/* Source CSS is split by layer. scripts/build-site.mjs inlines these imports
   into a single build/styles.css file. */
/* Theme tokens */
:root {
  color-scheme: light;
  --bg: #f8f6f0;
  --panel: #ffffff;
  --text: #17201d;
  --muted: #53635d;
  --border: #d8ded8;
  --accent: #0f766e;
  --accent-strong: #134e4a;
  --success: #0f766e;
  --warning: #b45309;
  --danger: #991b1b;
  --code-bg: #17201d;
  --code-text: #ecfdf5;
  --syntax-comment: #a9b8b2;
  --syntax-keyword: #7dd3fc;
  --syntax-literal: #fda4af;
  --syntax-property: #99f6e4;
  --syntax-string: #fde68a;
  --syntax-title: #c4b5fd;
  --syntax-meta: #f9a8d4;
  --syntax-addition: #86efac;
  --syntax-deletion: #fca5a5;
  --font-ui:
    ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  --font-serif: Georgia, Cambria, "Times New Roman", serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --shadow: 0 18px 40px rgb(23 32 29 / 10%);
  font-family: var(--font-ui);
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #121514;
  --panel: #1c211f;
  --text: #edf3ef;
  --muted: #a8b8b0;
  --border: #35413c;
  --accent: #5eead4;
  --accent-strong: #99f6e4;
  --success: #5eead4;
  --warning: #fbbf24;
  --danger: #f87171;
  --code-bg: #080b0a;
  --code-text: #e7fff8;
  --syntax-comment: #a7b5af;
  --syntax-keyword: #8bd5ff;
  --syntax-literal: #ffabb6;
  --syntax-property: #a2f3e3;
  --syntax-string: #ffe28f;
  --syntax-title: #ccbeff;
  --syntax-meta: #ffb0dd;
  --syntax-addition: #93efb0;
  --syntax-deletion: #ffaaaa;
  --shadow: 0 18px 40px rgb(0 0 0 / 24%);
}

[data-theme="sepia"] {
  color-scheme: light;
  --bg: #f4ecd9;
  --panel: #fffaf0;
  --text: #2a2118;
  --muted: #67594a;
  --border: #d9c9aa;
  --accent: #8a4b21;
  --accent-strong: #5e3218;
  --success: #2f6f55;
  --warning: #8a4b21;
  --danger: #9f2f2f;
  --code-bg: #2d241c;
  --code-text: #fff6e5;
  --syntax-comment: #c7b9a3;
  --syntax-keyword: #93cfff;
  --syntax-literal: #ffb4a8;
  --syntax-property: #a7e3c1;
  --syntax-string: #ffd98a;
  --syntax-title: #dab9ff;
  --syntax-meta: #f3b1d2;
  --syntax-addition: #a7e3c1;
  --syntax-deletion: #ffb4a8;
}

[data-theme="contrast"] {
  color-scheme: dark;
  --bg: #000000;
  --panel: #050505;
  --text: #ffffff;
  --muted: #f2f2f2;
  --border: #ffffff;
  --accent: #ffdd00;
  --accent-strong: #ffffff;
  --success: #00ff99;
  --warning: #ffdd00;
  --danger: #ff4f4f;
  --code-bg: #000000;
  --code-text: #ffffff;
  --syntax-comment: #e6e6e6;
  --syntax-keyword: #ffdd00;
  --syntax-literal: #ff9e9e;
  --syntax-property: #00ff99;
  --syntax-string: #ffffff;
  --syntax-title: #7dd3fc;
  --syntax-meta: #ff9ee5;
  --syntax-addition: #00ff99;
  --syntax-deletion: #ff8a8a;
}

[data-theme="calm"] {
  color-scheme: light;
  --bg: #eef7f3;
  --panel: #fbfffd;
  --text: #16251f;
  --muted: #52685e;
  --border: #bfd8cd;
  --accent: #2f6f93;
  --accent-strong: #214f68;
  --code-bg: #17242b;
  --success: #2f6f55;
  --warning: #9f641c;
  --danger: #9f2f3f;
  --code-text: #e9f8ff;
  --syntax-comment: #a9bac2;
  --syntax-keyword: #8bd5ff;
  --syntax-literal: #ffb2bd;
  --syntax-property: #9fe5d3;
  --syntax-string: #f5dc9b;
  --syntax-title: #c9bcff;
  --syntax-meta: #efb4d5;
  --syntax-addition: #9fe5d3;
  --syntax-deletion: #ffb2bd;
}

/* Base document styles */
* {
  box-sizing: border-box;
}
html {
  background: var(--bg);
  scroll-behavior: smooth;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  font-size: 18px;
  font-weight: 400;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a {
  color: var(--accent-strong);
}
a:hover {
  color: var(--accent);
}
.visually-hidden {
  block-size: 1px;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  inline-size: 1px;
  overflow: hidden;
  position: absolute;
  white-space: nowrap;
}
.skip-link {
  position: absolute;
  left: 1rem;
  top: -10rem;
  z-index: 10;
  background: var(--accent);
  color: var(--panel);
  padding: 0.5rem 0.75rem;
}
.skip-link:focus {
  top: 1rem;
}

/* Native, cross-document motion for same-origin navigation. */
@view-transition {
  navigation: auto;
}

@media (prefers-reduced-motion: no-preference) {
  .brand {
    view-transition-name: site-brand;
  }

  ::view-transition-image-pair(root) {
    isolation: auto;
  }

  ::view-transition-old(root) {
    animation: book-page-out 130ms cubic-bezier(0.4, 0, 1, 1) both;
    mix-blend-mode: normal;
  }

  ::view-transition-new(root) {
    animation: book-page-in 260ms 45ms cubic-bezier(0.22, 1, 0.36, 1) both;
    mix-blend-mode: normal;
  }

  ::view-transition-group(site-brand) {
    animation-duration: 260ms;
    animation-timing-function: cubic-bezier(0.22, 1, 0.36, 1);
  }

  ::view-transition-old(site-brand),
  ::view-transition-new(site-brand) {
    animation: none;
    mix-blend-mode: normal;
  }
}

@media (prefers-reduced-motion: reduce) {
  @view-transition {
    navigation: none;
  }
}

@keyframes book-page-out {
  to {
    opacity: 0;
    transform: translateY(-0.2rem);
  }
}

@keyframes book-page-in {
  from {
    opacity: 0;
    transform: translateY(0.45rem);
  }
}

/* Site layout, navigation, home page, and book chrome */
.site-header {
  align-items: center;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr auto;
  padding: 0.85rem clamp(1rem, 3vw, 2.5rem);
  position: sticky;
  top: 0;
  z-index: 5;
}
.brand {
  color: var(--text);
  font-weight: 700;
  text-decoration: none;
}
.header-actions {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  column-gap: 1.25rem;
  row-gap: 0.75rem;
  justify-content: flex-end;
  position: relative;
}
.site-header nav {
  display: flex;
  gap: 1.15rem;
  font-size: 0.95rem;
}
.site-header nav a {
  text-decoration: none;
}
.learning-launchers {
  align-items: center;
  border-inline-start: 1px solid var(--border);
  display: flex;
  gap: 0.25rem;
  padding-inline-start: 0.75rem;
}
.learning-launchers[hidden],
.learning-toggle[hidden] {
  display: none;
}
.learning-toggle {
  align-items: center;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 0.35rem;
  color: var(--muted);
  cursor: pointer;
  display: inline-flex;
  flex-direction: column;
  gap: 0.15rem;
  inline-size: 4rem;
  min-block-size: 3rem;
  padding: 0.3rem;
  font: 600 0.68rem/1.2 var(--font-ui);
}
.learning-launcher-icon {
  block-size: 1.3rem;
  fill: none;
  flex: 0 0 auto;
  inline-size: 1.3rem;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.6;
}
.learning-toggle:hover {
  background: var(--bg);
  color: var(--accent-strong);
}
.learning-toggle[aria-expanded="true"] {
  background: color-mix(in srgb, var(--accent) 12%, var(--panel));
  border-color: var(--accent-strong);
  color: var(--accent-strong);
}
.learning-toggle:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 2px;
}
.theme-picker {
  align-items: center;
  display: inline-flex;
  font-size: 0.82rem;
  gap: 0.4rem;
  justify-self: start;
}
.theme-picker-icon {
  color: var(--muted);
  flex: 0 0 auto;
  inline-size: 1rem;
  pointer-events: none;
}
.theme-picker select {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text);
  font: inherit;
  max-inline-size: 8.5rem;
  padding: 0.32rem 0.45rem;
}
.theme-picker select:focus-visible {
  border-color: var(--accent);
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.site-tools-panel {
  align-items: stretch;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.6rem;
  box-shadow: var(--shadow);
  display: none;
  flex-direction: column;
  gap: 0.75rem;
  inline-size: min(32rem, calc(100vw - 2rem));
  inset-block-start: calc(100% + 0.7rem);
  inset-inline-end: 0;
  padding: 0.75rem;
  position: absolute;
  z-index: 8;
}
[data-tools-open="true"] .site-tools-panel {
  display: flex;
}
.tools-toggle,
.edit-toggle,
.feedback-controls button,
.feedback-controls a {
  background: var(--accent-strong);
  border: 1px solid var(--accent-strong);
  border-radius: 0.35rem;
  color: var(--panel);
  cursor: pointer;
  font: 700 0.82rem/1.15 var(--font-ui);
  padding: 0.36rem 0.65rem;
  text-decoration: none;
}
.tools-toggle {
  align-items: center;
  gap: 0.4rem;
}
.tools-toggle:not([hidden]) {
  display: inline-flex;
}
.tools-toggle-chevron {
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.5;
  transition: transform 140ms ease;
}
.tools-toggle[aria-expanded="true"] .tools-toggle-chevron {
  transform: rotate(180deg);
}
.feedback-overview-link {
  align-items: center;
  background: color-mix(in srgb, var(--accent) 8%, var(--panel));
  border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--border));
  border-radius: 0.45rem;
  color: var(--text);
  display: grid;
  gap: 0.65rem;
  grid-template-columns: auto minmax(0, 1fr);
  padding: 0.7rem 0.8rem;
  text-decoration: none;
}
.feedback-overview-link[hidden] {
  display: none;
}
.feedback-overview-link svg {
  fill: none;
  stroke: var(--accent-strong);
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.6;
}
.feedback-overview-link span {
  display: grid;
  line-height: 1.3;
}
.feedback-overview-link small {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 500;
}
.feedback-overview-link:hover {
  background: color-mix(in srgb, var(--accent) 14%, var(--panel));
  border-color: var(--accent);
  color: var(--text);
}
.feedback-overview-link:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.feedback-controls a {
  align-items: center;
  display: inline-flex;
  justify-content: center;
}
.feedback-controls [hidden] {
  display: none;
}
.tools-toggle:hover,
.edit-toggle:hover,
.feedback-controls button:hover,
.feedback-controls a:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--panel);
}
.feedback-controls {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-left: 0;
  padding-left: 0;
}
.feedback-controls[hidden] {
  display: none;
}
.feedback-controls span {
  color: var(--muted);
  font-size: 0.85rem;
  max-width: 12rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.feedback-controls button,
.feedback-controls a {
  background: transparent;
  color: var(--text);
  min-block-size: 2rem;
  padding: 0.3rem 0.62rem;
}
.feedback-controls select {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  color: var(--text);
  font: inherit;
  font-size: 0.85rem;
  padding: 0.28rem 0.45rem;
}
.feedback-controls button:hover,
.feedback-controls a:hover {
  color: var(--panel);
}
.site-footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  margin-top: 4rem;
  padding: 1.5rem clamp(1rem, 3vw, 2.5rem);
  text-align: center;
}
.site-footer p {
  margin: 0;
}
.hero {
  align-items: start;
  display: grid;
  gap: 2rem;
  grid-template-columns: minmax(0, 1fr) minmax(14rem, 22rem);
  margin: 0 auto;
  max-width: 72rem;
  padding: clamp(2rem, 6vw, 5rem) clamp(1rem, 3vw, 2.5rem);
}
.hero-copy h1 {
  font-family: var(--font-serif);
  font-size: clamp(2.6rem, 6vw, 5.25rem);
  font-weight: 500;
  letter-spacing: 0;
  line-height: 1;
  margin: 0.25rem 0 1rem;
  max-width: 11ch;
}
.hero-copy p:not(.eyebrow) {
  color: var(--muted);
  max-width: 42rem;
}
.eyebrow,
.chapter-kicker,
.book-navigation summary {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  margin: 0 0 0.75rem;
  text-transform: uppercase;
}
.book-navigation summary {
  cursor: default;
  list-style: none;
}
.book-navigation summary::-webkit-details-marker {
  display: none;
}
.book-panel-icon {
  display: none;
}
.book-navigation-mobile-heading {
  display: none;
}
.primary-link {
  background: var(--accent-strong);
  border-radius: 0.35rem;
  color: var(--panel);
  display: inline-flex;
  font-weight: 700;
  margin-top: 1rem;
  padding: 0.65rem 0.9rem;
  text-decoration: none;
}
.primary-link:hover {
  color: var(--panel);
  background: var(--accent);
}
.cover-panel {
  display: grid;
  gap: 1rem;
}
.cover-panel img {
  aspect-ratio: 3 / 4;
  background: #ffffff;
  border-radius: 0.5rem;
  box-shadow: var(--shadow);
  display: block;
  height: auto;
  width: 100%;
}
.course-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  box-shadow: var(--shadow);
  padding: 1rem;
}
.course-panel dl,
.course-panel dd {
  margin: 0;
}
.course-panel div + div {
  border-top: 1px solid var(--border);
  margin-top: 0.8rem;
  padding-top: 0.8rem;
}
.course-panel dt {
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
}
.course-panel dd {
  font-weight: 700;
  line-height: 1.35;
  margin-top: 0.2rem;
}
.home-main {
  margin: 0 auto 4rem;
  max-width: 88rem;
  padding: 0 clamp(1rem, 3vw, 2.5rem);
}
.home-main h2 {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 500;
  line-height: 1.15;
}
.project-callout {
  align-items: center;
  background: var(--panel);
  border: 1px solid var(--border);
  border-left: 0.4rem solid var(--accent-strong);
  box-shadow: var(--shadow);
  display: grid;
  gap: clamp(1rem, 3vw, 2.5rem);
  grid-template-columns: minmax(14rem, 0.9fr) minmax(18rem, 1.35fr) auto;
  margin: 0 0 clamp(2.5rem, 6vw, 5rem);
  padding: clamp(1.1rem, 2.5vw, 1.75rem);
}
.project-callout .eyebrow {
  margin-bottom: 0.35rem;
}
.home-main .project-callout h2 {
  font-size: clamp(1.45rem, 2.5vw, 2rem);
  margin: 0;
}
.project-callout > p {
  color: var(--muted);
  font-family: var(--font-serif);
  line-height: 1.5;
  margin: 0;
}
.project-callout > a {
  border-bottom: 2px solid var(--accent);
  color: var(--text);
  font-size: 0.86rem;
  font-weight: 750;
  padding: 0.35rem 0;
  text-decoration: none;
  white-space: nowrap;
}
.project-callout > a span {
  color: var(--accent-strong);
  margin-left: 0.35rem;
}
.book-part {
  margin-top: 2rem;
}
.book-part-header {
  align-items: baseline;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.7rem;
}
.book-part-header h3 {
  font-family: var(--font-serif);
  font-size: 1.45rem;
  font-weight: 500;
  line-height: 1.2;
  margin: 0;
}
.book-part-header a {
  color: var(--text);
  text-decoration-color: var(--accent);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.16em;
}
.book-part-header a:hover {
  color: var(--accent-strong);
}
.chapter-grid {
  display: grid;
  gap: 0.85rem;
  grid-template-columns: repeat(auto-fit, minmax(min(20rem, 100%), 1fr));
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
}
.chapter-grid a,
.chapter-grid .chapter-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-left: 0.35rem solid var(--accent);
  border-radius: 0.35rem;
  color: var(--text);
  display: block;
  height: 100%;
  min-height: 8rem;
  padding: 1rem;
  text-decoration: none;
}
.chapter-grid .is-unpublished .chapter-card {
  border-left-color: var(--border);
  color: var(--muted);
  cursor: default;
  opacity: 0.68;
}
.chapter-grid span {
  color: var(--muted);
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}
.chapter-grid strong {
  display: block;
  font-size: 1.2rem;
  font-weight: 650;
  line-height: 1.3;
}
.chapter-grid em {
  color: var(--muted);
  display: block;
  font-size: 0.85rem;
  font-style: normal;
  font-weight: 600;
  margin-top: 0.85rem;
}
.chapter-grid em:empty {
  display: none;
}
.home-case-studies {
  border-top: 1px solid var(--border);
  margin-top: clamp(3.5rem, 8vw, 7rem);
  padding-top: clamp(1.5rem, 3vw, 2.5rem);
}
.home-case-studies-header {
  align-items: end;
  display: grid;
  gap: clamp(1rem, 3vw, 2.5rem);
  grid-template-columns: minmax(13rem, 0.8fr) minmax(18rem, 1.2fr) auto;
}
.home-case-studies-header .eyebrow {
  margin-bottom: 0.35rem;
}
.home-main .home-case-studies-header h2 {
  margin: 0;
}
.home-case-studies-header > p {
  color: var(--muted);
  font-family: var(--font-serif);
  line-height: 1.5;
  margin: 0;
}
.home-case-studies-header > a {
  border-bottom: 2px solid var(--accent);
  color: var(--text);
  font-size: 0.86rem;
  font-weight: 750;
  padding: 0.35rem 0;
  text-decoration: none;
  white-space: nowrap;
}
.home-case-studies-header > a span {
  color: var(--accent-strong);
  margin-left: 0.35rem;
}
.home-case-study-list {
  list-style: none;
  margin: clamp(1.75rem, 4vw, 3rem) 0 0;
  padding: 0;
}
.home-case-study-list li {
  border-top: 1px solid var(--border);
}
.home-case-study-list li:last-child {
  border-bottom: 1px solid var(--border);
}
.home-case-study-list a {
  align-items: start;
  color: var(--text);
  display: grid;
  gap: clamp(0.8rem, 2vw, 1.5rem);
  grid-template-columns: 2.5rem minmax(14rem, 0.9fr) minmax(18rem, 1.1fr) 1.5rem;
  padding: clamp(1rem, 2.5vw, 1.5rem) 0.65rem;
  text-decoration: none;
}
.home-case-study-list a:hover,
.home-case-study-list a:focus-visible {
  background: var(--panel);
}
.home-case-study-number {
  color: var(--accent-strong);
  font: 750 0.75rem/1.4 var(--font-ui);
  letter-spacing: 0.08em;
  padding-top: 0.2rem;
}
.home-case-study-list strong {
  font-family: var(--font-serif);
  font-size: clamp(1.2rem, 2vw, 1.55rem);
  font-weight: 550;
  line-height: 1.22;
}
.home-case-study-list small {
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.5;
}
.home-case-study-arrow {
  color: var(--accent-strong);
  font-size: 1.25rem;
  line-height: 1;
  padding-top: 0.1rem;
  text-align: right;
}
.book-shell {
  --book-demo-inline-extension: calc(18rem + clamp(1rem, 3vw, 2rem));
  display: grid;
  gap: clamp(1rem, 3vw, 2rem);
  grid-template-areas: "navigation chapter balance";
  grid-template-columns: 18rem minmax(0, 1fr) 18rem;
  margin: 0 auto;
  max-width: 92rem;
  padding: clamp(2rem, 4vw, 3.5rem) clamp(1rem, 3vw, 2.5rem) 5rem;
}
.book-shell::after {
  content: "";
  grid-area: balance;
}
.book-navigation {
  align-self: start;
  grid-area: navigation;
  max-height: calc(100vh - 6rem);
  overflow: auto;
  position: sticky;
  top: 5rem;
}
.book-navigation-tabs {
  border: 1px solid var(--border);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-bottom: 1rem;
  padding: 0.2rem;
}
.book-navigation-tabs button {
  background: transparent;
  border: 0;
  border-radius: 0;
  color: var(--muted);
  cursor: pointer;
  font: 750 0.72rem/1.2 var(--font-ui);
  padding: 0.5rem 0.65rem;
}
.book-navigation-tabs button[aria-selected="true"] {
  background: var(--accent-strong);
  color: var(--panel);
}
.book-navigation-tabs button:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 42%, transparent);
  outline-offset: 2px;
}
.book-sidebar ol,
.local-toc ol {
  list-style: none;
  margin: 0;
  padding: 0;
}
.book-sidebar-part + .book-sidebar-part {
  margin-top: 1.2rem;
}
.book-sidebar h2 {
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 650;
  line-height: 1.25;
  margin: 0 0 0.2rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.book-sidebar h2 a {
  color: inherit;
  text-decoration-color: var(--accent);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.16em;
}
.book-sidebar h2 a:hover {
  color: var(--accent-strong);
}
.book-sidebar-part > p {
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.35;
  margin: 0 0 0.5rem;
}
.book-sidebar a,
.book-sidebar-disabled {
  align-items: baseline;
  border-radius: 0.35rem;
  color: var(--text);
  display: grid;
  gap: 0.55rem;
  grid-template-columns: 1.6rem 1fr;
  line-height: 1.3;
  padding: 0.45rem 0.55rem;
  text-decoration: none;
}
.book-sidebar-disabled {
  color: var(--muted);
  opacity: 0.68;
}
.book-sidebar a[aria-current="page"] {
  background: var(--panel);
  box-shadow: inset 3px 0 0 var(--accent);
  font-weight: 650;
}
.book-sidebar a span,
.book-sidebar-disabled span {
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 600;
}
.book-sidebar a[aria-current="page"] span:last-child {
  font-weight: 650;
}
.book-sidebar .book-sidebar-part-link {
  grid-column: 1 / -1;
}
.local-toc a {
  color: var(--muted);
  display: block;
  font-size: 0.88rem;
  line-height: 1.35;
  padding: 0.25rem 0;
  position: relative;
  text-decoration: none;
  transition:
    color 0.18s ease,
    transform 0.18s ease;
}
.local-toc a::before {
  background: transparent;
  border-radius: 999px;
  content: "";
  inset: 0 auto 0 -0.55rem;
  position: absolute;
  width: 2px;
}
.local-toc a:hover,
.local-toc a:focus-visible {
  color: var(--text);
}
.local-toc a[aria-current="location"],
.local-toc a.is-current {
  color: var(--text);
  font-weight: 650;
}
.local-toc a[aria-current="location"]::before,
.local-toc a.is-current::before {
  background: var(--accent);
}
.local-toc .toc-level-3 {
  padding-left: 1.35rem;
}
.chapter-main {
  grid-area: chapter;
  min-width: 0;
}
.guide-main {
  margin: 0 auto;
  max-width: 52rem;
  padding: clamp(2rem, 4vw, 3.5rem) clamp(1rem, 3vw, 2.5rem) 5rem;
}
.guide-main > .prose {
  padding: 0;
}
@media (min-width: 76.0625rem) {
  .book-shell[data-layout-ready="true"] {
    transition:
      grid-template-columns 260ms cubic-bezier(0.22, 1, 0.36, 1),
      max-width 260ms cubic-bezier(0.22, 1, 0.36, 1);
  }
  .book-navigation {
    overflow-x: clip;
  }
  .book-navigation details::details-content {
    opacity: 0;
    transition:
      content-visibility 180ms allow-discrete,
      opacity 140ms ease;
  }
  .book-navigation details[open]::details-content {
    opacity: 1;
    transition-delay: 80ms;
  }
  .book-navigation summary {
    align-items: center;
    cursor: pointer;
    display: flex;
    gap: 0.5rem;
    justify-content: space-between;
  }
  .book-navigation summary::after {
    color: var(--accent-strong);
    content: "←";
    font: 700 0.9rem/1 var(--font-mono);
  }
  .book-navigation details:not([open]) summary {
    justify-content: center;
    height: calc(100vh - 6rem);
    margin: 0;
    min-height: 12rem;
    padding: 0;
  }
  .book-navigation details:not([open]) .book-panel-label {
    clip: rect(0 0 0 0);
    clip-path: inset(50%);
    height: 1px;
    overflow: hidden;
    position: absolute;
    white-space: nowrap;
    width: 1px;
  }
  .book-navigation details:not([open]) .book-panel-icon {
    color: var(--accent-strong);
    display: block;
    fill: none;
    height: 1.25rem;
    stroke: currentColor;
    stroke-linecap: round;
    stroke-linejoin: round;
    stroke-width: 1.7;
    width: 1.25rem;
  }
  .book-navigation details:not([open]) summary::after {
    display: none;
  }
  .book-shell[data-navigation-collapsed="true"] {
    --book-demo-inline-extension: 0rem;
    grid-template-columns: 2.5rem minmax(0, 1fr) 2.5rem;
    max-width: 112rem;
  }
  .book-shell[data-navigation-collapsed="true"] .prose > .book-diagram-figure {
    grid-column: 1 / -1;
    inline-size: min(100%, 64rem);
    justify-self: center;
  }
  .book-shell .prose {
    display: grid;
    grid-template-columns:
      minmax(0, 1fr)
      minmax(0, min(42rem, calc(100vw - 48rem)))
      minmax(0, 1fr);
  }
  .book-shell .prose > * {
    grid-column: 2;
    min-width: 0;
  }
  .book-shell
    .prose
    > :is(
      .observability-demo,
      .reflection-package-demo,
      .scaling-demo,
      .orchestration-lab
    ) {
    grid-column: 1 / -1;
  }
}
.demo-gallery-page {
  background:
    linear-gradient(
      color-mix(in srgb, var(--accent-strong) 5%, transparent) 1px,
      transparent 1px
    ),
    linear-gradient(
      90deg,
      color-mix(in srgb, var(--accent-strong) 5%, transparent) 1px,
      transparent 1px
    );
  background-size: 1.75rem 1.75rem;
  margin: 0 auto;
  max-width: 96rem;
  padding: clamp(2rem, 4vw, 3.5rem) clamp(1rem, 3vw, 2.5rem) 5rem;
}
.demo-gallery-prose {
  padding: 0;
}
.demo-gallery-prose h1 {
  font-size: clamp(2.8rem, 6vw, 6.5rem);
  letter-spacing: -0.055em;
  line-height: 0.88;
  margin: 0 0 clamp(1.5rem, 3vw, 2.5rem);
  max-width: 9ch;
  position: relative;
}
.demo-gallery-prose h1::before {
  color: var(--accent-strong);
  content: "INTERACTIVE SYSTEMS LAB";
  display: block;
  font: 800 0.7rem/1.2 var(--font-mono);
  letter-spacing: 0.12em;
  margin-block-end: 0.75rem;
}
.demo-gallery-lede {
  align-items: stretch;
  background: color-mix(in srgb, var(--panel) 94%, var(--accent) 6%);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  display: grid;
  gap: 0;
  grid-template-columns: minmax(0, 1fr) minmax(22rem, 0.65fr);
  margin-bottom: clamp(2rem, 4vw, 3.5rem);
  position: relative;
}
.demo-gallery-lede::before {
  background: var(--accent-strong);
  block-size: 0.2rem;
  content: "";
  inline-size: 5rem;
  inset-block-start: -1px;
  inset-inline-start: -1px;
  position: absolute;
}
.demo-gallery-lede p {
  color: var(--muted);
  font-family: var(--font-ui);
  font-size: clamp(1rem, 0.4vw + 0.95rem, 1.18rem);
  line-height: 1.55;
  margin: 0;
  max-width: 52rem;
  padding: clamp(1.25rem, 2.5vw, 2rem);
}
.demo-gallery-stats {
  border-inline-start: 1px solid var(--border);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 0;
}
.demo-gallery-stats > div {
  align-content: center;
  border-inline-end: 1px solid var(--border);
  display: grid;
  min-width: 0;
  padding: 1rem;
}
.demo-gallery-stats > div:last-child {
  border-inline-end: 0;
}
.demo-gallery-stats dt {
  color: var(--muted);
  font: 800 0.62rem/1.2 var(--font-mono);
  letter-spacing: 0.09em;
  text-transform: uppercase;
}
.demo-gallery-stats dd {
  color: var(--accent-strong);
  font: 800 clamp(0.82rem, 1vw, 1rem) / 1.15 var(--font-mono);
  margin: 0.35rem 0 0;
  overflow: hidden;
  text-overflow: ellipsis;
}
.demo-gallery-item {
  background:
    linear-gradient(
      color-mix(in srgb, var(--accent-strong) 5%, transparent) 1px,
      transparent 1px
    ),
    linear-gradient(
      90deg,
      color-mix(in srgb, var(--accent-strong) 5%, transparent) 1px,
      transparent 1px
    ),
    var(--panel);
  background-size: 1.5rem 1.5rem;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  display: grid;
  gap: 0;
  grid-template-columns: minmax(12rem, 0.25fr) minmax(0, 1fr);
  margin-block: clamp(1.25rem, 2.5vw, 2rem);
  padding: 0;
  position: relative;
}
.demo-gallery-item-header {
  align-self: start;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  border-inline-end: 1px solid var(--border);
  display: grid;
  gap: 1rem;
  min-height: 15rem;
  padding: 1.25rem 1rem;
  position: sticky;
  top: 5rem;
}
.demo-gallery-index {
  color: var(--accent-strong);
  font: 800 clamp(2rem, 3vw, 3.2rem) / 0.9 var(--font-mono);
  letter-spacing: -0.08em;
}
.prose .demo-gallery-item-header p {
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  line-height: 1.2;
  margin: 0 0 0.4rem;
  max-width: none;
  text-transform: uppercase;
}
.demo-gallery-item-header a {
  color: var(--text);
  display: block;
  font-family: var(--font-ui);
  font-size: 0.9rem;
  font-weight: 800;
  line-height: 1.25;
  max-width: 15rem;
  text-decoration-color: color-mix(
    in srgb,
    var(--accent-strong) 55%,
    transparent
  );
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}
.demo-gallery-item-header a:hover,
.demo-gallery-item-header a:focus-visible {
  color: var(--accent-strong);
}
.demo-gallery-status {
  align-items: center;
  align-self: end;
  color: var(--muted);
  display: flex;
  font: 750 0.64rem/1.2 var(--font-mono);
  gap: 0.4rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.demo-gallery-status i {
  background: var(--success);
  border-radius: 50%;
  block-size: 0.5rem;
  box-shadow: 0 0 0.65rem color-mix(in srgb, var(--success) 55%, transparent);
  inline-size: 0.5rem;
}
.demo-gallery-item > :not(.demo-gallery-item-header) {
  grid-column: 2;
  inline-size: 100%;
  justify-self: start;
  margin-top: 0;
  max-inline-size: none;
  min-inline-size: 0;
}
.demo-gallery-jumps {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  margin-block: -1rem 2rem;
}
.demo-gallery-jumps a {
  font: 700 0.95rem/1.5 var(--font-ui);
  text-underline-offset: 0.25em;
}
.demo-gallery-practice {
  margin-block-start: clamp(3rem, 6vw, 5rem);
  scroll-margin-top: 6rem;
}
.demo-gallery-practice-header {
  border-block-start: 3px solid var(--accent-strong);
  padding-block-start: 1.5rem;
}
.prose .demo-gallery-practice-kicker {
  color: var(--accent-strong);
  font: 700 0.75rem/1.5 var(--font-mono);
  letter-spacing: 0.06em;
  margin: 0;
  text-transform: uppercase;
}
.demo-gallery-practice-header h2 {
  margin-block: 0.5rem 1rem;
}
.demo-gallery-practice-header > p:last-child {
  color: var(--muted);
  font: 1rem/1.6 var(--font-ui);
  max-inline-size: 65ch;
}
.demo-gallery-practice-index {
  display: grid;
  gap: 0.75rem;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-block: 1.5rem 2rem;
}
.demo-gallery-practice-index a {
  align-items: center;
  background: var(--panel);
  border: 1px solid var(--border);
  display: flex;
  font: 700 0.95rem/1.4 var(--font-ui);
  gap: 0.75rem;
  padding: 1rem;
  text-underline-offset: 0.2em;
}
.demo-gallery-practice-index span {
  color: var(--muted);
  font: 700 0.85rem/1.4 var(--font-mono);
}
.demo-gallery-practice-item {
  background: var(--panel);
  border: 1px solid var(--border);
  border-inline-start: 3px solid var(--accent);
  margin-block: 1.5rem;
  min-inline-size: 0;
}
.demo-gallery-practice-item .book-exercise {
  border: 0;
  margin: 0;
  min-inline-size: 0;
}
.demo-gallery-practice-item .book-exercise > p:not(.exercise-kicker) {
  font: 1rem/1.65 var(--font-ui);
  max-inline-size: 75ch;
}
.demo-gallery-practice-item .exercise-work:not([hidden]) {
  column-gap: 2rem;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
.demo-gallery-practice-item .exercise-work > :not(.exercise-field) {
  grid-column: 1 / -1;
}
.demo-gallery-practice-item .exercise-field {
  min-inline-size: 0;
}
.prose .demo-gallery-chapter-link {
  border-block-start: 1px solid var(--border);
  font: 700 0.9rem/1.5 var(--font-ui);
  margin: 0;
  padding: 1rem clamp(1.2rem, 3vw, 2rem);
}
@media (max-width: 48rem) {
  .demo-gallery-item > :not(.demo-gallery-item-header) {
    grid-column: 1;
  }
  .demo-gallery-practice-index,
  .demo-gallery-practice-item .exercise-work:not([hidden]) {
    grid-template-columns: 1fr;
  }
}

/* Book prose and chapter navigation */
.prose {
  padding: clamp(1rem, 3vw, 3.5rem) clamp(0.25rem, 2vw, 1.5rem);
}
.prose h1,
.prose h2,
.prose h3,
.prose h4 {
  font-family: var(--font-serif);
  letter-spacing: 0;
  line-height: 1.2;
  position: relative;
}
.prose h1 {
  font-size: clamp(2.35rem, 4.8vw, 4rem);
  font-weight: 500;
  line-height: 1.04;
  margin: 0 0 2.4rem;
  max-width: 14ch;
}
.prose h2 {
  font-size: 2rem;
  margin-top: 2.5rem;
}
.prose h3 {
  font-size: 1.45rem;
  margin-top: 2rem;
}
.prose p,
.prose li {
  font-family: var(--font-serif);
  font-size: clamp(1.05rem, 0.55vw + 0.95rem, 1.22rem);
  line-height: 1.72;
  /* Keep body copy comfortably below WCAG's 80-character line ceiling. */
  max-width: 66ch;
}
.prose p {
  margin: 0 0 1.35em;
}
.prose > ul,
.prose > ol {
  margin-block: 0 1.35em;
}
.prose .chapter-kicker {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  line-height: 1.2;
  max-width: none;
  margin: 0 0 1rem;
}
.prose .chapter-history {
  align-items: center;
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  font: 650 0.72rem/1.4 var(--font-ui);
  gap: 0.45rem 0.7rem;
  letter-spacing: 0.035em;
  margin: -1.45rem 0 2.4rem;
  max-width: 66ch;
}
.prose .chapter-history div {
  align-items: baseline;
  display: flex;
  gap: 0.3rem;
}
.prose .chapter-history div + div::before {
  color: var(--border);
  content: "·";
  margin-right: 0.25rem;
}
.prose .chapter-history dt {
  text-transform: uppercase;
}
.prose .chapter-history dd {
  color: var(--text);
  font-weight: 500;
  margin: 0;
}
.prose img {
  max-width: 100%;
}
.progression-diagram {
  min-width: 58rem;
}
.progression-shared > rect {
  fill: color-mix(in srgb, var(--accent) 11%, var(--panel));
  stroke: color-mix(in srgb, var(--accent-strong) 68%, var(--border));
  stroke-width: 1.5;
}
.progression-kicker {
  fill: var(--accent-strong) !important;
  font-size: 13px;
  font-weight: 850;
  letter-spacing: 1.2px;
}
.progression-shared-title,
.progression-stage-title,
.progression-outcome-title {
  font-size: 20px;
  font-weight: 850;
}
.progression-shared-title {
  font-size: 23px;
}
.progression-detail {
  fill: var(--muted) !important;
  font-size: 15px;
  font-weight: 650;
}
.progression-shared-links path {
  fill: none;
  stroke: var(--border);
  stroke-dasharray: 5 5;
  stroke-width: 1.5;
}
.progression-stage > rect {
  fill: var(--bg);
  stroke: var(--border);
  stroke-width: 1.5;
}
.progression-fresh rect {
  fill: color-mix(in srgb, var(--text) 5%, var(--panel));
  stroke: var(--border);
}
.progression-fresh text {
  fill: var(--muted);
  font-size: 11px;
  font-weight: 850;
  letter-spacing: 0.8px;
}
.progression-learning path {
  fill: none;
  stroke: var(--accent-strong);
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2.5;
}
.progression-learning rect {
  fill: color-mix(in srgb, var(--accent) 14%, var(--panel));
  stroke: var(--accent-strong);
  stroke-width: 1;
}
.progression-learning text {
  fill: var(--accent-strong);
  font-size: 12px;
  font-weight: 850;
  letter-spacing: 0.4px;
}
.progression-outcome > rect {
  fill: color-mix(in srgb, var(--accent) 13%, var(--bg));
  stroke: var(--accent-strong);
  stroke-width: 2;
}
.progression-reset rect {
  fill: color-mix(in srgb, var(--text) 3%, var(--panel));
  stroke: var(--border);
  stroke-dasharray: 5 4;
}
.progression-reset path {
  fill: none;
  stroke: var(--muted);
  stroke-linecap: round;
  stroke-width: 2;
}
.progression-reset text {
  fill: var(--muted);
  font-size: 13px;
  font-weight: 750;
}
.progression-arrow-marker path {
  fill: var(--accent-strong);
}
.progression-shared-arrow-marker path {
  fill: var(--border);
}
.prose blockquote {
  border-left: 0.3rem solid var(--accent);
  color: var(--muted);
  margin-left: 0;
  padding-left: 1rem;
}
.prose pre {
  background: var(--code-bg);
  border-radius: 0.35rem;
  color: var(--code-text);
  overflow: auto;
  padding: 1rem;
}
.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
}
.prose > pre > code.hljs {
  background: transparent;
  color: inherit;
  display: block;
  padding: 0;
}
.prose > pre :is(.hljs-comment, .hljs-quote) {
  color: var(--syntax-comment);
  font-style: italic;
}
.prose > pre :is(.hljs-keyword, .hljs-selector-tag, .hljs-subst) {
  color: var(--syntax-keyword);
}
.prose > pre :is(.hljs-literal, .hljs-number, .hljs-symbol, .hljs-bullet) {
  color: var(--syntax-literal);
}
.prose
  > pre
  :is(
    .hljs-attr,
    .hljs-attribute,
    .hljs-property,
    .hljs-variable,
    .hljs-template-variable
  ) {
  color: var(--syntax-property);
}
.prose > pre :is(.hljs-string, .hljs-doctag, .hljs-regexp) {
  color: var(--syntax-string);
}
.prose
  > pre
  :is(
    .hljs-title,
    .hljs-section,
    .hljs-selector-id,
    .hljs-selector-class,
    .hljs-type,
    .hljs-built_in,
    .hljs-builtin-name,
    .hljs-name
  ) {
  color: var(--syntax-title);
}
.prose
  > pre
  :is(
    .hljs-meta,
    .hljs-meta .hljs-keyword,
    .hljs-selector-attr,
    .hljs-selector-pseudo
  ) {
  color: var(--syntax-meta);
}
.prose > pre .hljs-addition {
  color: var(--syntax-addition);
}
.prose > pre .hljs-deletion {
  color: var(--syntax-deletion);
}
.prose > pre .hljs-emphasis {
  font-style: italic;
}
.prose > pre .hljs-strong {
  font-weight: 700;
}
.prose > pre .hljs-link {
  text-decoration: underline;
  text-underline-offset: 0.14em;
}
:is(.prose > .semantic-table, .project-prose > table) {
  border-collapse: collapse;
  border-spacing: 0;
  font-family: var(--font-ui);
  font-size: clamp(0.82rem, 0.2vw + 0.78rem, 0.92rem);
  inline-size: calc(100% + var(--book-demo-inline-extension, 0rem));
  line-height: 1.48;
  margin-block: 2rem 2.35rem;
  scroll-margin-block-start: 6rem;
}
:is(.prose > .semantic-table, .project-prose > table) th,
:is(.prose > .semantic-table, .project-prose > table) td {
  border-block-end: 1px solid var(--border);
  padding: 0.72rem 0.8rem;
  text-align: start;
  vertical-align: top;
}
:is(.prose > .semantic-table, .project-prose > table) th {
  background: var(--panel);
  color: var(--text);
  font-size: 0.78rem;
  font-weight: 750;
  letter-spacing: 0.025em;
  line-height: 1.35;
}
:is(.prose > .semantic-table, .project-prose > table) tbody tr:nth-child(even) {
  background: color-mix(in srgb, var(--panel) 45%, transparent);
}
:is(.prose > .semantic-table, .project-prose > table) tbody tr:hover {
  background: color-mix(in srgb, var(--accent) 9%, transparent);
}
.prose > :is(.semantic-table, .semantic-figure):target {
  border-radius: 0.2rem;
  outline: 2px solid var(--accent);
  outline-offset: 0.35rem;
}
.semantic-table-caption {
  caption-side: top;
  color: var(--muted);
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.45;
  max-width: 66ch;
  padding-block: 0 0.72rem;
  text-align: start;
}
.semantic-table-number,
.semantic-figure-number {
  color: var(--text);
  font-family: var(--font-ui);
  font-size: 0.8rem;
  font-weight: 750;
  letter-spacing: 0.035em;
  white-space: nowrap;
}
.table-anchor,
.figure-anchor {
  color: var(--muted);
  font-family: var(--font-ui);
  font-size: 0.82em;
  opacity: 0.45;
  text-decoration: none;
  transition:
    color 140ms ease,
    opacity 140ms ease;
}
.table-anchor:hover,
.table-anchor:focus-visible,
.figure-anchor:hover,
.figure-anchor:focus-visible {
  color: var(--accent-strong);
  opacity: 1;
}
@media (max-width: 42rem) {
  .prose > table {
    display: block;
    inline-size: 100%;
    max-inline-size: 100%;
    overflow-x: auto;
    overscroll-behavior-inline: contain;
  }
  :is(.prose > .semantic-table, .project-prose > table) th,
  :is(.prose > .semantic-table, .project-prose > table) td {
    min-inline-size: 10rem;
  }
}
.prose .semantic-citation {
  color: var(--accent-strong);
  text-decoration-color: var(--accent);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.14em;
  white-space: nowrap;
}
.prose .semantic-bibliography {
  margin: 0 0 2rem;
  max-width: 66ch;
  padding-inline-start: 1.6em;
}
.prose .semantic-bibliography li {
  font-size: 0.96em;
  margin-bottom: 0.8em;
  padding-inline-start: 0.35em;
}
.prose .semantic-bibliography a {
  overflow-wrap: anywhere;
}
.prose .semantic-bibliography li:target {
  border-radius: 0.2rem;
  outline: 2px solid var(--accent);
  outline-offset: 0.3rem;
}
.heading-anchor {
  color: var(--muted);
  font-family: var(--font-ui);
  font-size: 0.55em;
  inset-block-start: 0.2em;
  inset-inline-start: calc(100% + 0.35rem);
  opacity: 0;
  position: absolute;
  text-decoration: none;
  transition: opacity 140ms ease;
}
.prose h1:hover .heading-anchor,
.prose h2:hover .heading-anchor,
.prose h3:hover .heading-anchor,
.prose h4:hover .heading-anchor,
.heading-anchor:focus-visible {
  opacity: 0.65;
}
.chapter-pagination {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 1rem;
}
.chapter-pagination a {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  color: var(--text);
  display: block;
  line-height: 1.35;
  padding: 0.8rem;
  text-decoration: none;
}
.chapter-pagination a:last-child {
  text-align: right;
}
.chapter-pagination span {
  color: var(--muted);
  display: block;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
}

/* Static pedagogical figures generated as SVG during the book build. */
.book-diagram-figure {
  inline-size: calc(100% + var(--book-demo-inline-extension, 0rem));
  margin: 2.15rem 0 2.4rem;
  max-width: 64rem;
}

.book-diagram-canvas {
  background:
    linear-gradient(
      color-mix(in srgb, var(--text) 3%, transparent) 1px,
      transparent 1px
    ),
    linear-gradient(
      90deg,
      color-mix(in srgb, var(--text) 3%, transparent) 1px,
      transparent 1px
    ),
    color-mix(in srgb, var(--text) 1.5%, var(--panel));
  background-size: 1.5rem 1.5rem;
  border: 1px solid var(--border);
  border-radius: 0.45rem;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  padding: clamp(0.5rem, 1.2vw, 0.85rem);
}

.book-diagram-canvas:focus-visible {
  outline: 3px solid var(--accent-strong);
  outline-offset: 0.2rem;
}

.book-diagram {
  display: block;
  height: auto;
  width: 100%;
}

.book-diagram text {
  fill: var(--text);
  font-family: var(--font-ui);
}

.book-diagram-kicker {
  fill: var(--accent-strong) !important;
  font-size: 13px;
  font-weight: 850;
  letter-spacing: 1.2px;
}

.book-diagram-title {
  font-size: 20px;
  font-weight: 850;
}

.book-diagram-detail {
  fill: var(--muted) !important;
  font-size: 15px;
  font-weight: 650;
}

.book-diagram-node > rect {
  fill: var(--bg);
  stroke: var(--border);
  stroke-width: 1.5;
}

.book-diagram-marker path {
  fill: var(--accent-strong);
}

.linear-flow-diagram {
  min-width: 62rem;
}

.linear-flow-connectors path,
.linear-flow-feedback path {
  fill: none;
  stroke: var(--accent-strong);
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2.2;
}

.linear-flow-node.is-emphasis > rect {
  fill: color-mix(in srgb, var(--accent) 12%, var(--bg));
  stroke: var(--accent-strong);
  stroke-width: 2;
}

.linear-flow-node.is-danger > rect {
  fill: color-mix(in srgb, #c74c42 10%, var(--bg));
  stroke: color-mix(in srgb, #c74c42 72%, var(--text));
  stroke-width: 2;
}

.linear-flow-feedback rect,
.linear-flow-note rect,
.knowledge-boundary-link-label rect,
.three-loops-return-label rect {
  fill: color-mix(in srgb, var(--accent) 12%, var(--panel));
  stroke: var(--accent-strong);
  stroke-width: 1;
}

.linear-flow-feedback text,
.knowledge-boundary-link-label text,
.three-loops-return-label text {
  fill: var(--accent-strong);
  font-size: 12px;
  font-weight: 850;
  letter-spacing: 0.35px;
}

.linear-flow-note rect {
  fill: color-mix(in srgb, var(--text) 3%, var(--panel));
  stroke: var(--border);
  stroke-dasharray: 5 4;
}

.knowledge-boundary-diagram {
  min-width: 46rem;
}

.knowledge-boundary-source > rect,
.three-loops-shared > rect {
  fill: color-mix(in srgb, var(--accent) 11%, var(--panel));
  stroke: color-mix(in srgb, var(--accent-strong) 68%, var(--border));
  stroke-width: 1.5;
}

.knowledge-boundary-source-title {
  font-size: 23px;
}

.knowledge-boundary-connectors path {
  fill: none;
  stroke: var(--accent-strong);
  stroke-linecap: round;
  stroke-width: 2.2;
}

.knowledge-boundary-link-label rect {
  fill: var(--panel);
}

.knowledge-boundary-link-label text {
  font-size: 11px;
  letter-spacing: 0.7px;
}

.knowledge-boundary-product.is-slideotter > rect {
  fill: color-mix(in srgb, var(--accent) 7%, var(--bg));
}

.knowledge-boundary-product.is-kirjolab > rect {
  fill: color-mix(in srgb, var(--text) 3%, var(--bg));
}

.knowledge-boundary-item-mark {
  fill: var(--accent-strong);
  stroke: none;
}

.three-loops-diagram {
  min-width: 58rem;
}

.three-loops-shared-links path {
  fill: none;
  stroke: var(--border);
  stroke-dasharray: 5 5;
  stroke-width: 1.5;
}

.three-loops-shared-marker path {
  fill: var(--border);
}

.three-loops-connections path {
  fill: none;
  stroke: var(--accent-strong);
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2.3;
}

.three-loops-card.is-application-loop > rect {
  fill: color-mix(in srgb, var(--accent) 7%, var(--bg));
}

.three-loops-card.is-development-loop > rect {
  fill: color-mix(in srgb, var(--text) 3%, var(--bg));
}

.three-loops-card.is-agentic-loop > rect {
  fill: color-mix(in srgb, var(--accent) 12%, var(--bg));
  stroke: var(--accent-strong);
  stroke-width: 2;
}

.three-loops-purpose {
  font-size: 14px;
}

.three-loops-sequence {
  fill: var(--muted) !important;
  font-size: 14px;
  font-weight: 700;
}

.book-diagram-figure figcaption {
  color: var(--muted);
  font-family: var(--font-serif);
  font-size: 0.96rem;
  inline-size: 100%;
  line-height: 1.48;
  margin-block-start: 0.75rem;
  max-width: none;
}

@media print {
  .book-diagram-canvas {
    overflow: visible;
  }

  .book-diagram {
    min-width: 0 !important;
  }
}

/* Feedback threads, paragraph controls, and reflection prompts */
.paragraph-feedback-panel button,
.paragraph-comment-form button {
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  cursor: pointer;
  font: 700 0.78rem/1.15 var(--font-ui);
  min-block-size: 1.85rem;
  padding: 0.3rem 0.55rem;
}
.paragraph-comment-form button:first-child {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
  color: var(--panel);
}
.paragraph-comment-form button:first-child:hover {
  background: var(--accent);
  border-color: var(--accent);
}
.comment-thread {
  border-top: 1px solid var(--border);
  padding-top: 0.85rem;
}
.comment-thread + .comment-thread {
  margin-top: 0.85rem;
}
.comment-thread h3 {
  font: 700 0.82rem/1.3 var(--font-ui);
  letter-spacing: 0.08em;
  margin: 0 0 0.45rem;
  text-transform: uppercase;
}
.comment-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  padding: 0.75rem;
}
.comment-card.is-hidden {
  opacity: 0.68;
}
.comment-card.is-featured {
  background: color-mix(in srgb, var(--accent) 10%, var(--bg));
  border-color: color-mix(in srgb, var(--accent) 55%, var(--border));
}
.comment-card + .comment-card {
  margin-top: 0.5rem;
}
.comment-card p {
  color: var(--text);
  font-size: 0.95rem;
  margin: 0.45rem 0 0;
  white-space: pre-wrap;
}
.comment-meta {
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  font-size: 0.82rem;
}
.comment-meta em {
  color: var(--accent-strong);
  font-style: normal;
  font-weight: 700;
}
.comment-replies {
  border-left: 2px solid var(--border);
  display: grid;
  gap: 0.55rem;
  margin-top: 0.75rem;
  padding-left: 0.75rem;
}
.comment-reply {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  padding: 0.65rem;
}
.comment-reply p {
  margin: 0.35rem 0 0;
}
[data-comment-target] {
  padding-inline-end: 3rem;
  position: relative;
}
.paragraph-feedback-actions {
  display: none;
  inset-inline-end: 0.25rem;
  position: absolute;
  top: 0.1rem;
  transform: translateX(0.2rem);
  transition:
    opacity 140ms ease,
    transform 140ms ease;
  z-index: 1;
}
.paragraph-comment-button {
  align-items: center;
  background: color-mix(in srgb, var(--panel) 82%, transparent);
  border: 1px solid transparent;
  border-radius: 999px;
  color: var(--muted);
  cursor: pointer;
  display: none;
  block-size: 1.55rem;
  inline-size: 1.55rem;
  justify-content: center;
  opacity: 0;
  padding: 0;
  transition:
    background 140ms ease,
    border-color 140ms ease,
    color 140ms ease,
    opacity 140ms ease,
    transform 140ms ease;
}
[data-comments-ready="true"] .paragraph-comment-button,
[data-comments-admin="true"] .paragraph-comment-button,
.paragraph-comment-button.has-comments {
  display: inline-flex;
}
.paragraph-comment-button svg {
  block-size: 0.95rem;
  fill: none;
  inline-size: 0.95rem;
  stroke: currentColor;
  stroke-linejoin: round;
  stroke-width: 1.8;
}
[data-comment-target]:hover .paragraph-comment-button,
.paragraph-comment-button:focus-visible,
.paragraph-comment-button.has-comments {
  border-color: var(--border);
  opacity: 1;
}
[data-comments-ready="true"]
  [data-comment-target]:hover
  .paragraph-feedback-actions,
[data-comments-admin="true"]
  [data-comment-target]:hover
  .paragraph-feedback-actions,
[data-comments-ready="true"]
  [data-comment-target].is-feedback-selected
  .paragraph-feedback-actions,
[data-comments-admin="true"]
  [data-comment-target].is-feedback-selected
  .paragraph-feedback-actions,
.paragraph-feedback-actions:focus-within,
[data-comment-target]:has(.has-comments) .paragraph-feedback-actions {
  display: flex;
  transform: translateX(0);
}
[data-comment-target].is-feedback-source {
  background: color-mix(in srgb, var(--accent) 9%, transparent);
  border-radius: 0.25rem;
  box-shadow:
    inset 3px 0 0 var(--accent),
    0 0 0 1px color-mix(in srgb, var(--accent) 24%, transparent);
  margin-inline: -0.4rem;
  padding-block: 0.18rem;
  padding-inline-start: 0.4rem;
}
[data-comment-target].is-feedback-source::before {
  background: var(--accent);
  block-size: 1rem;
  border-radius: 999px;
  content: "";
  inline-size: 2px;
  inset-block-end: -1rem;
  inset-inline-start: 0.85rem;
  position: absolute;
}
[data-comments-preview="public"] .paragraph-feedback-actions {
  display: none;
}
.paragraph-comment-button.has-comments {
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  border-color: var(--accent);
  color: var(--accent-strong);
}
.paragraph-comment-button.has-comments::after {
  align-items: center;
  background: var(--accent);
  border-radius: 999px;
  color: var(--panel);
  content: attr(data-comment-count);
  display: flex;
  font: 700 0.62rem/1 var(--font-ui);
  inset-block-start: -0.42rem;
  inset-inline-end: -0.42rem;
  justify-content: center;
  min-block-size: 0.9rem;
  min-inline-size: 0.9rem;
  padding: 0 0.16rem;
  position: absolute;
}
@media (max-width: 48rem) {
  [data-comment-target] {
    padding-inline-end: 3rem;
  }
  .paragraph-feedback-actions {
    inset-inline-end: 0;
  }
}
@media (hover: none) {
  [data-comments-ready="true"] .paragraph-feedback-actions,
  [data-comments-admin="true"] .paragraph-feedback-actions {
    display: flex;
    transform: translateX(0);
  }
  [data-comments-ready="true"] .paragraph-comment-button,
  [data-comments-admin="true"] .paragraph-comment-button {
    border-color: color-mix(in srgb, var(--border) 65%, transparent);
    opacity: 0.5;
  }
  [data-comment-target].is-feedback-selected .paragraph-comment-button,
  [data-comment-target].is-feedback-source .paragraph-comment-button,
  .paragraph-comment-button.has-comments {
    opacity: 1;
  }
}
.paragraph-comment-form {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  display: grid;
  gap: 0.6rem;
  margin: 0.75rem 0 1rem;
  max-width: 68ch;
  padding: 0.75rem;
}
.paragraph-feedback-panel {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  display: grid;
  gap: 0.6rem;
  margin: 0.75rem 0 1rem;
  max-width: 68ch;
  padding: 0.75rem;
}
.paragraph-feedback-panel-header {
  align-items: center;
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  justify-content: flex-start;
}
.paragraph-feedback-panel h3 {
  color: var(--muted);
  flex: 1 1 8rem;
  font: 700 0.78rem/1.3 var(--font-ui);
  letter-spacing: 0.08em;
  margin: 0;
  text-transform: uppercase;
}
.paragraph-feedback-panel > p {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0;
}
.paragraph-feedback-context {
  background: color-mix(in srgb, var(--accent) 7%, transparent);
  border-left: 2px solid var(--accent);
  border-radius: 0.25rem;
  display: grid;
  gap: 0.25rem;
  padding: 0.45rem 0.6rem;
}
.paragraph-feedback-context strong {
  color: var(--accent-strong);
  font: 700 0.72rem/1.2 var(--font-ui);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.paragraph-feedback-context p {
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.35;
  margin: 0;
}
.paragraph-feedback-panel button {
  background: var(--panel);
  color: var(--text);
}
.paragraph-feedback-panel-header button {
  flex: 0 0 auto;
}
.paragraph-feedback-panel button:hover {
  border-color: var(--accent);
  color: var(--accent-strong);
}
.paragraph-feedback-card {
  margin-top: 0;
}
.comment-card-actions {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-block-start: 0.55rem;
}
.comment-action-menu {
  display: inline-grid;
  gap: 0.3rem;
  position: relative;
}
.comment-action-menu summary {
  align-items: center;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  cursor: pointer;
  display: inline-flex;
  font: 700 0.78rem/1.15 var(--font-ui);
  min-block-size: 1.85rem;
  padding: 0.3rem 0.55rem;
}
.comment-action-menu summary:hover,
.comment-action-menu[open] summary {
  border-color: var(--accent);
  color: var(--accent-strong);
}
.comment-action-menu[open] {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  box-shadow: var(--shadow);
  padding: 0.3rem;
  z-index: 5;
}
.comment-action-menu[open] summary {
  border-color: transparent;
}
.comment-action-menu[open] button {
  background: transparent;
  border-color: transparent;
  display: block;
  inline-size: 100%;
  text-align: left;
}
@media (min-width: 76rem) {
  .paragraph-comment-form,
  .paragraph-feedback-panel {
    box-shadow: var(--shadow);
    inline-size: min(26rem, calc((100vw - 88rem) / 2 + 14rem));
    margin: 0;
    max-block-size: calc(100vh - var(--comment-form-top, 6rem) - 1rem);
    max-width: none;
    overflow: auto;
    position: fixed;
    inset-block-start: var(--comment-form-top, 6rem);
    inset-inline-end: clamp(1rem, 3vw, 2.5rem);
    z-index: 4;
  }
  .paragraph-comment-form textarea {
    min-height: 9rem;
  }
}
.paragraph-comment-form label {
  color: var(--muted);
  display: grid;
  font-size: 0.88rem;
  font-weight: 700;
  gap: 0.25rem;
}
.paragraph-comment-form .inline-option {
  align-items: center;
  display: flex;
  gap: 0.45rem;
}
.paragraph-comment-form select {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  color: var(--text);
  font: inherit;
  padding: 0.45rem 0.55rem;
}
.paragraph-comment-form textarea {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  color: var(--text);
  font: inherit;
  min-height: 7rem;
  padding: 0.6rem;
  resize: vertical;
  width: 100%;
}
.paragraph-comment-form div {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.reflection-prompts {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
  padding: 0.85rem;
}
.reflection-prompts[hidden] {
  display: none;
}
.reflection-prompts h2 {
  color: var(--muted);
  flex-basis: 100%;
  font: 700 0.78rem/1.3 var(--font-ui);
  letter-spacing: 0.08em;
  margin: 0;
  text-transform: uppercase;
}
.reflection-prompts button {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  color: var(--text);
  cursor: pointer;
  font: inherit;
  font-size: 0.9rem;
  font-weight: 700;
  padding: 0.35rem 0.65rem;
}

/* Local Markdown editor */
.editor-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-left: 0.35rem solid var(--accent);
  border-radius: 0.5rem;
  box-shadow: var(--shadow);
  display: grid;
  gap: 1rem;
  margin-bottom: 1rem;
  padding: 1rem;
}
.editor-panel[hidden] {
  display: none;
}
.editor-panel h2 {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 500;
  line-height: 1.2;
  margin: 0;
}
.editor-panel p {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0.25rem 0 0;
}
.editor-panel textarea {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  color: var(--text);
  font: 0.95rem/1.55 var(--font-mono);
  min-height: 32rem;
  padding: 0.8rem;
  resize: vertical;
  width: 100%;
}
.editor-panel .EasyMDEContainer {
  color: var(--text);
}
.editor-panel .EasyMDEContainer .CodeMirror {
  background: var(--bg);
  border-color: var(--border);
  color: var(--text);
  font: 0.95rem/1.55 var(--font-mono);
}
.editor-panel .EasyMDEContainer .CodeMirror-cursor {
  border-left-color: var(--text);
}
.editor-panel .EasyMDEContainer .CodeMirror-selected {
  background: color-mix(in srgb, var(--accent) 24%, transparent);
}
.editor-panel .editor-toolbar {
  background: var(--panel);
  border-color: var(--border);
  border-radius: 0.35rem 0.35rem 0 0;
}
.editor-panel .editor-toolbar button {
  color: var(--text) !important;
}
.editor-panel .editor-toolbar button:hover,
.editor-panel .editor-toolbar button.active {
  background: var(--bg);
  border-color: var(--border);
}
.editor-panel .editor-toolbar i.separator {
  border-left-color: var(--border);
  border-right-color: transparent;
}
.editor-panel .editor-preview,
.editor-panel .editor-preview-side {
  background: var(--panel);
  color: var(--text);
}
.editor-actions {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.editor-actions button {
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  cursor: pointer;
  font: inherit;
  font-weight: 700;
  padding: 0.45rem 0.75rem;
}
.editor-actions button:first-child {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
  color: var(--panel);
}
.editor-actions button:first-child:hover {
  background: var(--accent);
  border-color: var(--accent);
}
.editor-actions button:last-of-type {
  background: var(--panel);
  color: var(--text);
}
.editor-actions span {
  color: var(--muted);
  font-size: 0.9rem;
}

/* Responsive and motion preferences */
@media (min-width: 68rem) {
  .book-part[aria-labelledby="appendices-heading"] .chapter-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}
@media (max-width: 76rem) {
  .header-actions {
    column-gap: 0.9rem;
  }
  .feedback-controls {
    gap: 0.55rem;
    padding-left: 0.8rem;
  }
  .book-shell {
    --book-demo-inline-extension: 0rem;
    grid-template-areas:
      "navigation"
      "chapter";
    grid-template-columns: minmax(0, 1fr);
  }
  .book-shell::after {
    display: none;
  }
  .book-navigation {
    order: 1;
  }
  .chapter-main {
    order: 2;
  }
  .book-navigation {
    max-height: none;
    position: static;
  }
  .book-navigation {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    padding: 1rem;
  }
  .book-navigation summary {
    align-items: center;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    margin-bottom: 0;
  }
  .book-navigation summary::after {
    color: var(--accent);
    content: "+";
    font-size: 1rem;
    line-height: 1;
  }
  .book-navigation details[open] summary {
    margin-bottom: 0.75rem;
  }
  .book-navigation details[open] summary::after {
    content: "-";
  }
  .book-navigation-tabs {
    display: none;
  }
  .book-navigation-mobile-heading {
    color: var(--muted);
    display: block;
    font: 750 0.72rem/1.2 var(--font-ui);
    letter-spacing: 0.08em;
    margin: 0 0 0.75rem;
    text-transform: uppercase;
  }
  .book-navigation-panel + .book-navigation-panel {
    border-top: 1px solid var(--border);
    margin-top: 1.2rem;
    padding-top: 1.2rem;
  }
  .local-toc ol {
    display: grid;
    gap: 0.2rem;
  }
  .book-sidebar-part ol {
    display: grid;
    gap: 0.35rem 0.75rem;
    grid-template-columns: repeat(auto-fit, minmax(min(18rem, 100%), 1fr));
  }
  .book-sidebar h2 {
    margin-bottom: 0.55rem;
  }
}
@media (max-width: 48rem) {
  body {
    font-size: 16px;
  }
  .site-header {
    gap: 0.35rem;
    grid-template-columns: 1fr;
    padding-block: 0.55rem 0.35rem;
    position: relative;
  }
  .brand {
    font-size: 0.88rem;
    line-height: 2.25rem;
    min-width: 0;
    overflow: hidden;
    padding-right: 3rem;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .site-header[data-learning-ready="true"] .brand {
    line-height: 3rem;
    padding-right: 15.25rem;
  }
  .header-actions {
    align-items: center;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 0.4rem 0.65rem;
    justify-content: stretch;
    position: static;
    width: 100%;
  }
  .site-header nav {
    display: flex;
    flex-wrap: wrap;
    font-size: 0.8rem;
    gap: 0.2rem;
    grid-column: 1 / -1;
    justify-content: space-between;
  }
  .site-header nav a {
    padding: 0.35rem 0.15rem;
    white-space: nowrap;
  }
  .learning-launchers {
    border: 0;
    inset-block-start: 0.55rem;
    inset-inline-end: calc(clamp(1rem, 3vw, 2.5rem) + 3rem);
    padding: 0;
    position: absolute;
  }
  .learning-toggle {
    inline-size: 3.5rem;
  }
  .theme-picker {
    block-size: 2.25rem;
    border: 1px solid var(--border);
    border-radius: 50%;
    display: grid;
    inline-size: 2.25rem;
    inset-block-start: 0.55rem;
    inset-inline-end: clamp(1rem, 3vw, 2.5rem);
    justify-self: auto;
    place-items: center;
    position: absolute;
  }
  .site-header[data-learning-ready="true"] .theme-picker {
    inset-block-start: 0.925rem;
  }
  .theme-picker:focus-within {
    border-color: var(--accent);
    outline: 2px solid var(--accent);
    outline-offset: 2px;
  }
  .theme-picker-icon {
    color: var(--accent);
    inline-size: 1.05rem;
  }
  .theme-picker select {
    block-size: 100%;
    border: 0;
    cursor: pointer;
    inline-size: 100%;
    inset: 0;
    margin: 0;
    max-inline-size: none;
    opacity: 0;
    padding: 0;
    position: absolute;
  }
  .theme-picker select:focus-visible {
    outline: 0;
  }
  .edit-toggle {
    justify-self: start;
    white-space: nowrap;
  }
  .tools-toggle:not([hidden]) {
    display: inline-flex;
    justify-self: start;
  }
  .site-tools-panel {
    display: none;
    gap: 0.75rem;
    grid-column: 1 / -1;
  }
  [data-tools-open="true"] .site-tools-panel {
    display: grid;
  }
  .feedback-controls {
    border-left: 0;
    display: grid;
    flex-basis: auto;
    grid-template-columns: minmax(0, 1fr) auto auto;
    width: 100%;
    padding-left: 0;
  }
  .feedback-controls span {
    grid-column: 1 / -1;
    max-width: none;
  }
  .feedback-controls label {
    min-width: 0;
  }
  .feedback-controls select {
    width: 100%;
  }
  .feedback-controls button,
  .feedback-controls a {
    white-space: nowrap;
  }
  .hero {
    gap: 1.25rem;
    grid-template-columns: 1fr;
    padding-block: 2rem;
  }
  .hero-copy h1 {
    font-size: 2.55rem;
  }
  .project-callout {
    align-items: start;
    grid-template-columns: 1fr;
  }
  .home-case-studies-header {
    align-items: start;
    grid-template-columns: 1fr;
  }
  .home-case-studies-header > a {
    justify-self: start;
  }
  .home-case-study-list a {
    grid-template-columns: 2rem minmax(0, 1fr) 1.25rem;
  }
  .home-case-study-list small {
    grid-column: 2 / -1;
  }
  .cover-panel {
    align-items: stretch;
    grid-template-columns: minmax(5.5rem, 7rem) minmax(0, 1fr);
  }
  .cover-panel img {
    align-self: start;
    border-radius: 0.35rem;
  }
  .course-panel {
    align-self: stretch;
    box-shadow: none;
    display: grid;
    padding: 0.8rem;
  }
  .book-sidebar-part ol {
    grid-template-columns: 1fr;
  }
  .chapter-pagination {
    grid-template-columns: 1fr;
  }
  .chapter-pagination a:last-child {
    text-align: left;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}


.book-exercise {
  scroll-margin-top: 8rem;
  margin: 2.5rem 0;
  padding: clamp(1.2rem, 3vw, 2rem);
  border-block: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  background: var(--panel);
}
.book-exercise .exercise-kicker {
  color: var(--accent-strong);
  font: 0.75rem var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin: 0 0 0.8rem;
}
.book-exercise h3 {
  margin-top: 0;
}
.exercise-field > label {
  display: block;
  margin-block: 1rem 0.5rem;
}
.exercise-field input,
.exercise-field select {
  box-sizing: border-box;
  width: 100%;
  min-height: 2.8rem;
  padding: 0.6rem;
  border: 1px solid var(--muted);
  border-radius: 0;
  background: var(--bg);
  color: var(--text);
  font: 0.95rem var(--font-ui);
}
.exercise-field input {
  max-width: 12rem;
}
.exercise-field [data-feedback] {
  font: 0.9rem/1.5 var(--font-ui);
}
.exercise-result {
  font-weight: 600;
}
.exercise-work .exercise-privacy,
.exercise-work .exercise-status {
  font: 0.85rem/1.5 var(--font-ui);
  color: var(--muted);
}
.exercise-work .exercise-completion {
  font: 0.9rem/1.5 var(--font-ui);
}
.exercise-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin-top: 1rem;
}
.exercise-actions button {
  padding: 0.65rem 1rem;
  background: var(--accent-strong);
  color: var(--panel);
  border: 1px solid var(--accent-strong);
  font: 600 0.9rem var(--font-ui);
  cursor: pointer;
}
.exercise-actions button:disabled {
  opacity: 0.55;
  cursor: default;
}
.book-exercise :focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}
.exercise-discussion {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}
.book-exercise summary {
  cursor: pointer;
}
.exercise-old-answer {
  white-space: pre-wrap;
}
[data-assistant-preview] {
  margin-top: 1rem;
  font: 0.85rem/1.5 var(--font-ui);
}
[data-assistant-preview] pre {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  max-height: 20rem;
  overflow: auto;
}
@media print {
  .exercise-actions,
  .exercise-status,
  .exercise-privacy,
  .exercise-completion {
    display: none;
  }
}

.exercise-tabs {
  margin-block: 2.5rem;
  scroll-margin-top: 8rem;
  /* Exercise controls extend into the grid's balance column, like demos. */
  position: relative;
}
.exercise-tab-list {
  display: flex;
  border-bottom: 1px solid var(--border);
  gap: 0.25rem;
}
.exercise-tab-list button {
  padding: 0.85rem 1rem;
  border: 0;
  border-bottom: 3px solid transparent;
  background: transparent;
  color: var(--muted);
  font: 600 0.9rem var(--font-ui);
  cursor: pointer;
}
.exercise-tab-list button[aria-selected="true"] {
  border-bottom-color: var(--accent);
  background: var(--panel);
  color: var(--text);
}
.exercise-tabs :focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}
.exercise-tab-panel > .book-exercise,
.exercise-tab-panel > section {
  margin-block: 0;
}
.exercise-tab-panel {
  scroll-margin-top: 8rem;
}
@media print {
  .exercise-tab-list {
    display: none;
  }
  .exercise-tabs .exercise-tab-panel[hidden] {
    display: block !important;
  }
}

/* Compact reading aids, using the book's paper, type, and margin rhythm. */
.concept-index {
  border-block: 1px solid var(--border);
  margin-block: 1.6rem 2rem;
  padding-block: 1rem;
}
.concept-index .concept-index-label {
  color: var(--accent-strong);
  font: 750 0.75rem/1.4 var(--font-ui);
  letter-spacing: 0.08em;
  margin: 0 0 0.45rem;
  text-transform: uppercase;
}
.concept-index p:not(.concept-index-label) {
  color: var(--muted);
  font: 0.9rem/1.6 var(--font-ui);
  margin: 0 0 0.8rem;
}
.concept-index ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.1rem;
  list-style: none;
  margin: 0 0 0.8rem;
  padding: 0;
}
.concept-index li {
  font: 600 0.9rem/1.5 var(--font-ui);
}
.concept-index a {
  display: inline-block;
  padding-block: 0.25rem;
  text-underline-offset: 0.2em;
}
.concept-reference-link {
  font: 0.82rem/1.5 var(--font-ui);
}
.concept-link {
  text-decoration-style: dotted;
  text-underline-offset: 0.2em;
}
.concept-reference {
  margin-inline: auto;
  max-width: 76rem;
  padding: clamp(1rem, 4vw, 3rem);
}
.concept-reference [hidden] {
  display: none;
}
.concept-reference-header {
  margin-bottom: 2rem;
}
.concept-reference h1 {
  font: 500 clamp(2.5rem, 5vw, 4rem)/1.1 var(--font-serif);
  margin: 0.7rem 0 1rem;
}
.concept-reference-header > p:not(.eyebrow) {
  font: 1.1rem/1.7 var(--font-serif);
}
.concept-reference-notes {
  color: var(--muted);
  font: 0.85rem/1.6 var(--font-ui);
  max-width: 46rem;
}
.concept-reference-notes > summary {
  cursor: pointer;
  padding-block: 0.4rem;
}
.concept-reference-notes p {
  margin-block: 0.6rem;
}
.concept-lookup {
  max-width: 35rem;
  margin-block: 1.5rem 2rem;
  font: 600 0.85rem/1.5 var(--font-ui);
}
.concept-lookup > label {
  display: block;
  margin-bottom: 0.5rem;
}
.concept-lookup > div {
  display: flex;
  gap: 0.5rem;
}
.concept-lookup input {
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  flex: 1;
  font: 400 1rem/1.5 var(--font-ui);
  min-width: 0;
  padding: 0.75rem;
}
.concept-lookup button {
  background: var(--accent-strong);
  border: 1px solid var(--accent-strong);
  color: var(--panel);
  cursor: pointer;
  font: inherit;
  padding: 0.75rem 1.1rem;
}
.concept-agent {
  background: var(--panel);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-strong);
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 1.5rem 2.5rem;
  padding: clamp(1.25rem, 3vw, 2rem);
}
.concept-agent h2 {
  font: 500 1.75rem/1.3 var(--font-serif);
  margin: 0 0 0.8rem;
}
.concept-agent-introduction > p:last-child {
  color: var(--muted);
  font: 1rem/1.65 var(--font-serif);
  margin: 0;
}
.concept-agent-access {
  align-self: center;
  min-width: 0;
}
.concept-agent-access > label {
  display: block;
  font: 650 0.85rem/1.5 var(--font-ui);
  margin-bottom: 0.6rem;
}
.concept-agent-copy {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.concept-agent-copy input {
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  flex: 1 1 15rem;
  font: 400 0.8rem/1.5 var(--font-ui);
  min-width: 0;
  padding: 0.7rem;
}
.concept-agent-copy button {
  background: var(--panel);
  border: 1px solid var(--accent-strong);
  color: var(--accent-strong);
  cursor: pointer;
  font: 650 0.8rem/1.5 var(--font-ui);
  padding: 0.65rem 1rem;
}
.concept-agent-status {
  color: var(--muted);
  font: 0.8rem/1.5 var(--font-ui);
  margin: 0.5rem 0;
}
.concept-agent-status:empty {
  display: none;
}
.concept-agent-files {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  font: 600 0.8rem/1.5 var(--font-ui);
  margin: 0.8rem 0 0;
}
.concept-agent-setup {
  border-top: 1px solid var(--border);
  grid-column: 1 / -1;
  font: 0.85rem/1.65 var(--font-ui);
  padding-top: 0.75rem;
}
.concept-agent-setup summary {
  cursor: pointer;
  font-weight: 600;
  padding-block: 0.25rem;
}
.concept-agent-setup ol {
  max-width: 54rem;
  padding-left: 1.25rem;
}
.concept-agent-setup li + li {
  margin-top: 0.65rem;
}
.concept-agent-setup > p {
  color: var(--muted);
  margin-bottom: 0;
}
.concept-explorer {
  border-block: 1px solid var(--border);
  margin-block: 2rem;
  scroll-margin-top: 7rem;
}
.concept-explorer > summary {
  cursor: pointer;
  font: 650 1rem/1.5 var(--font-ui);
  padding-block: 1.25rem;
}
.concept-explorer > summary::marker {
  color: var(--accent-strong);
}
.concept-explorer-description {
  color: var(--muted);
  font: 400 0.8rem/1.5 var(--font-ui);
  margin-left: 1rem;
}
.concept-exploration-context {
  margin-block: 1.5rem 2rem;
}
.concept-exploration-heading {
  align-items: baseline;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: space-between;
}
.concept-exploration-heading h2 {
  font: 500 2rem/1.25 var(--font-serif);
  max-width: 46rem;
  margin: 0;
  scroll-margin-top: 7rem;
}
.concept-context-label {
  color: var(--accent-strong);
  font: 650 0.75rem/1.5 var(--font-ui);
  letter-spacing: 0.06em;
  margin: 0 0 0.5rem;
  text-transform: uppercase;
}
.concept-exploration-heading button {
  background: transparent;
  border: 0;
  color: var(--accent-strong);
  cursor: pointer;
  font: 600 0.8rem/1.5 var(--font-ui);
  padding: 0.3rem 0;
  text-decoration: underline;
  text-underline-offset: 0.2em;
}
.concept-exploration-context > p {
  font: 1.1rem/1.7 var(--font-serif);
  max-width: 52rem;
}
.concept-exploration-context > .concept-prediction {
  background: var(--panel);
  border-left: 2px solid var(--accent-strong);
  font: 0.95rem/1.7 var(--font-ui);
  padding: 1rem 1.2rem;
}
.concept-exploration-context > a {
  font: 600 0.85rem/1.5 var(--font-ui);
}
.concept-map-tools > summary {
  cursor: pointer;
  font: 600 0.8rem/1.5 var(--font-ui);
  padding-top: 0.75rem;
}
.concept-lookup input:focus-visible,
.concept-lookup button:focus-visible,
.concept-agent a:focus-visible,
.concept-agent-copy input:focus-visible,
.concept-agent-copy button:focus-visible,
.concept-agent-setup summary:focus-visible,
.concept-explorer > summary:focus-visible,
.concept-exploration-heading h2:focus-visible,
.concept-exploration-heading button:focus-visible,
.concept-exploration-context > a:focus-visible,
.concept-map-tools > summary:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 4px;
}
.concept-card {
  border-bottom: 1px solid var(--border);
  padding-block: 0 2rem;
  margin-bottom: 2rem;
  scroll-margin-top: 7rem;
}
.concept-card h2 {
  font: 500 2rem/1.2 var(--font-serif);
  margin: 0 0 1.5rem;
}
.concept-card h3 {
  font: 700 0.9rem/1.5 var(--font-ui);
  margin: 1.5rem 0 0.55rem;
}
.concept-passages {
  margin: 0;
}
.concept-passages > div + div {
  margin-top: 1.2rem;
}
.concept-passages dt {
  color: var(--muted);
  font: 700 0.72rem/1.5 var(--font-ui);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 0.3rem;
}
.concept-passages dd {
  font: 1.08rem/1.7 var(--font-serif);
  margin: 0;
}
.concept-contexts,
.concept-relationships {
  font: 0.9rem/1.65 var(--font-ui);
  padding-left: 1.15rem;
  margin: 0;
}
.concept-contexts li + li,
.concept-relationships li + li {
  margin-top: 0.6rem;
}
.concept-contexts p {
  color: var(--muted);
  font: 0.85rem/1.5 var(--font-ui);
  margin: 0.2rem 0 0;
}
.concept-relationships p {
  color: var(--muted);
  font: 0.85rem/1.5 var(--font-ui);
  margin: 0.2rem 0 0;
}
.concept-map-disclosure {
  margin-block: 0.7rem 1rem;
}
.concept-map-disclosure > summary,
.concept-map-relationships > summary {
  cursor: pointer;
  font: 600 0.85rem/1.6 var(--font-ui);
  padding-block: 0.5rem;
}
.concept-map {
  border: 1px solid var(--border);
  background: var(--bg);
  margin-block: 1rem 1.5rem;
  padding: 1rem;
}
.concept-map-heading {
  align-items: baseline;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1rem;
  justify-content: space-between;
}
.concept-map .concept-map-heading h2 {
  font: 700 1rem/1.5 var(--font-ui);
  margin: 0;
}
.concept-map-heading label {
  font: 0.8rem/1.5 var(--font-ui);
}
.concept-map-heading-actions {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
}
/* Preserve the header's layout while removing the graph-only action from use. */
.concept-map-complete.is-list-view [data-concept-expand][hidden] {
  display: block;
  visibility: hidden;
}
.concept-view-switch {
  border: 1px solid var(--border);
  border-radius: 0.25rem;
  display: flex;
  overflow: hidden;
}
.concept-map-heading-actions .concept-view-switch button {
  border: 0;
}
.concept-map-heading-actions .concept-view-switch button + button {
  border-left: 1px solid var(--border);
}
.concept-map-heading-actions .concept-view-switch [aria-selected="true"] {
  background: var(--accent-strong);
  color: var(--panel);
}
.concept-map-heading-actions .concept-view-switch button:focus-visible {
  outline-offset: -3px;
}
.concept-map-heading-actions
  .concept-view-switch
  [aria-selected="true"]:focus-visible {
  outline-color: var(--panel);
}
.concept-map-complete.is-list-view {
  width: auto;
  margin-inline: 0;
}
.concept-map-heading-actions a {
  font: 0.75rem/1.5 var(--font-ui);
}
.concept-map select {
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  font: inherit;
  max-width: 100%;
  padding: 0.4rem;
}
.concept-map > p,
.concept-map .concept-map-relationships li {
  font: 0.85rem/1.6 var(--font-ui);
  margin: 0.6rem 0;
}
.concept-map-graphic svg {
  width: 100%;
  height: auto;
  display: block;
}
.concept-map-graphic line {
  stroke: var(--muted);
  stroke-width: 1.5;
}
.concept-map-graphic [data-concept-arrow] {
  fill: var(--muted);
  stroke: none;
}
.concept-map-graphic .is-related [data-concept-arrow],
.concept-map-graphic .is-group-edge [data-concept-arrow],
.concept-map-graphic .is-group-bridge [data-concept-arrow],
.concept-map-graphic .is-previewed [data-concept-arrow] {
  fill: var(--accent-strong);
}
.concept-map-graphic rect {
  fill: var(--panel);
  stroke: var(--accent-strong);
  stroke-width: 1.5;
}
.concept-map-graphic text {
  fill: var(--text);
  font: 600 17px var(--font-ui);
}
.concept-map-graphic .is-related line {
  stroke: var(--accent-strong);
  stroke-width: 2.5;
}
.concept-map-graphic .is-hidden {
  display: none;
}
.concept-map-graphic a:hover rect,
.concept-map-graphic a:focus-visible rect {
  stroke: var(--accent-strong);
  stroke-width: 3;
}
.concept-map-graphic .is-current rect {
  fill: var(--accent-strong);
  stroke-width: 3;
}
.concept-map-graphic .is-current text {
  fill: var(--panel);
}
.concept-map-graphic .is-group-member rect {
  fill: var(--accent-strong);
  stroke-width: 3;
}
.concept-map-graphic .is-group-member text {
  fill: var(--panel);
}
.concept-map-graphic .is-group-member:hover rect,
.concept-map-graphic .is-group-member:focus-visible rect {
  stroke: var(--text);
  stroke-width: 4;
}
.concept-map-graphic .is-group-member:focus-visible rect {
  stroke-dasharray: 5 3;
}
.concept-map-graphic .is-group-context rect {
  stroke: var(--muted);
}
.concept-map-graphic .is-group-context:hover rect,
.concept-map-graphic .is-group-context:focus-visible rect {
  stroke: var(--accent-strong);
}
.concept-map-graphic .is-selected rect {
  fill: var(--accent-strong);
  stroke: var(--text);
  stroke-width: 3;
}
.concept-map-graphic .is-selected text {
  fill: var(--panel);
}
.is-highlighting-group .concept-map-graphic [data-concept-edge] line {
  opacity: 0.16;
}
.is-highlighting-group .concept-map-graphic [data-concept-arrow] {
  opacity: 0.16;
}
.is-highlighting-group
  .concept-map-graphic
  .is-group-edge
  [data-concept-arrow] {
  opacity: 1;
}
.is-highlighting-group
  .concept-map-graphic
  .is-group-bridge
  [data-concept-arrow] {
  opacity: 0.85;
}
.is-highlighting-group .concept-map-graphic .is-group-edge line {
  stroke: var(--accent-strong);
  stroke-width: 3;
  opacity: 1;
}
.is-highlighting-group .concept-map-graphic .is-group-bridge line {
  stroke: var(--accent-strong);
  stroke-width: 2.5;
  stroke-dasharray: 6 4;
  opacity: 0.85;
}
.is-highlighting-group
  .concept-map-graphic
  .concept-edge-label.is-group-edge
  rect,
.is-highlighting-group
  .concept-map-graphic
  .concept-edge-label.is-group-bridge
  rect {
  stroke: var(--accent-strong);
  stroke-width: 1;
}
.concept-map-relationships ul {
  padding-left: 1.2rem;
}
.concept-map .concept-map-status {
  color: var(--muted);
  font-size: 0.75rem;
}
.concept-pane .concept-map {
  margin-block: 1.4rem;
}
.concept-pane .concept-map h2 {
  font: 700 0.9rem/1.5 var(--font-ui);
}
.concept-map-graphic .concept-edge-label {
  display: none;
  pointer-events: none;
}
.concept-map.has-connection-labels .concept-edge-label:not(.is-hidden),
.concept-map .concept-edge-label.is-previewed:not(.is-hidden) {
  display: block;
}
.concept-map-graphic .concept-edge-label rect {
  fill: var(--bg);
  stroke: var(--border);
  stroke-width: 0.5;
}
.concept-map-graphic .concept-edge-label text {
  fill: var(--text);
  font: 600 12px var(--font-ui);
}
.concept-map-graphic .concept-edge-label line {
  stroke: var(--muted);
  stroke-width: 1;
}
.concept-map .concept-map-legend {
  color: var(--muted);
  font-size: 0.75rem;
}
.concept-connection-practice {
  border-top: 1px solid var(--border);
  margin-top: 0.5rem;
  font: 0.85rem/1.6 var(--font-ui);
}
.concept-connection-practice > summary {
  cursor: pointer;
  font-weight: 600;
  padding-block: 0.5rem;
}
.concept-connection-practice > p {
  max-width: 42rem;
  margin-block: 0.25rem 0.75rem;
}
.concept-connection-practice > summary:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 3px;
}
.concept-relationship-label {
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 0.2rem;
  display: inline-block;
  font: 600 0.7rem/1.4 var(--font-ui);
  padding: 0.15rem 0.4rem;
}
.concept-map-disclosure summary:focus-visible,
.concept-map-relationships summary:focus-visible,
.concept-map select:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 3px;
}
.concept-pane {
  background: var(--panel);
  border: 0;
  border-left: 1px solid var(--border);
  color: var(--text);
  box-shadow: var(--shadow);
  width: min(38rem, 100%);
  height: 100vh;
  height: 100dvh;
  max-width: 100%;
  max-height: 100%;
  margin: 0 0 0 auto;
  padding: 0;
  inset: 0;
  overscroll-behavior: contain;
}
.concept-pane::backdrop {
  background: rgb(0 0 0 / 24%);
}
.concept-pane-header {
  align-items: center;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.8rem 1.5rem;
  position: sticky;
  top: 0;
  z-index: 1;
  font: 600 0.8rem/1.5 var(--font-ui);
}
.concept-pane-header button {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  cursor: pointer;
  font: inherit;
  padding: 0.5rem 0.75rem;
}
.concept-pane-content {
  padding: 1.75rem clamp(1rem, 4vw, 2rem) 0;
}
.concept-pane .concept-card {
  border: 0;
  margin-bottom: 0;
  padding-bottom: 1rem;
}
.concept-pane footer {
  border-top: 1px solid var(--border);
  font: 0.85rem/1.5 var(--font-ui);
  padding: 1rem clamp(1rem, 4vw, 2rem);
}
.concept-index a:focus-visible,
.concept-card a:focus-visible,
.concept-pane button:focus-visible,
.concept-pane h2:focus-visible,
.concept-pane footer a:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 4px;
}
@media (max-width: 480px) {
  .concept-map {
    padding: 0.7rem;
  }
}
@media print {
  body {
    overflow: visible !important;
  }
  .concept-pane {
    display: none !important;
  }
}

.concept-connection-prompt {
  border-left: 2px solid var(--accent-strong);
  padding-left: 0.8rem;
}
.concept-card-group {
  color: var(--muted);
  font: 600 0.75rem/1.5 var(--font-ui);
  margin: 0 0 0.5rem;
}
.concept-directory {
  margin-top: 2.5rem;
  scroll-margin-top: 7rem;
}
.concept-directory[role="tabpanel"] {
  margin-top: 1rem;
}
.concept-directory-heading {
  align-items: baseline;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: space-between;
}
.concept-directory-heading h2 {
  font: 500 2rem/1.2 var(--font-serif);
  margin: 0;
}
.concept-directory-heading p {
  color: var(--muted);
  font: 0.8rem/1.5 var(--font-ui);
  margin: 0.4rem 0 0;
}
.concept-directory-help,
.concept-directory-empty {
  color: var(--muted);
  font: 0.9rem/1.6 var(--font-ui);
  margin-block: 0.8rem 1.5rem;
}
.concept-directory-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}
.concept-directory-list > li {
  min-width: 0;
}
.concept-directory-item {
  background: var(--panel);
  border: 1px solid var(--border);
  height: 100%;
}
.concept-directory-item > summary {
  cursor: pointer;
  display: grid;
  gap: 0.75rem;
  height: 100%;
  list-style: none;
  padding: 1.25rem;
}
.concept-directory-item > summary::-webkit-details-marker {
  display: none;
}
.concept-directory-item > summary:hover {
  background: var(--bg);
}
.concept-summary-heading {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0.3rem 0.75rem;
  justify-content: space-between;
}
.concept-summary-title {
  font: 500 1.35rem/1.3 var(--font-serif);
}
.concept-summary-group {
  color: var(--muted);
  font: 600 0.7rem/1.5 var(--font-ui);
}
.concept-summary-description {
  color: var(--muted);
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  font: 0.9rem/1.6 var(--font-ui);
}
.concept-summary-action {
  color: var(--accent-strong);
  font: 650 0.75rem/1.5 var(--font-ui);
  align-self: end;
}
.concept-directory-list > .is-group-member .concept-directory-item {
  border-color: var(--accent-strong);
}
.concept-directory-list > li:has(> details[open]) {
  grid-column: 1 / -1;
}
.concept-directory-item[open] > summary {
  border-bottom: 1px solid var(--border);
  height: auto;
}
.concept-directory-item[open] .concept-summary-description {
  display: block;
}
.concept-directory-item > .concept-card {
  border: 0;
  margin: 0;
  padding: 1.5rem;
}
.concept-neighborhood summary,
.concept-learning-resources summary,
.concept-reading-locations summary {
  cursor: pointer;
  font: 600 0.85rem/1.6 var(--font-ui);
  padding-block: 0.5rem;
}
.concept-neighborhood {
  margin-block: 1rem;
}
.concept-reading-locations {
  margin-top: 1rem;
  font: 0.85rem/1.6 var(--font-ui);
}
.concept-learning-resources {
  border-block: 1px solid var(--border);
  margin-block: 1rem;
  font: 0.85rem/1.6 var(--font-ui);
}
.concept-learning-resources ul {
  padding-left: 1.2rem;
}
.concept-learning-resources li + li {
  margin-top: 1rem;
}
.concept-learning-resources p {
  margin-block: 0.35rem;
}
.concept-map-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  gap: 0.8rem;
  margin-top: 1rem;
}
.concept-map-controls label {
  display: grid;
  gap: 0.35rem;
  font: 600 0.75rem/1.4 var(--font-ui);
  flex: 1 1 10rem;
  min-width: 0;
}
.concept-map-controls select,
.concept-map-controls input {
  width: 100%;
  min-width: 0;
  box-sizing: border-box;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  padding: 0.55rem;
  font: 400 0.85rem/1.5 var(--font-ui);
}
.concept-map-controls input[type="search"] {
  scroll-margin-top: 7rem;
}
.concept-map-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.concept-map-controls .concept-map-label-toggle {
  display: flex;
  align-items: center;
  flex: 1 1 100%;
  gap: 0.5rem;
  font-size: 0.85rem;
}
.concept-map-controls input[type="checkbox"] {
  width: 1rem;
  height: 1rem;
  padding: 0;
  accent-color: var(--accent-strong);
}
.concept-map-group-controls {
  display: flex;
  flex: 1 1 100%;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.9rem 1.2rem;
  border-top: 1px solid var(--border);
  padding-top: 1rem;
}
.concept-map-group-controls > label {
  flex: 0 1 12rem;
}
.concept-group-view {
  border: 0;
  margin: 0;
  padding: 0;
  min-width: 0;
}
.concept-group-view legend {
  font: 600 0.75rem/1.4 var(--font-ui);
  margin-bottom: 0.35rem;
  padding: 0;
}
.concept-group-view > div {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 0.25rem;
  overflow: hidden;
}
.concept-map-controls .concept-group-view label {
  position: relative;
  flex: 0 0 auto;
  display: block;
  font: 600 0.85rem/1.5 var(--font-ui);
  cursor: pointer;
}
.concept-group-view label + label {
  border-left: 1px solid var(--border);
}
.concept-map-controls .concept-group-view input {
  position: absolute;
  inset: 0;
  opacity: 0;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  cursor: pointer;
  z-index: 1;
}
.concept-group-view span {
  display: block;
  background: var(--panel);
  color: var(--text);
  padding: 0.55rem 0.8rem;
}
.concept-group-view input:checked + span {
  background: var(--accent-strong);
  color: var(--panel);
}
.concept-group-view input:focus-visible + span {
  outline: 2px solid currentColor;
  outline-offset: -4px;
}
.concept-map-controls .concept-group-view:disabled label {
  cursor: default;
}
.concept-group-view:disabled input {
  cursor: default;
}
.concept-group-view:disabled span,
.concept-group-view:disabled input:checked + span {
  background: var(--bg);
  color: var(--muted);
}
.concept-map-controls .concept-group-help {
  color: var(--muted);
  flex: 1 1 18rem;
  margin: 0;
  font: 400 0.8rem/1.6 var(--font-ui);
}
.concept-map-actions button,
.concept-map-navigation button,
.concept-map-heading-actions button,
.concept-connection-practice button {
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  cursor: pointer;
  padding: 0.55rem 0.8rem;
  font: 600 0.85rem/1.5 var(--font-ui);
}
.concept-map-complete .concept-map-graphic {
  overflow: auto;
  height: min(65vh, 38rem);
  border-block: 1px solid var(--border);
  margin-top: 1rem;
  background-color: var(--bg);
  background-image: radial-gradient(var(--border) 0.7px, transparent 0.7px);
  background-size: 18px 18px;
  cursor: grab;
  overscroll-behavior: contain;
}
.concept-map-canvas {
  display: grid;
  margin-top: 1rem;
}
.concept-map-canvas > .concept-map-graphic,
.concept-map-navigation {
  grid-area: 1 / 1;
}
.concept-map-complete .concept-map-canvas > .concept-map-graphic {
  margin-top: 0;
}
.concept-map-navigation {
  align-items: center;
  align-self: start;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  display: flex;
  gap: 0.25rem;
  justify-self: end;
  margin: 0.5rem;
  padding: 0.25rem;
  position: sticky;
  top: 5rem;
  z-index: 2;
}
.concept-map-navigation span {
  color: var(--muted);
  font: 600 0.75rem/1.4 var(--font-ui);
  padding-inline: 0.4rem;
  min-width: 3ch;
}
.concept-map-complete .concept-map-graphic.is-interactive {
  overflow: hidden;
  touch-action: none;
  user-select: none;
}
.concept-map-complete .concept-map-graphic.is-interactive svg {
  width: 100%;
  height: 100%;
  margin: 0;
}
.concept-map-complete.is-expanded:not(.is-list-view) {
  --concept-graph-gutter: clamp(1rem, 2vw, 3rem);
  box-sizing: border-box;
  width: calc(100vw - 2 * var(--concept-graph-gutter));
  margin-inline: calc(50% - 50vw + var(--concept-graph-gutter));
}
.concept-map-complete.is-expanded .concept-map-graphic {
  height: max(32rem, 78vh);
}
.concept-map-complete .concept-map-graphic.is-dragging {
  cursor: grabbing;
  user-select: none;
}
.concept-map-complete .concept-map-graphic svg {
  width: max(100%, 1000px);
  max-width: none;
  margin-inline: auto;
}
.concept-map-complete .concept-map-graphic a {
  cursor: pointer;
}
.concept-map-complete .concept-map-graphic line {
  opacity: 0.35;
}
.concept-map-complete .concept-map-graphic .is-related line {
  opacity: 0.8;
}
.concept-map .concept-map-graphic [data-concept-edge].is-previewed line {
  stroke: var(--accent-strong);
  stroke-width: 2.5;
  opacity: 1;
}
.concept-map .concept-map-graphic .is-previewed [data-concept-arrow] {
  opacity: 1;
}
.concept-map .concept-map-help {
  font-size: 0.75rem;
  color: var(--muted);
}
.concept-directory [hidden],
.concept-map-controls .concept-map-label-toggle[hidden],
.concept-map-controls[hidden] {
  display: none;
}
.concept-group-tag {
  border: 1px solid var(--accent-strong);
  border-radius: 0.2rem;
  color: var(--text);
  display: inline-block;
  font: 600 0.65rem/1.4 var(--font-ui);
  margin-left: 0.35rem;
  padding: 0.1rem 0.3rem;
}
.concept-map-relationships strong {
  font-weight: 600;
}
.concept-map-relationships li > p {
  margin: 0.3rem 0 0.9rem;
}
.concept-map button:focus-visible,
.concept-map input:focus-visible,
.concept-map-graphic:focus-visible,
.concept-directory a:focus-visible,
.concept-directory summary:focus-visible,
.concept-reference-notes summary:focus-visible,
.concept-neighborhood summary:focus-visible,
.concept-learning-resources summary:focus-visible,
.concept-reading-locations summary:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 3px;
}
@media (max-width: 760px) {
  .concept-agent {
    grid-template-columns: minmax(0, 1fr);
    gap: 1.25rem;
  }
  .concept-explorer-description {
    display: block;
    margin: 0.35rem 0 0 1rem;
  }
  .concept-map-group-controls > label {
    flex: 1 1 100%;
  }
  .concept-directory-list {
    grid-template-columns: minmax(0, 1fr);
  }
  .concept-directory-item > summary {
    padding: 1rem;
  }
  .concept-directory-item > .concept-card {
    padding: 1.25rem 1rem;
  }
  .concept-summary-description {
    -webkit-line-clamp: 3;
  }
  .concept-map-complete .concept-map-graphic {
    height: 28rem;
  }
}
@media print {
  .concept-map-controls,
  .concept-map-navigation,
  .concept-view-switch,
  .concept-map-heading-actions button,
  .concept-map-help {
    display: none;
  }
  .concept-map-complete.is-expanded {
    width: auto;
    margin-inline: 0;
  }
  .concept-map-complete .concept-map-graphic,
  .concept-map-complete.is-expanded .concept-map-graphic {
    height: auto;
    overflow: visible;
  }
  .concept-map-complete .concept-map-graphic svg {
    width: 100% !important;
    height: auto !important;
  }
  .concept-directory-list {
    display: block;
  }
  .concept-directory-item {
    margin-bottom: 1rem;
  }
}

/* One question to enter, with depth available when the learner chooses it. */
.exploration-page {
  margin-inline: auto;
  max-width: 66rem;
  padding: clamp(1.25rem, 4vw, 3rem);
}
.exploration-header {
  max-width: 48rem;
  margin-block: 1.5rem 2rem;
}
.exploration-header h1 {
  font: 500 clamp(2.25rem, 5vw, 3.6rem)/1.15 var(--font-serif);
  margin-block: 0.6rem 1rem;
  text-wrap: balance;
}
.exploration-header > p:not(.eyebrow) {
  font: 1.15rem/1.7 var(--font-serif);
}
.exploration-start {
  background: var(--panel);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-strong);
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 1.5rem 2rem;
  padding: clamp(1.2rem, 3vw, 2rem);
}
.exploration-start h2,
.exploration-phase h2,
.exploration-body h2 {
  font: 500 1.6rem/1.3 var(--font-serif);
  margin-block: 0 0.8rem;
}
.exploration-start p,
.exploration-context,
.exploration-note,
.exploration-phase small,
.exploration-return {
  font: 0.9rem/1.65 var(--font-ui);
}
.exploration-context {
  margin-block: 1.5rem 2rem;
}
.exploration-context nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.2rem;
  list-style: none;
  margin-block: 0.8rem;
  padding: 0;
}
.exploration-reading,
.exploration-discussion {
  border-top: 1px solid var(--border);
  margin-block: 0;
  padding-block: 0.6rem;
}
.exploration-reading > summary,
.exploration-discussion > summary {
  cursor: pointer;
  font: 650 1rem/1.5 var(--font-ui);
  padding-block: 0.6rem;
}
.exploration-body {
  font: 1rem/1.8 var(--font-serif);
  max-width: 46rem;
  overflow-x: auto;
  padding-block: 1.2rem;
}
.exploration-body h2:not(:first-child) {
  margin-top: 1.6rem;
}
.exploration-body .heading-anchor {
  position: static;
  margin-inline-start: 0.5rem;
  opacity: 0.65;
}
.exploration-body li {
  margin-bottom: 1rem;
}
.exploration-body pre {
  background: var(--panel);
  font: 0.8rem/1.6 var(--font-mono);
  overflow-x: auto;
  padding: 1rem;
}
.exploration-body table {
  border-collapse: collapse;
  font: 0.85rem/1.5 var(--font-ui);
  width: 100%;
}
.exploration-body th,
.exploration-body td {
  border-bottom: 1px solid var(--border);
  padding: 0.7rem;
  text-align: left;
}
.exploration-phase {
  border-top: 1px solid var(--border);
  padding-top: 1.2rem;
  margin-top: 2rem;
}
.exploration-phase ul {
  list-style: none;
  margin: 0;
  padding: 0;
}
.exploration-phase li {
  max-width: 46rem;
  margin-block: 1.4rem;
}
.exploration-phase li > a {
  font: 500 1.35rem/1.4 var(--font-serif);
}
.exploration-phase li > p {
  margin-block: 0.4rem;
}
.exploration-note {
  color: var(--muted);
  margin-top: 1.5rem;
}
.exploration-page [hidden] {
  display: none;
}
.exploration-page a,
.exploration-page summary {
  text-underline-offset: 0.2em;
}
.exploration-page a:focus-visible,
.exploration-page summary:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 4px;
}
@media (max-width: 48rem) {
  .exploration-start {
    grid-template-columns: minmax(0, 1fr);
  }
}
@media print {
  .exploration-start {
    display: block;
  }
  .exploration-page details > div {
    display: block;
  }
}

.learning-workspace {
  position: fixed;
  inset: 5rem 1rem 1rem auto;
  margin: 0;
  width: min(31rem, calc(100vw - 2rem));
  height: calc(100dvh - 6rem);
  max-height: calc(100vh - 6rem);
  max-height: calc(100dvh - 6rem);
  box-sizing: border-box;
  padding: 0;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-top: 4px solid var(--accent);
  box-shadow: var(--shadow);
  z-index: 80;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.learning-workspace[hidden] {
  display: none;
}
.learning-workspace[data-learning-experience="assistant"] {
  inset: auto 1rem 1rem auto;
  width: min(29rem, calc(100vw - 2rem));
  height: min(38rem, calc(100dvh - 6rem));
  border-radius: 0.6rem 0.6rem 0 0;
}
body[data-learning-notebook-open="true"][data-learning-assistant-open="true"] {
  --learning-assistant-height: min(32rem, 48dvh);
}
body[data-learning-notebook-open="true"][data-learning-assistant-open="true"]
  .learning-workspace[data-learning-experience="notebook"] {
  inset-block-end: calc(var(--learning-assistant-height) + 2rem);
  height: calc(100dvh - var(--learning-assistant-height) - 7rem);
  max-height: calc(100dvh - var(--learning-assistant-height) - 7rem);
}
body[data-learning-notebook-open="true"][data-learning-assistant-open="true"]
  .learning-workspace[data-learning-experience="assistant"] {
  height: var(--learning-assistant-height);
  max-height: var(--learning-assistant-height);
}
body[data-learning-notebook-open="true"][data-learning-assistant-open="true"]
  .learning-note-input {
  height: 7rem;
}
.learning-heading {
  display: flex;
  justify-content: space-between;
  align-items: start;
  padding: 0.75rem 1rem 0.4rem;
}
.learning-chrome {
  flex: none;
  background: var(--bg);
}
.learning-content {
  flex: 1;
  min-height: 0;
  overflow: auto;
}
.learning-heading h2 {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 500;
  margin: 0.1rem 0;
}
.learning-purpose {
  margin: 0.25rem 0 0;
  color: var(--muted);
  font-size: 0.75rem;
}
.learning-eyebrow {
  color: var(--muted);
  font-size: 0.7rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  margin: 0;
}
.learning-heading button {
  font-size: 1.4rem;
  padding: 0.2rem 0.6rem;
}
.learning-tabs {
  padding: 0 1rem;
  border-bottom: 1px solid var(--border);
}
.learning-tab-primary,
.learning-tools-menu {
  display: flex;
  gap: 0.3rem;
  overflow-x: auto;
}
.learning-workspace .learning-tabs button {
  border: 0;
  border-bottom: 3px solid transparent;
  border-radius: 0;
  padding: 0.45rem 0.5rem;
  white-space: nowrap;
  font-size: 0.8rem;
}
.learning-workspace .learning-tabs button[aria-current="true"] {
  border-color: var(--accent);
  color: var(--accent-strong);
}
.learning-tools > summary {
  padding: 0.25rem 0;
  font-size: 0.75rem;
  color: var(--muted);
}
.learning-tools-menu {
  flex-wrap: wrap;
}
.learning-status {
  padding: 0 1.4rem;
  color: var(--accent-strong);
  font-size: 0.85rem;
}
.learning-status:empty {
  display: none;
}
.learning-selection {
  padding: 0.6rem 1.4rem;
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem;
}
.learning-selection p {
  margin: 0 0 0.4rem;
  overflow-wrap: anywhere;
}
.learning-body {
  padding: 0.75rem 1rem 1rem;
  font-size: 0.9rem;
  line-height: 1.55;
}
.learning-body > * + * {
  margin-top: 0.9rem;
}
.learning-workspace label {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin: 0.8rem 0;
}
.learning-workspace label.learning-checkbox {
  flex-direction: row;
  align-items: start;
  justify-content: space-between;
}
.learning-workspace label > span {
  font-weight: 600;
  font-size: 0.8rem;
}
.learning-workspace input:not([type="checkbox"]),
.learning-workspace select,
.learning-workspace textarea {
  width: 100%;
  box-sizing: border-box;
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 0;
  padding: 0.65rem;
  font: inherit;
}
.learning-workspace textarea {
  resize: vertical;
  line-height: 1.6;
}
.learning-workspace button {
  cursor: pointer;
  color: var(--accent-strong);
  background: transparent;
  border: 1px solid var(--border);
  padding: 0.5rem 0.75rem;
  font: inherit;
}
.learning-workspace button + button,
.learning-workspace button + a {
  margin-left: 0.5rem;
}
.learning-workspace button.learning-primary {
  background: var(--accent-strong);
  color: var(--bg);
  border-color: var(--accent-strong);
}
.learning-workspace button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}
.learning-workspace button:focus-visible,
.learning-workspace a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}
.learning-hint {
  color: var(--muted);
  font-size: 0.8rem;
}
.learning-context {
  border-left: 3px solid var(--accent);
  padding-left: 0.9rem;
}
.learning-workspace summary {
  cursor: pointer;
  font-weight: 600;
}
.learning-workspace blockquote {
  margin: 1rem 0;
  color: var(--muted);
  max-height: 9rem;
  overflow-y: auto;
  overflow-wrap: anywhere;
}
.learning-context > a {
  display: block;
  font-weight: 600;
  line-height: 1.4;
}
.learning-context p {
  margin: 0.25rem 0;
}
.learning-assistant-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.learning-assistant-actions button + button {
  margin-left: 0;
}
.learning-guide-step {
  margin-top: 1.25rem;
  padding-top: 0.8rem;
  border-top: 1px solid var(--border);
}
.learning-guide-feedback {
  color: var(--accent-strong);
  font-size: 0.85rem;
  scroll-margin-top: 12rem;
}
.learning-guide-feedback:empty {
  display: none;
}
.learning-workspace h3 {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  margin: 0.6rem 0;
}
.learning-note {
  border-top: 1px solid var(--border);
  padding: 0.8rem 0;
}
.learning-note p {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}
.learning-reply {
  overflow-wrap: anywhere;
}
.learning-reply p {
  white-space: normal;
}
.learning-reply > :first-child {
  margin-top: 0;
}
.learning-reply ul,
.learning-reply ol {
  padding-left: 1.4rem;
}
.learning-reply pre,
.learning-reply-table,
.learning-math {
  max-width: 100%;
  overflow-x: auto;
}
.learning-reply pre {
  padding: 0.7rem;
  background: var(--panel);
  white-space: pre;
}
.learning-reply table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}
.learning-reply th,
.learning-reply td {
  padding: 0.45rem 0.6rem;
  border: 1px solid var(--border);
  text-align: left;
}
.learning-reply th {
  background: var(--panel);
}
.learning-math .katex-mathml {
  position: static;
}
.learning-provider-readiness {
  margin: 0.75rem 0;
  padding: 0.6rem 0.8rem;
  border-left: 2px solid var(--accent-strong);
  font-size: 0.85rem;
}
.learning-storage-location,
.learning-observation {
  overflow-wrap: anywhere;
  white-space: pre-wrap;
}
.learning-observation {
  max-height: 14rem;
  overflow-y: auto;
  padding: 0.7rem;
  background: var(--panel);
  font-size: 0.75rem;
}
.learning-observation:empty {
  display: none;
}
.learning-note details {
  margin: 0.5rem 0;
}
@media (max-width: 640px) {
  .learning-workspace,
  .learning-workspace[data-learning-experience="assistant"] {
    inset: auto 0 0 auto;
    width: 100%;
    height: 80dvh;
    max-height: 80dvh;
    border-radius: 0.6rem 0.6rem 0 0;
  }
  .learning-heading {
    padding-top: 1rem;
  }
  .learning-body {
    padding: 1rem;
  }
}

.reading-investigation {
  scroll-margin-block-start: 7rem;
  overflow-wrap: anywhere;
  margin-block: 1.5rem 2.5rem;
  padding: clamp(1rem, 3vw, 1.8rem);
  border-block-start: 3px solid var(--accent);
  border-inline-start: 1px solid var(--border);
  background: var(--panel);
}
.reading-investigation [hidden] {
  display: none !important;
}
.reading-investigation p {
  font-size: 1rem;
  line-height: 1.6;
  margin-block: 0.7rem;
}
.reading-investigation .reading-investigation-kicker {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.13em;
  margin-block: 0 0.5rem;
}
.reading-investigation h3 {
  margin-block: 0.3rem 0.7rem;
}
.reading-investigation h2 {
  font-size: clamp(1.3rem, 3vw, 1.8rem);
  line-height: 1.25;
  margin-block: 0.3rem 0.7rem;
}
.cockpit-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.cockpit-heading nav {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.learning-cockpit[data-tutorial-active="true"]
  > :not(.cockpit-heading):not(.learning-tutorial) {
  display: none !important;
}
.learning-tutorial {
  margin-block: 1.5rem;
  padding-block: 1.25rem;
  border-block: 1px solid var(--accent);
}
.learning-tutorial .tutorial-kicker {
  font: 600 0.75rem/1.4 var(--font-ui);
  letter-spacing: 0.12em;
  color: var(--accent-strong);
}
.tutorial-progress {
  display: flex;
  list-style: none;
  gap: 0.4rem;
  padding: 0;
  margin-block: 1rem;
}
.tutorial-progress li {
  display: grid;
  place-items: center;
  inline-size: 1.75rem;
  block-size: 1.75rem;
  border: 1px solid var(--border);
  font: 500 0.8rem/1 var(--font-ui);
}
.tutorial-progress [aria-current] {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}
.tutorial-illustration,
.tutorial-example {
  margin-block: 1.25rem;
  padding: 1rem;
  border-inline-start: 3px solid var(--accent);
  background: var(--bg);
}
.tutorial-illustration dl {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 0.5rem 1rem;
  font-variant-numeric: tabular-nums;
}
.tutorial-illustration dd {
  margin: 0;
  font-weight: 700;
}
.tutorial-preview p {
  white-space: pre-wrap;
}
.tutorial-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-block-start: 1.25rem;
}
.tutorial-actions button:nth-last-child(2) {
  border-width: 2px;
  font-weight: 700;
}
.reading-investigation select {
  box-sizing: border-box;
  inline-size: 100%;
  min-inline-size: 0;
  max-inline-size: 100%;
  padding: 0.65rem;
  background: var(--panel);
  color: inherit;
  border: 1px solid var(--border);
  font: inherit;
}
.learning-loop-launch {
  display: inline-block;
  color: var(--accent-strong);
  background: var(--panel);
  border: 1px solid var(--accent);
  border-radius: 0.2rem;
  padding: 0.6rem 1rem;
  font: 600 0.85rem/1.3 var(--font-ui);
  cursor: pointer;
  margin-block: 0.5rem 1.5rem;
}
.learning-loop-launch:focus-visible,
.reading-investigation select:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 3px;
}
.cockpit-trail {
  border-block-start: 1px solid var(--border);
  padding-block-start: 0.75rem;
}
.reading-investigation .cockpit-trail p {
  color: var(--muted);
  font-size: 0.85rem;
}
@media print {
  .learning-loop-launch,
  .learning-cockpit {
    display: none;
  }
}
.reading-investigation h4 {
  font-size: 1rem;
  margin-block: 1rem 0.5rem;
}
.reading-investigation button {
  padding: 0.55rem 0.8rem;
  font: inherit;
  color: inherit;
  border: 1px solid currentColor;
  border-radius: 0.2rem;
  background: transparent;
  cursor: pointer;
  white-space: normal;
}
.reading-investigation button:disabled {
  opacity: 0.5;
  cursor: default;
}
.reading-investigation button:focus-visible,
.reading-investigation textarea:focus-visible,
.reading-investigation input:focus-visible {
  outline: 2px solid currentColor;
  outline-offset: 3px;
}
.reading-investigation-steps {
  list-style: none;
  display: flex;
  gap: 0.5rem;
  padding: 0;
  margin-block: 1.5rem 1rem;
  flex-wrap: wrap;
}
.reading-investigation-steps li {
  padding: 0;
  margin: 0;
}
.reading-investigation-steps button {
  font-size: 0.8rem;
  border-color: transparent;
}
.reading-investigation-steps [aria-current="true"] {
  border-color: currentColor;
  font-weight: 700;
}
.reading-investigation-prompt {
  font-weight: 600;
}
.reading-investigation label {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.4rem;
  margin-block: 1rem;
}
.reading-investigation label > span {
  font-size: 0.9rem;
  font-weight: 600;
}
.reading-investigation .cockpit-focus {
  display: block;
}
.cockpit-focus > span {
  display: block;
  margin-block-end: 0.4rem;
}
.reading-investigation textarea,
.reading-investigation input {
  box-sizing: border-box;
  inline-size: 100%;
  min-inline-size: 0;
  color: inherit;
  background: transparent;
  border: 1px solid currentColor;
  border-radius: 0.2rem;
  padding: 0.7rem;
  font: inherit;
}
.reading-investigation textarea {
  resize: vertical;
}
.reading-investigation-connection {
  font-size: 0.85rem;
}
.reading-investigation-connection p {
  font: 0.85rem/1.5 var(--font-ui);
}
.reading-investigation-connection button {
  margin-block-start: 0.6rem;
  margin-inline-end: 0.5rem;
}
.reading-investigation-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}
.reading-investigation-actions button:first-child {
  font-weight: 700;
  border-width: 2px;
}
.reading-investigation-observation {
  padding-inline-start: 0.8rem;
  border-inline-start: 2px solid currentColor;
  font-variant-numeric: tabular-nums;
}
.reading-investigation-hint {
  font-size: 0.8rem;
  line-height: 1.5;
}
.reading-investigation-hint p {
  font: 0.85rem/1.5 var(--font-ui);
}
.reading-investigation-messages {
  margin-block: 1rem;
  overflow-wrap: anywhere;
}
.reading-investigation-messages:not(:empty) {
  padding-block: 0.5rem 1rem;
  border-block: 1px solid currentColor;
}
.reading-investigation details {
  margin-block: 0.8rem;
}
.reading-investigation summary {
  cursor: pointer;
}

.account-toggle {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  color: var(--text);
  cursor: pointer;
  font: 600 0.82rem var(--font-ui);
  padding: 0.65rem 0.8rem;
}
.account-toggle[hidden] {
  display: none;
}
.account-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent-strong);
  border-radius: 0.5rem;
  box-shadow: var(--shadow);
  color: var(--text);
  font: 0.9rem/1.55 var(--font-ui);
  inline-size: min(30rem, calc(100vw - 2rem));
  max-block-size: calc(100dvh - 3rem);
  padding: 1.4rem;
  box-sizing: border-box;
  overflow: auto;
}
.account-panel::backdrop {
  background: rgb(0 0 0 / 30%);
}
.account-heading {
  display: flex;
  justify-content: space-between;
  align-items: start;
  gap: 1rem;
}
.account-eyebrow {
  color: var(--accent-strong);
  font: 0.72rem var(--font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin: 0 0 0.5rem;
}
.account-panel h2 {
  font-size: 1.3rem;
  margin: 0;
}
.account-panel h3 {
  font-size: 1rem;
  margin: 0 0 0.5rem;
}
.account-panel section {
  padding-block: 1rem;
  border-bottom: 1px solid var(--border);
}
.account-panel p {
  margin-block: 0.5rem;
  overflow-wrap: anywhere;
}
.account-panel form,
.account-panel label {
  display: grid;
  gap: 0.5rem;
}
.account-panel form {
  margin-block: 0.8rem;
  gap: 0.8rem;
}
.account-panel label {
  font-size: 0.82rem;
  margin-block: 0.6rem;
}
.account-panel input,
.account-panel select {
  box-sizing: border-box;
  min-inline-size: 0;
  inline-size: 100%;
  padding: 0.6rem;
  background: var(--bg);
  border: 1px solid var(--muted);
  color: var(--text);
  font: inherit;
}
.account-panel button {
  padding: 0.6rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: 0.3rem;
  background: var(--bg);
  color: var(--text);
  font: 600 0.82rem var(--font-ui);
  cursor: pointer;
}
.account-panel button[type="submit"] {
  background: var(--accent-strong);
  color: var(--panel);
  border-color: var(--accent-strong);
}
.account-panel button:disabled {
  opacity: 0.55;
  cursor: default;
}
.account-panel a {
  display: inline-block;
  margin-block: 0.4rem;
}
.account-panel :focus-visible,
.account-toggle:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 3px;
}
[data-account-status]:empty {
  display: none;
}
[data-account-body] > button {
  margin-top: 0.8rem;
}
@media print {
  .account-toggle,
  .account-panel {
    display: none;
  }
}