:root {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --panel-muted: #eef2f5;
  --sidebar: #111820;
  --sidebar-soft: #17212b;
  --border: #dce2e8;
  --border-strong: #c6d0da;
  --text: #17202a;
  --text-soft: #445262;
  --text-muted: #6a7786;
  --text-inverse: #eef3f8;
  --accent: #0f766e;
  --accent-dark: #115e59;
  --accent-soft: #d9f2ee;
  --code-bg: #101820;
  --danger: #b42318;
  --warning: #9a6700;
  --success: #067647;
  --sidebar-width: 304px;
  --topbar-height: 58px;
  --radius: 8px;
  --font-sans: "DM Sans", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Consolas, monospace;
  --shadow: 0 18px 45px rgba(16, 24, 40, 0.08);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  color: var(--accent-dark);
}

code,
pre {
  font-family: var(--font-mono);
}

.app-shell {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  position: fixed;
  inset: 0 auto 0 0;
  z-index: 100;
  display: flex;
  width: var(--sidebar-width);
  flex-direction: column;
  background: var(--sidebar);
  border-right: 1px solid rgba(255, 255, 255, 0.08);
  transition: transform 0.22s ease;
}

.sidebar-brand {
  padding: 18px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-inverse);
}

.brand-link:hover {
  color: #ffffff;
}

.brand-logo {
  width: 38px;
  height: 38px;
  border-radius: var(--radius);
  object-fit: contain;
  flex-shrink: 0;
}

.brand-link strong,
.brand-link small {
  display: block;
}

.brand-link strong {
  font-size: 1rem;
}

.brand-link small {
  margin-top: 1px;
  color: #9facbb;
  font-size: 0.76rem;
}

.sidebar-search {
  padding: 14px 14px 10px;
}

.sidebar-search input {
  width: 100%;
  height: 40px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
  background: var(--sidebar-soft);
  color: var(--text-inverse);
  font: inherit;
  font-size: 0.9rem;
  outline: none;
  padding: 0 12px;
}

.sidebar-search input:focus {
  border-color: rgba(45, 212, 191, 0.55);
  box-shadow: 0 0 0 3px rgba(45, 212, 191, 0.16);
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 6px 10px 18px;
  scrollbar-width: thin;
  scrollbar-color: #314151 transparent;
}

.nav-group {
  margin-bottom: 4px;
}

.nav-group-title {
  list-style: none;
  cursor: pointer;
  border-radius: var(--radius);
  color: #aeb9c5;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 9px 10px;
  text-transform: uppercase;
}

.nav-group-title::-webkit-details-marker {
  display: none;
}

.nav-group-title::before {
  content: "";
  display: inline-block;
  width: 7px;
  height: 7px;
  margin-right: 8px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(-45deg) translateY(-1px);
  transition: transform 0.15s ease;
}

.nav-group[open] .nav-group-title::before {
  transform: rotate(45deg) translateY(-2px);
}

.nav-chapters {
  margin: 0;
  padding: 0 0 4px;
  list-style: none;
}

.nav-chapter-link {
  display: grid;
  grid-template-columns: 8px minmax(0, 1fr);
  gap: 8px;
  align-items: start;
  min-height: 34px;
  border-radius: var(--radius);
  color: #bdc7d2;
  font-size: 0.86rem;
  line-height: 1.35;
  padding: 8px 10px;
}

.nav-chapter-link:hover {
  background: var(--sidebar-soft);
  color: #ffffff;
}

.nav-chapter-link.active {
  background: rgba(15, 118, 110, 0.24);
  color: #99f6e4;
  font-weight: 600;
}

.nav-dot {
  width: 4px;
  height: 4px;
  margin-top: 7px;
  border-radius: 50%;
  background: #607080;
}

.nav-chapter-link.active .nav-dot {
  background: #5eead4;
}

.nav-group-flat {
  padding-top: 8px;
}

.main-column {
  display: flex;
  flex: 1;
  min-width: 0;
  margin-left: var(--sidebar-width);
  flex-direction: column;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 14px;
  height: var(--topbar-height);
  padding: 0 28px;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(12px);
}

.menu-toggle {
  display: none;
  width: 38px;
  height: 38px;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--panel);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 0 auto;
  border-radius: 2px;
  background: var(--text);
}

.topbar-breadcrumb {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  color: var(--text-muted);
  font-size: 0.88rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.topbar-breadcrumb a {
  color: var(--text-muted);
}

.topbar-breadcrumb .sep {
  margin: 0 7px;
  color: var(--border-strong);
}

.topbar-breadcrumb .muted {
  color: var(--text-soft);
}

.icon-link,
.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 700;
  line-height: 1;
}

.icon-link,
.btn-secondary {
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text-soft);
  padding: 0 13px;
}

.icon-link:hover,
.btn-secondary:hover {
  border-color: var(--border-strong);
  color: var(--text);
}

.btn-primary {
  background: var(--accent);
  color: #ffffff;
  padding: 0 15px;
}

.btn-primary:hover {
  background: var(--accent-dark);
  color: #ffffff;
}

.content-area {
  width: 100%;
  max-width: 1500px;
  margin: 0 auto;
  padding: 34px clamp(28px, 3.2vw, 58px) 56px;
}

.site-footer {
  padding: 18px 40px 30px;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.84rem;
}

.site-footer p {
  margin: 0;
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 90;
  background: rgba(15, 23, 42, 0.52);
}

.docs-home {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 36px;
  align-items: start;
  max-width: 1360px;
  padding: 12px 0 36px;
}

.home-intro {
  max-width: 860px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.home-intro h1 {
  margin: 0 0 10px;
  color: var(--text);
  font-size: clamp(2.35rem, 5vw, 4rem);
  line-height: 1.02;
}

.hero-subtitle {
  margin: 0 0 10px;
  color: var(--text-soft);
  font-size: 1.13rem;
}

.hero-desc {
  max-width: 760px;
  margin: 0;
  color: var(--text-muted);
  font-size: 1rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.quick-panel {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: var(--shadow);
  padding: 18px;
}

.quick-panel h2 {
  margin: 0 0 12px;
  font-size: 1rem;
}

.quick-links {
  display: grid;
  gap: 6px;
}

.quick-links a {
  display: flex;
  align-items: center;
  min-height: 38px;
  border-radius: var(--radius);
  color: var(--text-soft);
  font-size: 0.92rem;
  font-weight: 700;
  padding: 0 10px;
}

.quick-links a:hover {
  background: var(--accent-soft);
  color: var(--accent-dark);
}

.parts-grid,
.featured-chapters {
  margin-bottom: 40px;
}

.section-heading {
  margin-bottom: 14px;
}

.section-heading h2 {
  margin: 0;
  font-size: 1.35rem;
  line-height: 1.25;
}

.parts-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(245px, 1fr));
  gap: 12px;
}

.part-card,
.chapter-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--text);
  transition: border-color 0.15s ease, box-shadow 0.15s ease, transform 0.15s ease;
}

.part-card {
  padding: 16px;
}

.part-card:hover,
.chapter-card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow);
  color: var(--text);
  transform: translateY(-1px);
}

.part-number,
.chapter-card-label {
  color: var(--accent);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.part-card h3,
.chapter-card h3 {
  margin: 7px 0 8px;
  font-size: 1rem;
  line-height: 1.35;
}

.part-card p {
  margin: 0 0 12px;
  color: var(--text-muted);
  font-size: 0.88rem;
}

.part-link,
.chapter-card-arrow {
  color: var(--text-soft);
  font-size: 0.86rem;
  font-weight: 700;
}

.chapter-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 12px;
}

.chapter-card {
  display: block;
  padding: 16px;
}

.chapter-header {
  max-width: 1040px;
  margin-bottom: 28px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border);
}

.chapter-part {
  margin: 0 0 7px;
  color: var(--accent);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.chapter-header h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.08;
}

.chapter-layout {
  display: grid;
  grid-template-columns: minmax(0, 1040px) minmax(250px, 300px);
  gap: clamp(28px, 3vw, 52px);
  align-items: start;
  max-width: 1390px;
}

.chapter-toc {
  position: sticky;
  top: calc(var(--topbar-height) + 18px);
  max-height: calc(100vh - var(--topbar-height) - 36px);
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--panel);
}

.chapter-toc-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
}

.chapter-toc h2 {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.chapter-toc-count {
  color: var(--text-muted);
  font-size: 0.78rem;
}

.chapter-toc nav {
  max-height: calc(100vh - var(--topbar-height) - 100px);
  overflow-y: auto;
  padding: 8px;
}

.chapter-toc-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.chapter-toc-list a {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: 6px;
  border-radius: var(--radius);
  color: var(--text-muted);
  line-height: 1.35;
  padding: 7px 8px;
}

.chapter-toc-list a:hover,
.chapter-toc-list a.active {
  background: var(--accent-soft);
  color: var(--accent-dark);
}

.toc-number {
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.72rem;
}

.toc-label {
  display: -webkit-box;
  overflow: hidden;
  font-size: 0.84rem;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.toc-level-3 {
  padding-left: 10px;
}

.toc-level-4 {
  padding-left: 20px;
}

.prose {
  max-width: 1040px;
  color: var(--text-soft);
  font-size: 1rem;
}

.prose h1.chapter-heading {
  display: none;
}

.prose h2,
.prose h3,
.prose h4 {
  scroll-margin-top: calc(var(--topbar-height) + 16px);
  color: var(--text);
  line-height: 1.25;
}

.prose h2 {
  margin: 34px 0 12px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  font-size: 1.45rem;
}

.prose h2:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.prose h3 {
  margin: 26px 0 9px;
  font-size: 1.16rem;
}

.prose h4 {
  margin: 22px 0 7px;
  color: var(--text-soft);
  font-size: 1rem;
}

.prose p,
.prose li {
  color: var(--text-soft);
}

.prose p {
  margin: 0 0 13px;
}

.prose ul,
.prose ol {
  margin: 10px 0 16px;
  padding-left: 22px;
}

.prose li {
  margin: 4px 0;
}

.prose strong {
  color: var(--text);
}

.inline-code {
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--panel-muted);
  color: #0f4f4a;
  font-size: 0.9em;
  padding: 0.1rem 0.35rem;
}

.code-block {
  margin: 18px 0;
  overflow-x: auto;
  border: 1px solid #1f2937;
  border-radius: var(--radius);
  background: var(--code-bg);
  color: #d7e1ea;
  font-size: 0.86rem;
  line-height: 1.55;
  padding: 15px 16px;
}

.code-block code {
  display: block;
  color: inherit;
  font: inherit;
  white-space: pre;
}

.code-block p,
.code-block span {
  color: inherit;
  font: inherit;
}

.table-wrap {
  margin: 18px 0;
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--panel);
}

.docs-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.docs-table th,
.docs-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
}

.docs-table th {
  background: var(--panel-muted);
  color: var(--text);
  font-weight: 800;
}

.docs-table tr:last-child td {
  border-bottom: 0;
}

.docs-image {
  max-width: 100%;
  margin: 16px 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.description-list {
  display: grid;
  gap: 6px 14px;
  grid-template-columns: minmax(140px, 0.35fr) minmax(0, 1fr);
  margin: 16px 0;
}

.description-list dt {
  color: var(--text);
  font-weight: 800;
}

.description-list dd {
  margin: 0;
  color: var(--text-soft);
}

.callout {
  margin: 18px 0;
  border: 1px solid var(--border);
  border-left-width: 4px;
  border-radius: var(--radius);
  background: var(--panel);
  padding: 14px 16px;
}

.callout-title {
  margin-bottom: 6px;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.callout-scope,
.callout-context,
.callout-output {
  border-left-color: var(--accent);
}

.callout-scope .callout-title,
.callout-context .callout-title,
.callout-output .callout-title {
  color: var(--accent);
}

.callout-ethics,
.callout-decision {
  border-left-color: var(--danger);
}

.callout-ethics .callout-title,
.callout-decision .callout-title {
  color: var(--danger);
}

.callout-warning {
  border-left-color: var(--warning);
}

.callout-warning .callout-title {
  color: var(--warning);
}

.callout-note {
  border-left-color: var(--border-strong);
}

.callout-note .callout-title {
  color: var(--text-soft);
}

.chapter-pagination {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  max-width: 1040px;
  margin-top: 42px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.page-link {
  display: block;
  min-height: 82px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--text);
  padding: 13px 15px;
}

.page-link:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow);
  color: var(--text);
}

.page-link small {
  display: block;
  margin-bottom: 4px;
  color: var(--text-muted);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.page-link span {
  font-weight: 800;
  line-height: 1.35;
}

.page-link.next {
  text-align: right;
}

blockquote {
  margin: 18px 0;
  border-left: 4px solid var(--border-strong);
  color: var(--text-soft);
  padding: 2px 0 2px 16px;
}

.text-center {
  text-align: center;
}

@media (max-width: 1120px) {
  .docs-home,
  .chapter-layout {
    grid-template-columns: 1fr;
  }

  .quick-panel {
    box-shadow: none;
  }

  .chapter-toc {
    position: static;
    max-height: none;
    order: -1;
  }

  .chapter-toc nav {
    max-height: 230px;
  }
}

@media (max-width: 900px) {
  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-overlay.visible {
    display: block;
  }

  .main-column {
    margin-left: 0;
  }

  .menu-toggle {
    display: flex;
  }

  .topbar {
    padding: 0 14px;
  }

  .content-area {
    padding: 24px 16px 42px;
  }

  .site-footer {
    padding: 16px;
  }

  .chapter-pagination {
    grid-template-columns: 1fr;
  }

  .page-link.next {
    text-align: left;
  }
}

@media (max-width: 560px) {
  .sidebar {
    width: min(88vw, var(--sidebar-width));
  }

  .home-intro h1 {
    font-size: 2.4rem;
  }

  .hero-actions {
    display: grid;
  }

  .description-list {
    grid-template-columns: 1fr;
  }

  .icon-link {
    display: none;
  }
}