%,
  25%,
  55%,
  100% {
    opacity: 0.65;
  }
  30%,
  45% {
    opacity: 1;
  }
}
.controller-shield {
  animation: shield-appear 0.3s ease-out both;
}
@keyframes shield-appear {
  from {
    opacity: 0.1;
  }
  to {
    opacity: 1;
  }
}
@media (max-width: 600px) {
  .token-legend {
    padding-inline: 20px;
    gap: 10px;
    font-size: 11px;
  }
}
@media (min-width: 601px) and (max-width: 1040px) {
  .topbar > nav {
    display: none;
  }
  .mobile-menu {
    display: block;
    font: 13px var(--sans);
  }
  .mobile-menu summary {
    cursor: pointer;
  }
  .mobile-menu nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    display: flex;
    flex-direction: column;
    gap: 20px;
    padding: 20px;
    background: white;
    box-shadow: 0 8px 15px #24374715;
  }
}
@media (prefers-reduced-motion: reduce) {
  .lejit-scene *,
  .controller-shield {
    animation: none !important;
  }
  .lejit-candidate.allowed > rect {
    fill: var(--green-soft);
    stroke: var(--green);
  }
  .lejit-candidate.masked > rect {
    fill: var(--red-soft);
    stroke: var(--red);
  }
  .lejit-candidate.masked > text {
    opacity: 0.3;
  }
  .masked .token-mask-cross {
    opacity: 1;
  }
  .lejit-flying-token {
    display: none;
  }
}

.lejit-selection {
  animation: token-selection 1.7s linear both;
}
@keyframes token-selection {
  0%,
  66% {
    opacity: 0;
  }
  72%,
  100% {
    opacity: 1;
  }
}
@media (prefers-reduced-motion: reduce) {
  .lejit-selection {
    animation: none;
  }
}

.external-link-icon {
  display: inline-block;
  width: .9em;
  height: .9em;
  flex-shrink: 0;
  vertical-align: -.08em;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}


/* Evidence moves through the new research diagrams. */
.research-traveler {
  offset-distance: 35%;
  animation: evidence-travel 2.8s linear infinite;
  animation-delay: var(--travel-delay, 0s);
}
.research-flow {
  animation: flow 1.8s linear infinite;
}
.research-scan {
  animation: grammar-scan 3s ease-in-out infinite alternate;
}
.student-command { animation: student-command-align .65s ease-out both; }
@keyframes student-command-align {
  from { transform: translateY(var(--row-shift, 0px)); opacity: .5; }
  to { transform: translateY(0); opacity: 1; }
}
@media (prefers-reduced-motion: reduce) {
  .student-command { animation: none; }
}
[data-demo]:not(.is-playing) .flow-packet,
.research-demo:not(.is-playing) .research-traveler,
.research-demo:not(.is-playing) .research-flow,
.research-demo:not(.is-playing) .research-scan {
  animation-play-state: paused;
}
@keyframes evidence-travel {
  from { offset-distance: 0%; }
  to { offset-distance: 100%; }
}
@keyframes grammar-scan {
  to { transform: translateX(var(--scan-width)); }
}
@media (prefers-reduced-motion: reduce) {
  .research-traveler { offset-distance: 45%; }
}

/* Three reference scenes: benefits, failures, and domain knowledge. */
.examples-section { max-width: 1280px; width: calc(100% - 80px); }
.examples-section > p, .examples-section > h2 { max-width: 800px; margin-inline: auto; }
.background-story { margin-block: 36px; padding: 28px; border-radius: 14px; background: #f0f4f4; color: var(--ink); border: 1px solid var(--line); }
.bg-controls { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.bg-stages { display: flex; gap: 8px; flex-wrap: wrap; }
.bg-controls button, .bg-cases button { font: 14px/1.4 var(--sans); padding: 11px 14px; border: 1px solid #bac9cf; border-radius: 7px; color: var(--muted); background: transparent; }
.bg-stages button span { color: var(--muted); margin-right: 5px; }
.bg-controls button[aria-pressed="true"], .bg-cases button[aria-pressed="true"] { background: #327762; color: #ffffff; border-color: #327762; }
.bg-stages button[aria-pressed="true"] span { color: #ffffff; }
.bg-controls button:hover, .bg-cases button:hover { border-color: #327762; }
.background-story button:focus-visible { outline: 3px solid #327762; outline-offset: 3px; }
.bg-play { flex-shrink: 0; min-width: 94px; }
.bg-narration { font: 500 clamp(23px, 2.4vw, 32px)/1.4 var(--sans); color: #327762; min-height: 90px; margin-block: 30px 24px; }
.bg-panels { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.bg-panel { border: 1px solid var(--line); background: #ffffff; border-radius: 12px; overflow: hidden; min-width: 0; }
.bg-panel h3 { display: flex; align-items: center; font: 650 clamp(19px, 1.9vw, 25px)/1.25 var(--sans); background: #dcece8; color: #285c58; letter-spacing: 0; padding: 18px 20px; min-height: 94px; }
.bg-panel-body { padding: 22px 20px 25px; }
.bg-panel .bg-note { font: 500 18px/1.45 var(--sans); min-height: 136px; margin: 0; transition: color .5s ease; }
.bg-panel svg { margin-block: 0 30px; overflow: visible; }
.bg-panel svg text { font: 15px var(--sans); fill: var(--muted); }
.bg-panel .bg-outcome { font: 17px/1.5 var(--sans); min-height: 156px; padding-top: 20px; margin: 0; color: var(--ink); white-space: pre-line; transition: color .5s ease; }
.bg-bar { transition: y .55s ease, height .55s ease, fill .4s ease; }
.bg-rate-good, .bg-rate-bad, .bg-bbr { fill: none; stroke: #327762; stroke-width: 3; transition: opacity .55s ease; }
.bg-rate-bad { stroke: #b65343; opacity: 0; }
.bg-bbr { stroke: #81939d; stroke-dasharray: 5 4; stroke-width: 2.5; opacity: 0; }
.bg-gap, .bg-legend, .bg-perturb, .bg-impossible-label, .bg-web-label { opacity: 0; transition: opacity .45s ease; }
.bg-track-label, .bg-coarse-label, .bg-video-label { transition: opacity .45s ease; }
.bg-panel svg .bg-impossible-label { fill: #b65343; }
.bg-panel svg .bg-video-label text, .bg-panel svg .bg-web-label text { fill: var(--ink); font-weight: 700; font-size: 18px; }
.bg-packet { transition: transform .55s ease, fill .4s ease; }
.background-story:not([data-bg-stage="0"]) .bg-rate-good,
.background-story:not([data-bg-stage="0"]) .bg-coarse-label,
.background-story:not([data-bg-stage="0"]) .bg-track-label,
.background-story:not([data-bg-stage="0"]) .bg-video-label { opacity: 0; }
.background-story:not([data-bg-stage="0"]) .bg-rate-bad,
.background-story:not([data-bg-stage="0"]) .bg-bbr,
.background-story:not([data-bg-stage="0"]) .bg-gap,
.background-story:not([data-bg-stage="0"]) .bg-legend,
.background-story:not([data-bg-stage="0"]) .bg-perturb,
.background-story:not([data-bg-stage="0"]) .bg-impossible-label,
.background-story:not([data-bg-stage="0"]) .bg-web-label { opacity: 1; }
.background-story:not([data-bg-stage="0"]) .bg-packet-shift { transform: translateX(13px); fill: #b65343; }
.background-story:not([data-bg-stage="0"]) .bg-note { color: #b65343; }
[data-bg-stage="1"] .bg-outcome { color: var(--muted); }
[data-bg-stage="2"] .bg-outcome { color: #327762; font-size: 19px; }
.bg-enforced, .bg-rate-protected { opacity: 0; transition: opacity .55s ease; }
.bg-rate-protected { fill: none; stroke: #327762; stroke-width: 3; }
.bg-panel svg .bg-enforced text { fill: #327762; }
.background-story[data-bg-stage="2"] .bg-note { color: #327762; }
.background-story[data-bg-stage="2"] .bg-enforced,
.background-story[data-bg-stage="2"] .bg-rate-protected,
.background-story[data-bg-stage="2"] .bg-video-label { opacity: 1; }
.background-story[data-bg-stage="2"] .bg-web-label,
.background-story[data-bg-stage="2"] .bg-impossible-label,
.background-story[data-bg-stage="2"] .bg-legend,
.background-story[data-bg-stage="2"] .bg-gap,
.background-story[data-bg-stage="2"] .bg-bbr { opacity: 0; }
.background-story[data-bg-stage="2"] .bg-rate-bad { opacity: .35; stroke-dasharray: 4 4; }
.background-story[data-bg-stage="2"] .bg-packet-shift { fill: #327762; }
.background-story[data-bg-stage="2"] .bg-perturb { stroke: #327762; }
.bg-panel svg .bg-video-label rect { fill: #e3f0e9; }
.bg-panel svg .bg-web-label rect { fill: #fae8e3; }
.bg-panel svg .bg-video-label text { fill: #285c48; }
.bg-panel svg .bg-web-label text { fill: #a04737; }
.bg-cases { display: none; }
@media (max-width: 900px) {
  .examples-section { width: calc(100% - 40px); }
  .background-story { padding: 18px; }
  .bg-controls { align-items: stretch; }
  .bg-stages { flex-direction: column; flex: 1; }
  .bg-stages button { text-align: left; }
  .bg-play { align-self: center; }
  .bg-cases { display: flex; gap: 8px; margin-bottom: 16px; flex-wrap: wrap; }
  .bg-cases button { flex: 1; padding: 9px; font-size: 13px; }
  .bg-panels { grid-template-columns: 1fr; }
  .is-enhanced .bg-panel { display: none; }
  [data-bg-case="0"].is-enhanced [data-bg-panel="0"],
  [data-bg-case="1"].is-enhanced [data-bg-panel="1"],
  [data-bg-case="2"].is-enhanced [data-bg-panel="2"] { display: block; }
  .bg-panel h3 { min-height: 0; font-size: 23px; }
  .bg-panel .bg-note { min-height: 106px; }
  .bg-panel svg { max-width: 480px; margin-inline: auto; }
  .bg-panel .bg-outcome { min-height: 132px; }
  .bg-narration { min-height: 130px; font-size: 23px; }
}
@media (prefers-reduced-motion: reduce) {
  .background-story * { transition: none !important; }
}
@media print {
  .bg-controls, .bg-cases { display: none !important; }
  .background-story .bg-panel { display: block !important; break-inside: avoid; }
}

/* Community invitations use the same light surfaces as the research demos. */
.contribute { max-width: 1120px; padding-block: 70px 90px; border-top: 1px solid var(--line); }
.contribute > .intro { max-width: 800px; }
.contribute-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; margin-top: 32px; }
.contribute-grid article { display: flex; flex-direction: column; align-items: flex-start; padding: 26px; background: var(--wash); border: 1px solid var(--line); border-radius: 10px; }
.contribute-grid h3 { font-size: 23px; }
.contribute-grid p { margin-block: 18px 24px; font-size: 17px; }
.contribute-grid .pill { margin-top: auto; background: white; font-size: 14px; }
.contribute-grid .pill:hover { background: var(--green-soft); }
.contribute .contribute-note { margin-top: 22px; color: var(--muted); font: 14px/1.6 var(--sans); }
main > .community-papers:first-child { border-top: 0; }
.community-papers > p { max-width: 800px; }
.community-papers h1 { font-size: clamp(32px, 4.2vw, 46px); font-weight: 500; letter-spacing: -0.04em; }
.paper-list-title { margin-top: 48px; font-size: 18px; font-weight: 600; letter-spacing: -.01em; }
.paper-list-title + .paper-list { margin-top: 16px; }
.reading-list-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 24px; margin-top: 32px; }
.reading-list-actions .resource { margin-top: 0; }
.people { max-width: 1120px; padding-block: 70px 90px; border-top: 1px solid var(--line); }
.people-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 32px 20px; margin: 32px 0 0; padding: 0; list-style: none; text-align: center; }
.people-grid img { display: block; width: 100%; max-width: 160px; height: auto; aspect-ratio: 1; margin: 0 auto 16px; object-fit: cover; border-radius: 50%; border: 1px solid var(--line); }
.people-grid h3 { font-size: 19px; }
.people-grid h3 a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 4px; }
@media (min-width: 601px) and (max-width: 1100px) {
  .topbar { flex-wrap: wrap; gap: 12px; }
  .topbar > nav { flex-basis: 100%; justify-content: space-between; gap: 12px; font-size: 13px; flex-wrap: wrap; }
}
@media (max-width: 800px) {
  .contribute-grid { grid-template-columns: 1fr; }
  .contribute { padding-block: 48px 64px; }
  .people { padding-block: 48px 64px; }
  .people-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}


/* The same knowledge cycle connects all three application areas. */
.hero-copy { max-width: 960px; }
.hero-copy .deck { max-width: 880px; }
.hero-layout .byline { margin-bottom: 42px; }
.princeton-affiliation { text-align: right; }
.knowledge-path {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  list-style: none;
  padding: 0;
  margin: 36px 0 0;
  gap: 32px;
  font-family: var(--sans);
}
.knowledge-path li { position: relative; padding-top: 18px; border-top: 1px solid #83c0c344; }
.knowledge-path li:not(:last-child)::after { content: "→"; position: absolute; right: -24px; top: 32px; color: #83c0c3; }
.knowledge-path strong { display: block; font-size: 24px; font-weight: 550; color: #95eddd; }
.knowledge-path span:last-child { font-size: 13px; color: #b3d3d3; }
.knowledge-path .path-number { float: right; color: #779a9f; font-size: 12px; }
.knowledge-cycle { margin: 70px 0 38px; scroll-margin-top: 24px; }
.knowledge-cycle > h3 { font-size: clamp(28px, 3vw, 38px); }
.knowledge-intro { max-width: 750px; margin-top: 16px; }
.knowledge-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px; margin-top: 28px; }
.knowledge-card { border: 1px solid var(--line); border-radius: 10px; overflow: hidden; display: grid; grid-template-rows: auto 1fr auto; background: #fff; }
.knowledge-card header { min-height: 108px; padding: 20px; background: #dcece8; }
.knowledge-card h4 { font-size: 21px; line-height: 1.3; color: #285c58; }
.knowledge-card header p { font: 14px/1.5 var(--sans); margin-top: 8px; color: var(--muted); }
.knowledge-card ol { display: grid; grid-template-rows: repeat(3, 1fr); padding: 0; margin: 0; list-style: none; }
.knowledge-card li { padding: 20px; border-bottom: 1px solid var(--line); }
.knowledge-card h5 { margin: 0 0 10px; font: 550 18px/1.4 var(--sans); color: var(--blue); }
.knowledge-card h5 span { margin-right: 8px; font-size: 12px; opacity: .75; }
.knowledge-card li:nth-child(2) h5 { color: var(--orange); }
.knowledge-card li:nth-child(3) h5 { color: var(--green); }
.knowledge-card li p { font: 16px/1.55 var(--serif); }
.knowledge-card footer { display: flex; flex-wrap: wrap; justify-content: flex-start; gap: 10px 18px; padding: 16px 20px; margin: 0; border: 0; background: var(--wash); font: 13px/1.5 var(--sans); }
.knowledge-card footer a { color: var(--blue); }
@media (max-width: 900px) {
  .knowledge-grid { grid-template-columns: 1fr; }
  .knowledge-card header { min-height: 0; }
  .knowledge-card ol { grid-template-rows: auto; }
}
@media (max-width: 600px) {
  .hero-layout .byline { align-items: flex-start; }
  .byline .princeton-affiliation { flex-direction: column-reverse; }
  .knowledge-path { gap: 18px; }
  .knowledge-path strong { font-size: 19px; }
  .knowledge-path span:last-child { display: block; font-size: 12px; margin-top: 5px; }
  .knowledge-path .path-number { float: none; display: block; margin-bottom: 6px; }
  .knowledge-path li:not(:last-child)::after { right: -14px; top: 37px; }
  .knowledge-card footer { flex-direction: row; }
}
@media print {
  .knowledge-path strong, .knowledge-path span:last-child { color: var(--ink); }
  .knowledge-card { break-inside: avoid; }
}


/* Formal reasoning and statistical learning share the hero backdrop. */
.masthead { position: relative; isolation: isolate; }
.hero-backdrop { position: absolute; inset: 80px 0 120px; z-index: 0; pointer-events: none; }
.hero-backdrop img { display: block; width: 100%; height: 100%; object-fit: cover; object-position: center; }
.masthead::before { content: ""; position: absolute; inset: 0; z-index: 1; background: linear-gradient(90deg, #06151deb 0%, #06151dcc 35%, #06151d66 70%, #06151d26 100%), linear-gradient(180deg, #06151d 0%, transparent 24%, transparent 65%, #06151d 90%); pointer-events: none; }
.hero-layout, .masthead .chapter-links, .masthead::after { position: relative; z-index: 2; }
.methodology-label { font: 600 14px/1.5 var(--sans); color: #a5f4e4; }
.hero-copy .methodology-label { margin-top: 36px; }
.knowledge-path { gap: 24px; margin-top: 14px; }
.knowledge-path li { padding: 22px 20px; border: 1px solid #88e9d882; border-radius: 10px; background: #102f35ed; box-shadow: 0 6px 24px #0003, inset 0 3px #95eddd; }
.knowledge-path strong { font-size: 30px; color: #b5ffef; }
.knowledge-path span:last-child { display: block; margin-top: 5px; color: #d2eae7; }
.knowledge-path .path-number { color: #a5f4e4; }
.knowledge-path li:not(:last-child)::after { right: -20px; top: 42px; color: #a5f4e4; }
.examples-section { padding-top: 0; }
.examples-section .background-story { margin-top: 0; }
.knowledge-cycle { max-width: 1280px; width: calc(100% - 80px); margin: 64px auto; padding: 38px; border-radius: 16px; background: #0b2932; border: 1px solid #285459; box-shadow: 0 10px 35px #16313c17; }
.knowledge-cycle > h2 { margin-top: 10px; color: #a5f4e4; font-size: clamp(32px, 3.6vw, 46px); }
.knowledge-cycle > .knowledge-intro { color: #d2eae7; max-width: 860px; }
.knowledge-card { border-color: #547477; }
.knowledge-card h5 { font-size: 20px; font-weight: 650; }
.knowledge-card li:nth-child(1) { background: #f3f6fc; }
.knowledge-card li:nth-child(2) { background: #fff7f1; }
.knowledge-card li:nth-child(3) { background: #edf7f1; }
@media (max-width: 900px) {
  .knowledge-cycle { width: calc(100% - 40px); padding: 24px; }
  .hero-backdrop { inset: 120px 0 100px; opacity: .65; }
}
@media (max-width: 600px) {
  .hero-backdrop img { object-position: 66% center; }
  .masthead::before { background: linear-gradient(90deg, #06151dcc, #06151d88), linear-gradient(180deg, #06151d, transparent 35%, #06151d 92%); }
  .knowledge-path { gap: 10px; }
  .knowledge-path li { padding: 14px 9px; }
  .knowledge-path strong { font-size: 20px; }
  .knowledge-path span:last-child { font-size: 12px; }
  .knowledge-path li:not(:last-child)::after { content: none; }
  .knowledge-cycle { width: calc(100% - 24px); padding: 22px 16px; }
  .knowledge-card li, .knowledge-card header { padding: 18px; }
}
@media (max-width: 370px) {
  .knowledge-path strong { font-size: 18px; }
  .knowledge-path li { padding-inline: 7px; }
}
@media print {
  .hero-backdrop, .masthead::before { display: none; }
  .knowledge-cycle, .knowledge-path li { background: white; box-shadow: none; }
  .methodology-label, .knowledge-cycle > h2, .knowledge-cycle > .knowledge-intro, .knowledge-path strong, .knowledge-path span:last-child { color: var(--ink); }
}

.research-support {
  padding-block: 48px 56px;
  border-top: 1px solid var(--line);
  text-align: center;
}
.research-support h2 { font-size: 28px; letter-spacing: -.025em; }
.support-logos {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-items: center;
  gap: 32px;
  max-width: 520px;
  margin: 24px auto;
}
.support-logos a { display: flex; justify-content: center; align-items: center; min-height: 132px; padding: 8px; border-radius: 5px; }
.support-logos img { display: block; height: auto; max-width: 100%; object-fit: contain; }
.support-logos img[src$="nsf.png"] { width: 185px; }
.support-logos img[src$="onr.png"] { width: 200px; }
.research-support > p { max-width: 600px; margin-inline: auto; color: var(--muted); font-size: 16px; }
@media (max-width: 600px) {
  .research-support { padding-block: 36px 44px; }
  .support-logos { gap: 16px; margin-block: 20px; }
  .support-logos a { min-height: 100px; padding: 4px; }
}