:root{--c-surface:#fcfcfa;--c-ink:#1d1c1a;--c-ink2:#52514e;--c-ink3:#6b6a66;--c-line:#8a8882;--c-rule:#e4e3dc;--c-rule2:#cfcdc4;--c-tissue:#efede6;--c-tissue2:#e3e0d6;--c-tissue3:#d2cec2;--c-outline:#7c7a73;--c-halo:#fcfcfa;--c-accent:#b8461b;--c-accentMark:#eb6834;--c-blue:#2a78d6;--c-blue-tint:#dbe7f6;--c-blue-soft:#bad3f1;--c-blue-mid:#8cb5ea;--c-blue-deep:#164884;--c-orange:#eb6834;--c-orange-tint:#fde5db;--c-orange-soft:#fccfbd;--c-orange-mid:#f9ae92;--c-orange-deep:#913e1c;--c-aqua:#1baf7a;--c-aqua-tint:#def0e5;--c-aqua-soft:#c1e4d0;--c-aqua-mid:#94d2b2;--c-aqua-deep:#0c6b49;--c-yellow:#eda100;--c-yellow-tint:#fbeedc;--c-yellow-soft:#f9e0bd;--c-yellow-mid:#f6cb90;--c-yellow-deep:#936200;--c-magenta:#e87ba4;--c-magenta-tint:#fbe8ec;--c-magenta-soft:#f9d3de;--c-magenta-mid:#f5b6ca;--c-magenta-deep:#904a64;--c-green:#008300;--c-green-tint:#d9e9d6;--c-green-soft:#b7d6b2;--c-green-mid:#85ba7f;--c-green-deep:#004f00;--c-violet:#4a3aa7;--c-violet-tint:#dcddef;--c-violet-soft:#bdbee3;--c-violet-mid:#9292d0;--c-violet-deep:#2a2066;--c-red:#e34948;--c-red-tint:#fde1dd;--c-red-soft:#fbc6c0;--c-red-mid:#f69f97;--c-red-deep:#8c2a29;color-scheme:light}
:root[data-theme="dark"]{--c-surface:#171716;--c-ink:#ebe9e3;--c-ink2:#c3c2b7;--c-ink3:#a3a198;--c-line:#8f8d86;--c-rule:#2e2e2b;--c-rule2:#45443f;--c-tissue:#252523;--c-tissue2:#2f2e2b;--c-tissue3:#3c3b37;--c-outline:#8f8d86;--c-halo:#171716;--c-accent:#f08a5d;--c-accentMark:#ee7a4a;--c-blue:#3987e5;--c-blue-tint:#223042;--c-blue-soft:#284161;--c-blue-mid:#2f5a8f;--c-blue-deep:#74aaef;--c-orange:#d95926;--c-orange-tint:#41281e;--c-orange-soft:#5f3222;--c-orange-mid:#8a4126;--c-orange-deep:#e98b69;--c-aqua:#199e70;--c-aqua-tint:#20342a;--c-aqua-soft:#244938;--c-aqua-mid:#26674b;--c-aqua-deep:#6db996;--c-yellow:#c98500;--c-yellow-tint:#3d2f1d;--c-yellow-soft:#58401f;--c-yellow-mid:#7f591e;--c-yellow-deep:#d9a865;--c-magenta:#d55181;--c-magenta-tint:#40262d;--c-magenta-soft:#5d303d;--c-magenta-mid:#873c55;--c-magenta-deep:#e685a3;--c-green:#008300;--c-green-tint:#1d2f1a;--c-green-soft:#1e401b;--c-green-mid:#1d5719;--c-green-deep:#60a65b;--c-violet:#9085e9;--c-violet-tint:#302f42;--c-violet-soft:#434062;--c-violet-mid:#5e5991;--c-violet-deep:#ada8f1;--c-red:#e66767;--c-red-tint:#432a28;--c-red-soft:#633735;--c-red-mid:#914847;--c-red-deep:#f29490;color-scheme:dark}
@media (prefers-color-scheme:dark){:root:not([data-theme]){--c-surface:#171716;--c-ink:#ebe9e3;--c-ink2:#c3c2b7;--c-ink3:#a3a198;--c-line:#8f8d86;--c-rule:#2e2e2b;--c-rule2:#45443f;--c-tissue:#252523;--c-tissue2:#2f2e2b;--c-tissue3:#3c3b37;--c-outline:#8f8d86;--c-halo:#171716;--c-accent:#f08a5d;--c-accentMark:#ee7a4a;--c-blue:#3987e5;--c-blue-tint:#223042;--c-blue-soft:#284161;--c-blue-mid:#2f5a8f;--c-blue-deep:#74aaef;--c-orange:#d95926;--c-orange-tint:#41281e;--c-orange-soft:#5f3222;--c-orange-mid:#8a4126;--c-orange-deep:#e98b69;--c-aqua:#199e70;--c-aqua-tint:#20342a;--c-aqua-soft:#244938;--c-aqua-mid:#26674b;--c-aqua-deep:#6db996;--c-yellow:#c98500;--c-yellow-tint:#3d2f1d;--c-yellow-soft:#58401f;--c-yellow-mid:#7f591e;--c-yellow-deep:#d9a865;--c-magenta:#d55181;--c-magenta-tint:#40262d;--c-magenta-soft:#5d303d;--c-magenta-mid:#873c55;--c-magenta-deep:#e685a3;--c-green:#008300;--c-green-tint:#1d2f1a;--c-green-soft:#1e401b;--c-green-mid:#1d5719;--c-green-deep:#60a65b;--c-violet:#9085e9;--c-violet-tint:#302f42;--c-violet-soft:#434062;--c-violet-mid:#5e5991;--c-violet-deep:#ada8f1;--c-red:#e66767;--c-red-tint:#432a28;--c-red-soft:#633735;--c-red-mid:#914847;--c-red-deep:#f29490;color-scheme:dark}}
/* Neuroscience Book — website styles.
   Color tokens (--c-*) are generated from figures/lib/palette.mjs and prepended
   to this file at build time, for light and dark themes. */

/* ---------------------------------------------------------------- Fonts --- */

@font-face {
  font-family: 'Source Serif 4';
  src: url('/assets/fonts/source-serif-4.woff2') format('woff2');
  font-weight: 200 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Source Serif 4';
  src: url('/assets/fonts/source-serif-4-italic.woff2') format('woff2');
  font-weight: 200 900;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: 'Inter';
  src: url('/assets/fonts/inter.woff2') format('woff2');
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Inter';
  src: url('/assets/fonts/inter-italic.woff2') format('woff2');
  font-weight: 100 900;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: 'JetBrains Mono';
  src: url('/assets/fonts/jetbrains-mono.woff2') format('woff2');
  font-weight: 100 800;
  font-style: normal;
  font-display: swap;
}

/* --------------------------------------------------------------- Tokens --- */

:root {
  --font-serif: 'Source Serif 4', 'Source Serif Pro', Charter, Georgia, serif;
  --font-sans: 'Inter', ui-sans-serif, system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;

  --bg: var(--c-surface);
  --ink: var(--c-ink);
  --ink-2: var(--c-ink2);
  --ink-3: var(--c-ink3);
  --rule: var(--c-rule);
  --rule-2: var(--c-rule2);
  --accent: var(--c-accent);
  --accent-mark: var(--c-accentMark);
  --raised: color-mix(in oklab, var(--c-tissue) 55%, var(--c-surface));
  --wash-accent: color-mix(in oklab, var(--c-accentMark) 7%, var(--c-surface));
  --wash-blue: color-mix(in oklab, var(--c-blue) 7%, var(--c-surface));
  --code-bg: color-mix(in oklab, var(--c-tissue) 75%, var(--c-surface));

  --measure: 38rem;
  --margin-col: 15.5rem;
  --margin-gap: 2.75rem;
  --toc-w: 16.5rem;
  --topbar-h: 3.5rem;
  --radius: 10px;

  --text: 1.125rem;
  --leading: 1.64;
}

@media (min-width: 1440px) {
  :root {
    --text: 1.1875rem;
    --measure: 39rem;
    --margin-col: 16.5rem;
  }
}

/* ---------------------------------------------------------------- Base --- */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: calc(var(--topbar-h) + 1.25rem);
  background: var(--bg);
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: var(--text);
  line-height: var(--leading);
  font-optical-sizing: auto;
  font-kerning: normal;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

::selection {
  background: color-mix(in oklab, var(--c-blue) 26%, transparent);
}

a {
  color: inherit;
  text-decoration-line: underline;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 0.19em;
  text-decoration-color: color-mix(in oklab, var(--accent-mark) 60%, transparent);
  transition: color 0.15s, text-decoration-color 0.15s;
}
a:hover {
  color: var(--accent);
  text-decoration-color: var(--accent-mark);
}

:focus-visible {
  outline: 2px solid var(--accent-mark);
  outline-offset: 2px;
  border-radius: 3px;
}

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

.icon {
  flex: none;
  display: block;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--ink);
  color: var(--bg);
  font: 600 0.875rem/1 var(--font-sans);
  border-radius: 6px;
  text-decoration: none;
}
.skip-link:focus {
  top: 0.75rem;
}

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

/* --------------------------------------------------------------- Topbar --- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  height: var(--topbar-h);
  background: color-mix(in oklab, var(--bg) 86%, transparent);
  -webkit-backdrop-filter: saturate(1.4) blur(14px);
  backdrop-filter: saturate(1.4) blur(14px);
  border-bottom: 1px solid var(--rule);
  font-family: var(--font-sans);
}

.topbar-inner {
  height: 100%;
  max-width: 1480px;
  margin: 0 auto;
  padding: 0 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--ink);
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.0625rem;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.brand:hover {
  color: var(--ink);
}
.logo {
  flex: none;
}
.logo-tile {
  fill: var(--ink);
}
.logo-line {
  stroke: var(--bg);
}
.logo-dot {
  fill: var(--bg);
}
.logo-spike {
  stroke: var(--c-orange);
}
/* Hovering the brand fires the neuron: the spike travels down the axon to the
   bouton, one way only, then the initial segment is ready again. */
@media (prefers-reduced-motion: no-preference) {
  .brand:hover .logo-spike {
    animation: logo-fire 0.9s ease-in;
  }
}
@keyframes logo-fire {
  55% {
    transform: translate(4.3px, 6px);
    opacity: 1;
  }
  56%,
  70% {
    transform: translate(4.3px, 6px);
    opacity: 0;
  }
  71% {
    transform: none;
    opacity: 0;
  }
  100% {
    transform: none;
    opacity: 1;
  }
}

.topbar-context {
  flex: 1;
  min-width: 0;
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  font-size: 0.8125rem;
  color: var(--ink-3);
  white-space: nowrap;
  overflow: hidden;
  padding-left: 0.85rem;
  margin-left: 0.15rem;
  border-left: 1px solid var(--rule);
  line-height: 1.2;
}
.ctx-chapter {
  color: var(--ink-2);
  font-weight: 600;
}
.ctx-section {
  overflow: hidden;
  text-overflow: ellipsis;
  opacity: 0;
  transform: translateY(3px);
  transition: opacity 0.2s, transform 0.2s;
}
.ctx-section.is-visible {
  opacity: 1;
  transform: none;
}
.topbar-spacer {
  flex: 1;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  margin-left: auto;
}

.icon-btn,
.text-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  height: 2.25rem;
  min-width: 2.25rem;
  padding: 0 0.5rem;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--ink-2);
  font: 550 0.8125rem/1 var(--font-sans);
  text-decoration: none;
  cursor: pointer;
}
.icon-btn:hover,
.text-btn:hover {
  background: var(--raised);
  color: var(--ink);
}
.text-btn .icon {
  width: 16px;
  height: 16px;
}

.theme-toggle .theme-icon {
  display: none;
}
:root[data-theme='light'] .theme-toggle .theme-icon-light,
:root[data-theme='dark'] .theme-toggle .theme-icon-dark {
  display: block;
}
:root:not([data-theme]) .theme-toggle .theme-icon-light {
  display: block;
}

.progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  pointer-events: none;
}
.progress-bar {
  height: 100%;
  width: 100%;
  transform-origin: 0 50%;
  transform: scaleX(var(--progress, 0));
  background: var(--accent-mark);
}

/* --------------------------------------------------------------- Layout --- */

.layout {
  max-width: 1480px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: var(--toc-w) minmax(0, 1fr);
}

.toc {
  position: sticky;
  top: var(--topbar-h);
  align-self: start;
  height: calc(100vh - var(--topbar-h));
  height: calc(100dvh - var(--topbar-h));
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  font-family: var(--font-sans);
  font-size: 0.84rem;
  line-height: 1.35;
  border-right: 1px solid var(--rule);
}
.toc-inner {
  padding: 1.75rem 1.25rem 3rem 1.5rem;
}
.toc-home {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--ink-3);
  text-decoration: none;
  font-size: 0.78rem;
  font-weight: 550;
  margin-bottom: 1.6rem;
}
.toc-home .icon {
  width: 15px;
  height: 15px;
}
.toc-kicker {
  margin: 0;
  color: var(--accent);
  font-size: 0.72rem;
  font-weight: 650;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.toc-title {
  margin: 0.15rem 0 1.25rem;
  font-family: var(--font-serif);
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.1;
}
.toc-title a {
  text-decoration: none;
}
.toc-list,
.toc-sub {
  list-style: none;
  margin: 0;
  padding: 0;
}
.toc-item {
  margin: 0.1rem 0;
}
.toc-link {
  display: flex;
  gap: 0.6rem;
  padding: 0.38rem 0.6rem;
  margin-left: -0.6rem;
  border-radius: 7px;
  color: var(--ink-2);
  text-decoration: none;
}
.toc-link:hover {
  background: var(--raised);
  color: var(--ink);
}
.toc-num {
  flex: none;
  width: 1.9rem;
  color: var(--ink-3);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
}
.toc-link.is-active {
  color: var(--ink);
  font-weight: 600;
  background: var(--raised);
}
.toc-link.is-active .toc-num {
  color: var(--accent);
}
.toc-sub {
  display: none;
  margin: 0.1rem 0 0.4rem 1.9rem;
  padding-left: 0.6rem;
  border-left: 1px solid var(--rule);
}
.toc-item.is-open > .toc-sub {
  display: block;
}
.toc-link-sub {
  padding: 0.26rem 0.6rem;
  margin-left: 0;
  font-size: 0.8rem;
  color: var(--ink-3);
}
.toc-link-sub.is-active {
  background: none;
  color: var(--ink);
  font-weight: 600;
}
.toc-scrim {
  display: none;
}

@media (max-width: 1199px) {
  .layout {
    display: block;
  }
  .toc {
    position: fixed;
    z-index: 60;
    top: 0;
    left: 0;
    bottom: 0;
    height: 100%;
    width: min(20rem, 86vw);
    background: var(--bg);
    border-right: 1px solid var(--rule);
    transform: translateX(-102%);
    transition: transform 0.24s cubic-bezier(0.2, 0.7, 0.2, 1);
    box-shadow: 0 0 0 transparent;
  }
  body.toc-open .toc {
    transform: none;
    box-shadow: 0 10px 40px rgb(0 0 0 / 0.22);
  }
  .toc-scrim {
    position: fixed;
    inset: 0;
    z-index: 55;
    background: rgb(0 0 0 / 0.28);
  }
  body.toc-open .toc-scrim {
    display: block;
  }
}
@media (min-width: 1200px) {
  .toc-toggle {
    display: none;
  }
}

/* ------------------------------------------------------- Chapter header --- */

.chapter {
  min-width: 0;
  outline: none;
}

.chapter-head,
.prose,
.chapter-nav {
  display: grid;
  grid-template-columns:
    [full-start] minmax(1.25rem, 1fr)
    [content-start] minmax(0, var(--measure))
    [content-end] minmax(0, var(--margin-gap))
    [margin-start] minmax(0, var(--margin-col))
    [margin-end] minmax(1.25rem, 1fr)
    [full-end];
}
.chapter-head > *,
.prose > *,
.prose > section.section > *,
.chapter-nav > * {
  grid-column: content;
}

.chapter-head {
  padding-top: clamp(2.5rem, 6vw, 5.5rem);
  padding-bottom: 0.5rem;
}
.chapter-kicker {
  margin: 0 0 0.6rem;
  font: 650 0.8rem/1 var(--font-sans);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}
.chapter-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(3rem, 2.1rem + 4.2vw, 5.25rem);
  line-height: 0.98;
  letter-spacing: -0.03em;
  text-wrap: balance;
}
.chapter-subtitle {
  margin: 0.9rem 0 0;
  font-size: clamp(1.2rem, 1.05rem + 0.6vw, 1.5rem);
  line-height: 1.35;
  font-style: italic;
  color: var(--ink-2);
  text-wrap: balance;
}
.chapter-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 2.25rem;
  margin: 2rem 0 0;
  padding: 1rem 0 0;
  border-top: 1px solid var(--rule);
  font: 0.84rem/1.45 var(--font-sans);
  color: var(--ink-2);
}
.chapter-meta div {
  max-width: 26rem;
}
.chapter-meta dt {
  font-size: 0.7rem;
  font-weight: 650;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: 0.15rem;
}
.chapter-meta dd {
  margin: 0;
}

/* ---------------------------------------------------------------- Prose --- */

.prose {
  padding-bottom: 3rem;
}
.prose > section.section {
  grid-column: full;
  display: grid;
  grid-template-columns: subgrid;
}

.prose p,
.prose li {
  font-variant-numeric: oldstyle-nums proportional-nums;
  hyphens: auto;
  -webkit-hyphens: auto;
  text-wrap: pretty;
}
.prose p {
  margin: 0 0 1.05em;
}
.prose strong {
  font-weight: 650;
}
.prose dfn {
  font-style: normal;
  font-weight: 650;
}
.prose em dfn,
.prose dfn em {
  font-style: italic;
}
.prose .sc {
  font-variant-caps: all-small-caps;
  letter-spacing: 0.04em;
}
.nowrap {
  white-space: nowrap;
}

.prose h2 {
  position: relative;
  margin: 3.4rem 0 1.15rem;
  font-family: var(--font-serif);
  font-size: clamp(1.7rem, 1.45rem + 0.9vw, 2.15rem);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.02em;
  text-wrap: balance;
}
.prose h2 .sec-num {
  display: block;
  margin-bottom: 0.4rem;
  font: 600 0.82rem/1 var(--font-sans);
  letter-spacing: 0.06em;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.prose .sec-source {
  margin: -0.55rem 0 1.5rem;
  font: 0.78rem/1.4 var(--font-sans);
  color: var(--ink-3);
}
.prose h2 + .sec-source + p,
.prose h2 + p {
  margin-top: 0;
}

.prose h3 {
  margin: 2.4rem 0 0.7rem;
  font: 650 1.08rem/1.3 var(--font-sans);
  letter-spacing: -0.01em;
  text-wrap: balance;
}
.prose h4 {
  margin: 1.8rem 0 0.4rem;
  font: 650 0.95rem/1.3 var(--font-sans);
}

.heading-anchor {
  position: absolute;
  left: -1.4rem;
  bottom: 0.1em;
  width: 1.2rem;
  font: 500 1rem/1 var(--font-sans);
  color: var(--ink-3);
  text-decoration: none;
  opacity: 0;
  transition: opacity 0.15s;
}
.prose h2:hover .heading-anchor,
.prose h3:hover .heading-anchor,
.heading-anchor:focus {
  opacity: 1;
}
.prose h3 {
  position: relative;
}

.prose ul,
.prose ol {
  margin: 0 0 1.1em;
  padding-left: 1.35em;
}
.prose li {
  margin: 0.3em 0;
  padding-left: 0.15em;
}
.prose ul > li::marker {
  color: var(--ink-3);
}
.prose ol > li::marker {
  color: var(--ink-3);
  font: 600 0.88em var(--font-sans);
  font-variant-numeric: tabular-nums;
}

.prose blockquote {
  margin: 1.5rem 0;
  padding: 0 0 0 1.25rem;
  border-left: 2px solid var(--rule-2);
  color: var(--ink-2);
  font-style: italic;
}
.prose blockquote.epigraph {
  border: 0;
  padding: 0;
  margin: 2.5rem 0 0.5rem;
  font-size: 1.15em;
  line-height: 1.5;
}
.prose blockquote.epigraph p:last-child {
  margin-bottom: 0;
}
.prose blockquote.epigraph::after {
  content: '— ' attr(data-cite);
  display: block;
  margin-top: 0.6rem;
  font: normal 0.85rem/1.4 var(--font-sans);
  color: var(--ink-3);
}

.prose hr {
  border: 0;
  height: 1px;
  background: var(--rule);
  margin: 2.5rem 0;
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.84em;
  padding: 0.1em 0.32em;
  border-radius: 5px;
  background: var(--code-bg);
  font-variant-ligatures: none;
}
.prose pre {
  margin: 1.5rem 0;
  padding: 1rem 1.2rem;
  overflow-x: auto;
  border-radius: var(--radius);
  background: var(--code-bg);
  font-size: 0.86rem;
  line-height: 1.6;
}
.prose pre code {
  padding: 0;
  background: none;
  font-size: inherit;
}

/* --------------------------------------------------------------- Tables --- */

.table-wrap {
  overflow-x: auto;
  margin: 1.5rem 0;
}
.prose table {
  width: 100%;
  border-collapse: collapse;
  font: 0.875rem/1.45 var(--font-sans);
  font-variant-numeric: tabular-nums lining-nums;
}
.prose th {
  text-align: left;
  font-size: 0.7rem;
  font-weight: 650;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-3);
  padding: 0 0.9rem 0.55rem 0;
  border-bottom: 1px solid var(--rule-2);
  vertical-align: bottom;
}
.prose td {
  padding: 0.6rem 0.9rem 0.6rem 0;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}
.prose td:first-child {
  font-weight: 600;
  color: var(--ink);
}
.prose tr:last-child td {
  border-bottom: 0;
}
.prose td p {
  margin: 0;
}

.table-notes {
  margin: -0.75rem 0 1.5rem;
  padding-top: 0.6rem;
  border-top: 1px solid var(--rule);
  font: 0.76rem/1.5 var(--font-sans);
  color: var(--ink-2);
  columns: 2 18rem;
  column-gap: 2rem;
}
.table-note {
  margin: 0 0 0.35rem;
  break-inside: avoid;
}
.table-note:target {
  animation: flash 1.6s ease-out;
}

/* -------------------------------------------------------------- Figures --- */

.fig {
  margin: 2.4rem 0 2.6rem;
}
.prose .fig[data-size='wide'],
.prose .fig-table[data-size='wide'] {
  grid-column: content-start / margin-end;
}
.fig-media {
  position: relative;
}
.fig-media svg {
  display: block;
  width: 100%;
  height: auto;
  overflow: visible;
}
.fig figcaption {
  max-width: var(--measure);
  margin-top: 1rem;
  font: 0.86rem/1.55 var(--font-sans);
  color: var(--ink-2);
  text-wrap: pretty;
}
.fig-table figcaption {
  margin: 0 0 0.25rem;
}
.fig-label {
  font-weight: 650;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
  margin-right: 0.15em;
}
.fig figcaption strong {
  font-weight: 650;
  color: var(--ink);
}

/* On phones, detailed figures keep a legible minimum size and scroll sideways. */
@media (max-width: 700px) {
  .fig-media {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    margin: 0 -1.25rem;
    padding: 0 1.25rem;
    scrollbar-width: thin;
  }
  .fig-media svg {
    min-width: 560px;
  }
  .fig[data-size='wide'] .fig-media svg {
    min-width: 680px;
  }
}

/* Figure internals: interactive highlights (web only) */
.figure-svg .hl {
  transition: opacity 0.18s;
}
.figure-svg.has-focus .hl:not(.is-focus) {
  opacity: 0.25;
}
.figure-svg .hover-target {
  cursor: default;
}

/* ------------------------------------------------------------- Callouts --- */

.principle,
.callout,
.summary {
  margin: 2rem 0;
  border-radius: var(--radius);
}

.principle {
  position: relative;
  padding: 1.15rem 1.35rem 1.2rem;
  background: var(--wash-accent);
  box-shadow: inset 3px 0 0 var(--accent-mark);
}
.principle-head {
  margin-bottom: 0.4rem;
  line-height: 1.25;
}
.principle-label {
  display: block;
  font: 650 0.72rem/1.2 var(--font-sans);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
}
.principle-name {
  display: block;
  margin-top: 0.25rem;
  font: 600 1.28rem/1.2 var(--font-serif);
  letter-spacing: -0.012em;
}
.principle p:last-child,
.callout p:last-child,
.summary p:last-child {
  margin-bottom: 0;
}

.callout {
  padding: 1.1rem 1.35rem 1.2rem;
  font-family: var(--font-sans);
  font-size: 0.93rem;
  line-height: 1.62;
}
.callout p,
.callout li {
  font-variant-numeric: normal;
  hyphens: manual;
}
.callout-head {
  margin-bottom: 0.45rem;
  line-height: 1.3;
}
.callout-label {
  display: block;
  font: 650 0.72rem/1.2 var(--font-sans);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.callout-title {
  display: block;
  margin-top: 0.2rem;
  font-weight: 650;
  font-size: 1.02rem;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.lens {
  background: var(--wash-blue);
  box-shadow: inset 3px 0 0 var(--c-blue);
}
.lens .callout-label {
  color: color-mix(in oklab, var(--c-blue-deep) 80%, var(--ink));
}
:root[data-theme='dark'] .lens .callout-label {
  color: var(--c-blue-deep);
}
.lens .callout-label::before {
  content: '';
  display: inline-block;
  width: 0.62rem;
  height: 0.62rem;
  margin-right: 0.45rem;
  border: 1.6px solid currentColor;
  border-radius: 50%;
  vertical-align: -0.04rem;
  box-shadow: 0.24rem 0.24rem 0 -0.12rem currentColor;
}
.box {
  background: var(--raised);
}
.box .callout-label {
  color: var(--ink-3);
}
.callout ul,
.callout ol {
  padding-left: 1.2em;
}
.callout code {
  font-size: 0.86em;
}

.summary {
  margin: 2.5rem 0 2.75rem;
  padding: 1.35rem 1.5rem 1.4rem;
  border: 1px solid var(--rule);
  font-family: var(--font-sans);
  font-size: 0.94rem;
  line-height: 1.58;
}
.summary .summary-title {
  margin: 0 0 0.75rem;
  font: 650 0.75rem/1.2 var(--font-sans);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.summary ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.summary li {
  position: relative;
  margin: 0.45rem 0;
  padding-left: 1.5rem;
  font-variant-numeric: normal;
  hyphens: manual;
}
.summary li::before {
  content: '';
  position: absolute;
  left: 0.15rem;
  top: 0.62em;
  width: 0.55rem;
  height: 2px;
  border-radius: 2px;
  background: var(--accent-mark);
}

/* ------------------------------------------------------------ Sidenotes --- */

.fn-ref {
  font: 650 0.68em/0 var(--font-sans);
  vertical-align: 0.55em;
  margin-left: 0.06em;
}
.fn-ref a {
  color: var(--accent);
  text-decoration: none;
  padding: 0 0.1em;
}
.sidenote {
  font: 0.79rem/1.5 var(--font-sans);
  color: var(--ink-2);
  font-variant-numeric: normal;
  hyphens: manual;
  text-wrap: pretty;
}
.sn-num {
  font-weight: 700;
  color: var(--accent);
  margin-right: 0.15em;
  font-variant-numeric: tabular-nums;
}
.sidenote a {
  word-break: break-word;
}

@media (min-width: 1040px) {
  .sidenote {
    float: right;
    clear: right;
    position: relative;
    width: var(--margin-col);
    margin-right: calc(-1 * (var(--margin-col) + var(--margin-gap)));
    margin-top: 0.2rem;
    margin-bottom: 1rem;
  }
  .sidenote:target,
  .sidenote.is-flash {
    animation: flash 1.6s ease-out;
  }
  li .sidenote {
    margin-right: calc(-1 * (var(--margin-col) + var(--margin-gap)) - 1.5em);
  }
  .callout .sidenote,
  .principle .sidenote {
    margin-right: calc(-1 * (var(--margin-col) + var(--margin-gap)) - 1.35rem);
  }
}
@keyframes flash {
  0% {
    background: color-mix(in oklab, var(--accent-mark) 22%, transparent);
  }
  100% {
    background: transparent;
  }
}
@media (max-width: 1039px) {
  /* No margin column: sidenotes open inline, so give the text the full width. */
  :root {
    --margin-col: 0rem;
    --margin-gap: 0rem;
  }
  .sidenote {
    display: none;
  }
  .sidenote:target,
  .sidenote.is-open {
    display: block;
    margin: 0.6rem 0 0.9rem;
    padding: 0.7rem 0.9rem;
    border-radius: 8px;
    background: var(--raised);
  }
}

/* ------------------------------------------------------- Chapter footer --- */

.chapter-nav {
  padding: 1rem 0 4.5rem;
}
.chapter-nav-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
@media (max-width: 640px) {
  .chapter-nav-inner {
    grid-template-columns: 1fr;
  }
}
.chapter-nav-link {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding: 1.1rem 1.3rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  text-decoration: none;
  font-family: var(--font-sans);
  margin-top: 0.75rem;
}
a.chapter-nav-link:hover {
  border-color: var(--rule-2);
  background: var(--raised);
  color: var(--ink);
}
.chapter-nav-link.next {
  text-align: right;
  align-items: flex-end;
}
.chapter-nav-dir {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.72rem;
  font-weight: 650;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.chapter-nav-dir .icon {
  width: 15px;
  height: 15px;
}
.chapter-nav-title {
  font: 600 1.15rem/1.25 var(--font-serif);
  color: var(--ink);
}
.chapter-nav-link.soon {
  border-style: dashed;
}
.chapter-nav-link.soon .chapter-nav-title {
  color: var(--ink-3);
}

/* --------------------------------------------------------- Site footer --- */

.site-footer {
  border-top: 1px solid var(--rule);
  font: 0.8rem/1.55 var(--font-sans);
  color: var(--ink-3);
}
.site-footer-inner {
  max-width: 1480px;
  margin: 0 auto;
  padding: 2.25rem 1.5rem 3rem;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 1rem 2.5rem;
  align-items: start;
}
.footer-brand {
  display: flex;
  gap: 0.75rem;
  margin: 0;
  color: var(--ink-2);
}
.footer-brand strong {
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  font-weight: 600;
}
.footer-note,
.footer-legal {
  margin: 0;
  max-width: 36rem;
}
.footer-legal {
  text-align: right;
}
@media (max-width: 900px) {
  .site-footer-inner {
    grid-template-columns: 1fr;
  }
  .footer-legal {
    text-align: left;
  }
}

/* -------------------------------------------------------------- Home page --- */

.home {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 1.5rem 5rem;
}
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: 2rem 4rem;
  align-items: center;
  padding: clamp(2.5rem, 7vw, 6.5rem) 0 clamp(2rem, 5vw, 4rem);
}
.hero-kicker {
  margin: 0 0 1rem;
  font: 650 0.8rem/1 var(--font-sans);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}
.hero-title {
  margin: 0;
  font-weight: 600;
  font-size: clamp(2.9rem, 1.9rem + 4vw, 5.1rem);
  line-height: 0.98;
  letter-spacing: -0.032em;
  text-wrap: balance;
}
.hero-subtitle {
  margin: 0.9rem 0 0;
  font-size: clamp(1.25rem, 1.05rem + 0.8vw, 1.65rem);
  font-style: italic;
  line-height: 1.3;
  color: var(--ink-2);
  text-wrap: balance;
}
.hero-lede {
  margin: 1.6rem 0 0;
  max-width: 34rem;
  font-size: 1.13rem;
  color: var(--ink-2);
  text-wrap: pretty;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 2rem;
}
.hero-byline {
  margin: 1.4rem 0 0;
  font: 0.85rem/1.4 var(--font-sans);
  color: var(--ink-3);
}
.hero-art {
  position: relative;
  aspect-ratio: 1 / 1.08;
  border-radius: 18px;
  overflow: hidden;
  background: radial-gradient(120% 90% at 30% 20%, color-mix(in oklab, var(--c-tissue) 70%, var(--bg)), var(--bg));
  border: 1px solid var(--rule);
}
.hero-art svg {
  display: block;
  width: 100%;
  height: 100%;
}
@media (max-width: 860px) {
  .hero {
    grid-template-columns: 1fr;
  }
  .hero-art {
    max-width: 30rem;
    width: 100%;
    order: -1;
    aspect-ratio: 4 / 3;
  }
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 2.75rem;
  padding: 0.65rem 1.1rem;
  border-radius: 10px;
  border: 1px solid var(--rule-2);
  font: 600 0.9rem/1.2 var(--font-sans);
  color: var(--ink);
  text-decoration: none;
  background: transparent;
}
.btn .icon {
  width: 17px;
  height: 17px;
}
.btn:hover {
  background: var(--raised);
  color: var(--ink);
}
.btn-primary {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--bg);
}
.btn-primary:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg);
}
:root[data-theme='dark'] .btn-primary:hover {
  color: #1d1c1a;
}

.home-intro {
  display: block;
  max-width: 44rem;
  padding: 1rem 0 1rem;
  border-top: 1px solid var(--rule);
}
.home-intro > *,
.home-intro section.section > * {
  grid-column: auto;
}
.home-intro section.section {
  display: block;
}
.home-intro h2 {
  margin: 2.2rem 0 0.8rem;
  font-size: 1.6rem;
}

.contents {
  margin-top: 2.5rem;
}
.contents-heading {
  margin: 0 0 1rem;
  font: 650 0.78rem/1.2 var(--font-sans);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.contents-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--rule);
}
.contents-row {
  display: grid;
  grid-template-columns: 3.2rem minmax(0, 1fr) auto;
  gap: 1rem;
  align-items: baseline;
  padding: 1.05rem 0.25rem;
  border-bottom: 1px solid var(--rule);
  text-decoration: none;
  color: var(--ink);
}
a.contents-row:hover {
  background: var(--raised);
  color: var(--ink);
}
.contents-num {
  font: 600 1.6rem/1 var(--font-serif);
  color: var(--accent);
  font-variant-numeric: lining-nums tabular-nums;
  text-align: right;
}
.contents-body {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}
.contents-title {
  font: 600 1.35rem/1.2 var(--font-serif);
  letter-spacing: -0.01em;
}
.contents-summary {
  font: 0.86rem/1.45 var(--font-sans);
  color: var(--ink-2);
}
.contents-status {
  font: 650 0.68rem/1 var(--font-sans);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-3);
  padding: 0.35rem 0.55rem;
  border-radius: 999px;
  border: 1px solid var(--rule);
  white-space: nowrap;
}
.contents-status.is-ready {
  color: var(--bg);
  background: var(--accent);
  border-color: var(--accent);
}
:root[data-theme='dark'] .contents-status.is-ready {
  color: #1d1c1a;
}
.is-planned .contents-num,
.is-planned .contents-title {
  color: var(--ink-3);
}

/* ---------------------------------------------------------------- 404 --- */

.not-found {
  max-width: 40rem;
  margin: 0 auto;
  padding: 8rem 1.5rem 10rem;
}

/* ---------------------------------------------------------- Responsive --- */

@media (max-width: 640px) {
  :root {
    --text: 1.0625rem;
    --leading: 1.6;
  }
  .brand-name {
    display: none;
  }
  .hide-sm {
    display: none;
  }
  .topbar-context {
    border-left: 0;
    padding-left: 0;
  }
  .principle,
  .callout,
  .summary {
    margin-left: -0.5rem;
    margin-right: -0.5rem;
    padding-left: 1.1rem;
    padding-right: 1.1rem;
  }
}

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

@media print {
  .topbar,
  .toc,
  .chapter-nav,
  .site-footer,
  .skip-link {
    display: none !important;
  }
  .layout {
    display: block;
  }
}

/* ------------------------------------------------------------ Cover art --- */

.cover-art .spike,
.cover-art .spike-glow {
  animation: spike-travel 3.2s cubic-bezier(0.45, 0.05, 0.55, 0.95) infinite;
}
@keyframes spike-travel {
  0% {
    stroke-dashoffset: 30;
    opacity: 0;
  }
  8% {
    opacity: 1;
  }
  70% {
    stroke-dashoffset: -260;
    opacity: 1;
  }
  80%,
  100% {
    stroke-dashoffset: -300;
    opacity: 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .cover-art .spike,
  .cover-art .spike-glow {
    animation: none;
  }
}