/* Reader-first information architecture and overflow guardrails.
   Loaded after site.css so this file can refine layout without changing the
   source/Lean site generator. */

html,
body {
  max-width: 100%;
  overflow-x: clip;
}

.site-stage,
.site-stage main,
.site-stage main > *,
.chapter-card > *,
.route-row > *,
.two-column > *,
.split > *,
.theorem-grid > *,
.source-grid > *,
.card-grid > *,
.metric-row > * {
  min-width: 0;
}

.site-stage main {
  max-width: 980px;
  padding-inline: clamp(1rem, 2.6vw, 1.75rem);
}

main > section {
  margin: 3.6rem 0;
}

.page-hero,
.page-hero.compact {
  padding-top: 3.6rem;
  margin-bottom: 2.2rem;
}

.page-hero.compact h1,
.live-hero h1,
.overview-hero h1 {
  max-width: 24ch;
  font-size: clamp(2.35rem, 5vw, 3.45rem);
  line-height: 1.02;
}

.ia-home-hero {
  margin-top: 0;
  padding: 5rem 0 0.6rem;
}

.ia-home-hero h1 {
  max-width: 14ch;
  margin-bottom: 1rem;
  font-size: clamp(3rem, 7vw, 5.2rem);
  line-height: 0.96;
  letter-spacing: -0.045em;
}

.ia-home-hero .lede,
.ia-compact-hero .lede {
  max-width: 64ch;
}

.section-heading {
  margin-bottom: 1.35rem;
}

.section-heading h2 {
  max-width: 30ch;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.03;
}

.lede {
  overflow-wrap: anywhere;
}

/* Sidebar: two first-class sources, everything else subordinate. */
.sidebar-contents {
  gap: 0.85rem;
}

.sidebar-libraries {
  padding-bottom: 0.15rem;
}

.source-hubs {
  gap: 0.45rem !important;
}

.sidebar-group .source-hub {
  display: grid;
  gap: 0.13rem;
  align-items: start;
  padding: 0.65rem 0.7rem;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 9px;
}

.sidebar-group .source-hub:hover,
.sidebar-group .source-hub[aria-current="page"] {
  color: var(--ink);
  border-color: color-mix(in srgb, var(--accent) 42%, var(--line));
  background: var(--accent-soft);
}

.source-hub-title {
  color: var(--ink);
  font-size: 0.92rem;
  font-weight: 720;
  line-height: 1.2;
}

.source-hub small {
  color: var(--muted);
  font-size: 0.65rem;
  font-weight: 550;
  line-height: 1.35;
}

.book-nav,
.sidebar-more {
  margin: 0;
  padding: 0;
  border: 0;
}

.book-nav > summary,
.sidebar-more > summary {
  padding: 0.42rem 0.55rem;
  color: var(--muted);
  border-radius: 6px;
  font-size: 0.72rem;
  font-weight: 700;
  cursor: pointer;
}

.book-nav > summary:hover,
.sidebar-more > summary:hover {
  color: var(--ink);
  background: var(--surface-2);
}

.compact-book-toc {
  display: grid;
  gap: 0.08rem;
  margin-top: 0.3rem;
}

.toc-part.compact {
  margin: 0.65rem 0 0.18rem;
  padding: 0 0.55rem;
  color: var(--muted);
  font-size: 0.61rem;
  line-height: 1.25;
}

.toc-part.compact span {
  margin-right: 0.4rem;
  color: var(--accent);
  font-weight: 700;
  text-transform: uppercase;
}

.book-nav .compact-chapter-link {
  display: grid;
  grid-template-columns: 1.7rem minmax(0, 1fr);
  gap: 0.4rem;
  padding: 0.31rem 0.55rem;
  color: var(--muted);
  border-radius: 6px;
  font-size: 0.69rem;
  line-height: 1.28;
  text-decoration: none;
}

.book-nav .compact-chapter-link span,
.current-chapter-sections a span {
  color: var(--accent);
  font: 500 0.61rem var(--font-code);
}

.book-nav .compact-chapter-link strong {
  min-width: 0;
  overflow-wrap: anywhere;
  font-weight: 590;
}

.book-nav .compact-chapter-link:hover,
.book-nav .compact-chapter-link[aria-current="page"] {
  color: var(--ink);
  background: var(--surface-2);
}

.current-chapter-sections {
  display: grid;
  gap: 0.05rem;
  margin: 0.14rem 0 0.42rem 1.55rem;
  padding-left: 0.4rem;
  border-left: 1px solid var(--line);
}

.current-chapter-sections a,
.sidebar-more nav a {
  display: grid;
  grid-template-columns: 2.2rem minmax(0, 1fr);
  gap: 0.3rem;
  padding: 0.28rem 0.42rem;
  color: var(--muted);
  border-radius: 5px;
  font-size: 0.65rem;
  line-height: 1.28;
  text-decoration: none;
  overflow-wrap: anywhere;
}

.current-chapter-sections a:hover,
.current-chapter-sections a[aria-current="page"],
.sidebar-more nav a:hover {
  color: var(--ink);
  background: var(--surface-2);
}

.sidebar-more nav {
  display: grid;
  margin-top: 0.2rem;
}

.sidebar-more nav a {
  grid-template-columns: 1fr;
  padding-left: 0.7rem;
}

/* Two equal home portals. */
.source-portal-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 1.4rem;
}

.source-portal {
  display: flex;
  min-width: 0;
  min-height: 370px;
  flex-direction: column;
  padding: clamp(1.4rem, 3vw, 2rem);
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 14px;
  box-shadow: 0 10px 32px rgba(33, 45, 70, 0.055);
}

.source-portal-book {
  border-top: 4px solid var(--accent);
}

.source-portal-wiki {
  border-top: 4px solid var(--rigorous);
}

.portal-kicker {
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 750;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.source-portal h2 {
  margin: 0.55rem 0 0.75rem;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1;
  letter-spacing: -0.035em;
}

.source-portal p {
  max-width: 54ch;
  color: var(--muted);
}

.portal-metric {
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
  margin-top: auto;
  padding-top: 1.4rem;
}

.portal-metric strong {
  font: 680 2.25rem var(--font-display);
}

.portal-metric span {
  color: var(--muted);
  font-size: 0.74rem;
}

.portal-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.8rem;
  margin-top: 1rem;
}

.portal-actions > a:not(.button) {
  font-size: 0.78rem;
  font-weight: 650;
  text-decoration: none;
}

.ia-shortcuts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  overflow: hidden;
  margin: 1.1rem 0 4rem;
  border: 1px solid var(--line);
  background: var(--line);
  border-radius: 10px;
}

.ia-shortcuts a {
  display: grid;
  min-width: 0;
  gap: 0.2rem;
  padding: 1rem 1.15rem;
  color: var(--ink);
  background: var(--surface);
  text-decoration: none;
}

.ia-shortcuts a:hover {
  background: var(--surface-2);
}

.ia-shortcuts span,
.companion-tools span {
  color: var(--accent);
  font-size: 0.62rem;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.ia-shortcuts strong {
  overflow-wrap: anywhere;
  font-size: 0.86rem;
}

.zoom-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.8rem;
}

.zoom-grid article,
.companion-support-grid article {
  min-width: 0;
  padding: 1.1rem;
  border-top: 1px solid var(--line);
}

.zoom-grid article > span {
  color: var(--accent);
  font: 600 0.66rem var(--font-code);
}

.zoom-grid h3 {
  margin: 0.5rem 0 0.35rem;
}

.zoom-grid p,
.companion-support-grid p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.ia-project-note {
  padding: 1rem 1.15rem;
  color: var(--muted);
  border-left: 3px solid var(--accent);
  background: var(--surface-2);
  border-radius: 0 8px 8px 0;
  font-size: 0.86rem;
}

/* Study Guide: deliberately no declaration dump. */
.study-route {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
}

.study-route > a,
.chapter-one-route > a,
.companion-tools > a {
  display: grid;
  min-width: 0;
  gap: 0.25rem;
  padding: 1rem;
  color: var(--ink);
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 9px;
  text-decoration: none;
}

.study-route > a:hover,
.chapter-one-route > a:hover,
.companion-tools > a:hover {
  border-color: color-mix(in srgb, var(--accent) 45%, var(--line));
  background: var(--accent-soft);
}

.study-route span,
.chapter-one-route span {
  color: var(--accent);
  font: 600 0.66rem var(--font-code);
}

.study-route strong,
.chapter-one-route strong,
.companion-tools strong {
  overflow-wrap: anywhere;
  font-size: 0.9rem;
}

.study-route small,
.chapter-one-route small,
.companion-tools small {
  color: var(--muted);
  font-size: 0.68rem;
  line-height: 1.35;
}

.chapter-one-route {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.7rem;
}

.study-parts {
  display: grid;
  gap: 0.7rem;
}

.study-part {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 9px;
}

.study-part > summary {
  padding: 0.85rem 1rem;
  font-weight: 680;
  cursor: pointer;
}

.study-chapter-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  border-top: 1px solid var(--line);
  background: var(--line);
}

.study-chapter-links a {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  gap: 0.55rem;
  min-width: 0;
  padding: 0.72rem 0.9rem;
  color: var(--ink);
  background: var(--surface);
  text-decoration: none;
}

.study-chapter-links a:hover {
  background: var(--surface-2);
}

.study-chapter-links span {
  color: var(--accent);
  font: 600 0.65rem var(--font-code);
}

.study-chapter-links strong {
  min-width: 0;
  overflow-wrap: anywhere;
  font-size: 0.78rem;
  line-height: 1.35;
}

/* Proof Atlas: layers and domain clusters replace a giant default DAG. */
.atlas-layers {
  display: grid;
  max-width: 760px;
  gap: 0.5rem;
  margin-inline: auto;
}

.atlas-layer {
  min-width: 0;
  padding: 1.15rem 1.25rem;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 10px;
}

.atlas-layer-label {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 0.6rem;
}

.atlas-layer-label span {
  color: var(--accent);
  font: 600 0.65rem var(--font-code);
}

.atlas-layer-label strong {
  font-size: 1rem;
}

.atlas-layer p {
  margin: 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.atlas-source-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.65rem;
}

.atlas-source-grid a {
  padding: 0.75rem;
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 0.86rem;
  font-weight: 700;
  text-align: center;
  text-decoration: none;
}

.atlas-arrow {
  color: var(--muted);
  font-size: 1rem;
  line-height: 1;
  text-align: center;
}

.atlas-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 0.75rem;
}

.atlas-actions a {
  font-size: 0.78rem;
  font-weight: 650;
  text-decoration: none;
}

.proof-cluster-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.85rem;
}

.proof-cluster {
  min-width: 0;
  padding: 1.15rem;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 10px;
}

.proof-cluster > span {
  color: var(--accent);
  font: 600 0.66rem var(--font-code);
}

.proof-cluster h3 {
  margin: 0.5rem 0 0.45rem;
}

.proof-cluster p {
  color: var(--muted);
  font-size: 0.86rem;
}

.root-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.root-tags code {
  max-width: 100%;
  padding: 0.2rem 0.38rem;
  border: 1px solid var(--line);
  background: var(--surface-2);
  border-radius: 5px;
  font-size: 0.64rem;
  overflow-wrap: anywhere;
}

.atlas-status-section p {
  max-width: 68ch;
  color: var(--muted);
}

.status-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 0.8rem;
}

.ia-disclosure {
  margin: 2rem 0 4rem;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 9px;
}

.ia-disclosure summary {
  padding: 0.85rem 1rem;
  font-weight: 650;
  cursor: pointer;
}

.ia-disclosure > div {
  padding: 0 1rem 1rem;
  color: var(--muted);
}

/* Chapter 1 companion. */
.companion-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.8rem;
}

.companion-grid article {
  min-width: 0;
  padding: 1.25rem;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 10px;
}

.companion-grid article > span {
  color: var(--accent);
  font: 600 0.68rem var(--font-code);
}

.companion-grid h2 {
  margin: 0.55rem 0 0.5rem;
  font-size: 1.45rem;
}

.companion-grid p {
  color: var(--muted);
  font-size: 0.88rem;
}

.companion-grid a {
  font-size: 0.78rem;
  font-weight: 650;
  text-decoration: none;
}

.companion-support-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.65rem;
}

.companion-support-grid h3 {
  margin: 0;
  font-size: 0.92rem;
}

.companion-tools {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.7rem;
}

/* Universal long-token / narrow-grid protection. */
main a,
main p,
main li,
main dt,
main dd,
main summary,
.card-meta,
.file-ref,
.theorem-mini h3,
.theorem-mini code,
.chapter-card h2,
.chapter-card code,
.correspondence-card,
.decl-links,
.module-links {
  min-width: 0;
  overflow-wrap: anywhere;
}

code:not(pre code) {
  max-width: 100%;
  overflow-wrap: anywhere;
  word-break: break-word;
}

pre,
.code-block,
.formula,
.table-wrap,
mjx-container[display="true"] {
  max-width: 100%;
}

pre.code-block,
.code-block {
  overflow-x: auto;
}

.diagram {
  max-width: 100%;
}

.diagram .mermaid {
  min-width: 0 !important;
  max-width: 100%;
}

.diagram svg,
img,
svg {
  max-width: 100%;
  height: auto;
}

.chapter-card,
.route-row {
  grid-template-columns: 72px minmax(0, 1fr);
  padding: 1.15rem;
}

.theorem-grid,
.source-grid,
.calculation-route {
  grid-template-columns: repeat(auto-fit, minmax(min(260px, 100%), 1fr));
}

.theorem-mini,
.source-card {
  min-width: 0;
}

.file-ref {
  display: block;
  margin-top: 0.65rem;
  word-break: break-word;
}

.metric-row {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.metric-row > div {
  min-width: 0;
  padding: 1rem;
}

.metric-row strong {
  overflow-wrap: anywhere;
  font-size: clamp(1.35rem, 3.5vw, 2rem);
}

.table-wrap {
  overflow-x: auto;
  overscroll-behavior-inline: contain;
}

@media (max-width: 900px) {
  main > section {
    margin: 3rem 0;
  }

  .source-portal-grid,
  .proof-cluster-grid,
  .companion-grid {
    grid-template-columns: 1fr;
  }

  .source-portal {
    min-height: 320px;
  }

  .chapter-one-route,
  .companion-support-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 700px) {
  .site-stage main {
    padding-inline: 1rem;
  }

  .ia-home-hero {
    padding-top: 3.2rem;
  }

  .ia-shortcuts,
  .zoom-grid,
  .study-route,
  .companion-tools,
  .study-chapter-links,
  .atlas-source-grid,
  .chapter-one-route,
  .companion-support-grid,
  .metric-row {
    grid-template-columns: 1fr;
  }

  .source-portal {
    min-height: 0;
  }

  .study-chapter-links a {
    grid-template-columns: 1.7rem minmax(0, 1fr);
  }

  .chapter-card,
  .route-row {
    grid-template-columns: 44px minmax(0, 1fr);
    gap: 0.75rem;
  }

  .diagram {
    padding: 0.75rem;
  }

  .diagram .mermaid {
    font-size: 0.75rem;
  }
}