/* =========================================================
   State of AI — stateofai.pages.dev
   Design: executive consulting aesthetic, IBM Plex, minimal
   ========================================================= */

:root {
  --font-body: 'IBM Plex Serif', Georgia, 'Times New Roman', serif;
  --font-ui: 'IBM Plex Sans', system-ui, -apple-system, sans-serif;
  --color-bg: #FAFAF8;
  --color-text: #1A1A18;
  --color-accent: #1C3A5E;
  --color-accent-hover: #15304e;
  --color-muted: #6B6B68;
  --color-rule: #E2E0DC;
  --color-card-bg: #F3F2EF;
  --color-card-hover: #ECEAE6;
  --measure: 68ch;
  --sidebar-width: 220px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 18px; scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

a:hover { color: var(--color-accent-hover); text-decoration: underline; }

/* ---- HEADER & NAV ---------------------------------------- */

.site-header {
  border-bottom: 1px solid var(--color-rule);
  background: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-nav {
  font-family: var(--font-ui);
  display: flex;
  align-items: center;
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 56px;
}

.site-logo {
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text);
  text-decoration: none;
  flex-shrink: 0;
}

.site-logo:hover { color: var(--color-accent); text-decoration: none; }

.nav-links {
  display: flex;
  gap: 1.5rem;
  margin-left: auto;
}

.nav-link {
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-muted);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

.nav-link:hover, .nav-link.active {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
  text-decoration: none;
}

/* ---- PAGE LAYOUT ----------------------------------------- */

.page-layout {
  display: flex;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  gap: 3rem;
  min-height: calc(100vh - 56px - 64px);
}

/* ---- SIDEBAR --------------------------------------------- */

.sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  padding-top: 2.5rem;
  padding-bottom: 2rem;
}

.sidebar-section {
  margin-bottom: 2rem;
}

.sidebar-heading {
  font-family: var(--font-ui);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-rule);
}

.sidebar-link {
  display: block;
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--color-muted);
  text-decoration: none;
  padding: 0.3rem 0;
  border-left: 2px solid transparent;
  padding-left: 0.75rem;
  margin-left: -0.75rem;
  transition: color 0.15s, border-color 0.15s;
  line-height: 1.4;
}

.sidebar-link:hover {
  color: var(--color-text);
  text-decoration: none;
  border-left-color: var(--color-rule);
}

.sidebar-link.active {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
  font-weight: 500;
}

/* ---- MAIN CONTENT ---------------------------------------- */

.main-content {
  flex: 1;
  min-width: 0;
  padding-top: 2.5rem;
  padding-bottom: 4rem;
}

/* ---- DOCUMENT -------------------------------------------- */

.doc-article {
  max-width: var(--measure);
}

.doc-meta {
  margin-bottom: 2rem;
}

.back-link {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--color-muted);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.back-link:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.doc-body h1 {
  font-family: var(--font-body);
  font-size: 1.8rem;
  font-weight: 500;
  line-height: 1.25;
  letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
  color: var(--color-text);
}

.doc-body h2 {
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-muted);
  letter-spacing: 0.02em;
  margin-top: 0;
  margin-bottom: 1.5rem;
}

/* First h2 = byline — keep it small and muted */
.doc-body > h2:first-of-type {
  font-size: 0.8rem;
  margin-bottom: 2rem;
}

.doc-body hr {
  border: none;
  border-top: 1px solid var(--color-rule);
  margin: 2rem 0;
}

.doc-body h2:not(:first-of-type) {
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  letter-spacing: 0;
}

.doc-body h3 {
  font-family: var(--font-ui);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text);
  margin-top: 1.75rem;
  margin-bottom: 0.5rem;
}

.doc-body p {
  margin-bottom: 1.25rem;
}

.doc-body ul, .doc-body ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
}

.doc-body li {
  margin-bottom: 0.35rem;
}

.doc-body strong {
  font-weight: 600;
}

.doc-body em {
  font-style: italic;
}

/* Tables */
.doc-body table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  display: block;
}

.doc-body th {
  background: var(--color-card-bg);
  font-weight: 600;
  text-align: left;
  padding: 0.6rem 0.9rem;
  border-bottom: 2px solid var(--color-rule);
  white-space: nowrap;
}

.doc-body td {
  padding: 0.55rem 0.9rem;
  border-bottom: 1px solid var(--color-rule);
  vertical-align: top;
}

.doc-body tr:last-child td {
  border-bottom: none;
}

/* Code */
.doc-body code {
  font-family: 'IBM Plex Mono', 'Courier New', monospace;
  font-size: 0.85em;
  background: var(--color-card-bg);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

.doc-body pre {
  background: var(--color-card-bg);
  padding: 1.25rem;
  overflow-x: auto;
  border-radius: 4px;
  margin: 1.5rem 0;
}

.doc-body pre code {
  background: none;
  padding: 0;
  font-size: 0.82rem;
  line-height: 1.6;
}

/* Blockquote */
.doc-body blockquote {
  border-left: 3px solid var(--color-accent);
  margin: 1.5rem 0;
  padding: 0.5rem 1.25rem;
  color: var(--color-muted);
  font-style: italic;
}

/* ---- DOCUMENT GRID (category + findings pages) ----------- */

.doc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1px;
  background: var(--color-rule);
  border: 1px solid var(--color-rule);
  margin-top: 2rem;
}

.doc-card {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 1.25rem 1.5rem;
  background: var(--color-bg);
  text-decoration: none;
  transition: background 0.12s;
}

.doc-card:hover {
  background: var(--color-card-hover);
  text-decoration: none;
}

.doc-card-title {
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.4;
}

.doc-card-excerpt {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  color: var(--color-muted);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.doc-card-date {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  color: var(--color-muted);
  letter-spacing: 0.03em;
  margin-top: auto;
}

/* ---- CATEGORY PAGE --------------------------------------- */

.category-header {
  margin-bottom: 0.5rem;
}

.category-section-label {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: 0.5rem;
}

.category-title {
  font-size: 2rem;
  font-weight: 500;
  line-height: 1.2;
  margin-bottom: 0.25rem;
}

.category-count {
  font-family: var(--font-ui);
  font-size: 0.82rem;
  color: var(--color-muted);
}

/* ---- SECTION LANDING (research / findings) --------------- */

.section-landing {}

.section-header {
  margin-bottom: 2.5rem;
  max-width: 52ch;
}

.section-header h1 {
  font-size: 2rem;
  font-weight: 500;
  line-height: 1.2;
  margin-bottom: 0.75rem;
}

.section-description {
  font-family: var(--font-ui);
  font-size: 0.9rem;
  color: var(--color-muted);
  line-height: 1.65;
}

.category-list {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--color-rule);
}

.category-item {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--color-rule);
  text-decoration: none;
  transition: padding-left 0.12s;
}

.category-item:hover {
  padding-left: 0.5rem;
  text-decoration: none;
}

.category-item-label {
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--color-text);
  font-weight: 500;
}

.category-item-count {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  color: var(--color-muted);
  flex-shrink: 0;
}

/* ---- HOMEPAGE -------------------------------------------- */

.home-page {
  max-width: 900px;
  padding-top: 5rem;
  padding-bottom: 5rem;
}

.home-hero {
  margin-bottom: 3.5rem;
  max-width: 60ch;
}

.home-wordmark {
  font-family: var(--font-body);
  font-size: 2.6rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 1.25rem;
  color: var(--color-text);
}

.home-description {
  font-family: var(--font-ui);
  font-size: 1rem;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 0.75rem;
}

.home-byline {
  font-family: var(--font-ui);
  font-size: 0.82rem;
  color: var(--color-muted);
}

.home-search {
  margin-bottom: 3.5rem;
  max-width: 640px;
}

.home-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--color-rule);
  border: 1px solid var(--color-rule);
  margin-bottom: 4rem;
}

.home-nav-tile {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding: 2rem;
  background: var(--color-bg);
  text-decoration: none;
  transition: background 0.12s;
}

.home-nav-tile:hover {
  background: var(--color-card-hover);
  text-decoration: none;
}

.tile-label {
  font-family: var(--font-ui);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.tile-title {
  font-family: var(--font-body);
  font-size: 1.3rem;
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.3;
}

.tile-description {
  font-family: var(--font-ui);
  font-size: 0.82rem;
  color: var(--color-muted);
  line-height: 1.65;
}

.tile-count {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  color: var(--color-muted);
  margin-top: auto;
  padding-top: 0.5rem;
}

.section-heading {
  font-family: var(--font-ui);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--color-rule);
}

.recent-list {
  display: flex;
  flex-direction: column;
}

.recent-item {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-rule);
  text-decoration: none;
  transition: padding-left 0.12s;
}

.recent-item:hover {
  padding-left: 0.5rem;
  text-decoration: none;
}

.recent-category {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-accent);
  flex-shrink: 0;
  min-width: 120px;
}

.recent-title {
  font-family: var(--font-body);
  font-size: 0.92rem;
  color: var(--color-text);
  line-height: 1.4;
}

/* ---- SEARCH PAGE ----------------------------------------- */

.search-page {
  max-width: 720px;
}

.search-title {
  font-size: 1.8rem;
  font-weight: 500;
  margin-bottom: 1.75rem;
}

/* Pagefind UI overrides */
:root {
  --pagefind-ui-scale: 0.9;
  --pagefind-ui-primary: var(--color-accent);
  --pagefind-ui-text: var(--color-text);
  --pagefind-ui-background: var(--color-bg);
  --pagefind-ui-border: var(--color-rule);
  --pagefind-ui-tag: var(--color-card-bg);
  --pagefind-ui-border-width: 1px;
  --pagefind-ui-border-radius: 3px;
  --pagefind-ui-font: var(--font-ui);
}

/* ---- FOOTER ---------------------------------------------- */

.site-footer {
  border-top: 1px solid var(--color-rule);
  padding: 1.25rem 2rem;
}

.footer-inner {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  color: var(--color-muted);
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

.footer-inner a {
  color: var(--color-muted);
  text-decoration: none;
}

.footer-inner a:hover {
  color: var(--color-accent);
  text-decoration: underline;
}

/* ---- RESPONSIVE ------------------------------------------ */

@media (max-width: 800px) {
  .page-layout {
    flex-direction: column;
    gap: 0;
    padding: 0 1.25rem;
  }

  .sidebar {
    width: 100%;
    padding-top: 1.5rem;
    padding-bottom: 0;
    border-bottom: 1px solid var(--color-rule);
    margin-bottom: 1.5rem;
  }

  .sidebar-section {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem 0.75rem;
    margin-bottom: 0.75rem;
  }

  .sidebar-heading {
    width: 100%;
  }

  .sidebar-link {
    border-left: none;
    padding-left: 0;
    margin-left: 0;
    padding: 0.2rem 0.6rem;
    background: var(--color-card-bg);
    border-radius: 3px;
  }

  .sidebar-link.active {
    background: var(--color-accent);
    color: white;
    border-left: none;
  }

  .home-nav {
    grid-template-columns: 1fr;
  }

  .home-wordmark {
    font-size: 2rem;
  }

  .home-page {
    padding-top: 2.5rem;
  }

  .doc-grid {
    grid-template-columns: 1fr;
  }

  .recent-item {
    flex-direction: column;
    gap: 0.2rem;
  }

  .recent-category {
    min-width: unset;
  }

  .site-nav {
    padding: 0 1.25rem;
    gap: 1rem;
  }
}

@media (max-width: 480px) {
  html { font-size: 16px; }
  .doc-body h1 { font-size: 1.5rem; }
  .home-wordmark { font-size: 1.75rem; }
}

/* ---- READ TIME & TOC ------------------------------------- */

.doc-meta-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.doc-read-time {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  color: var(--color-muted);
  letter-spacing: 0.03em;
}

.doc-toc {
  border: 1px solid var(--color-rule);
  border-left: 3px solid var(--color-rule);
  padding: 1rem 1.25rem;
  margin-bottom: 2rem;
  max-width: 52ch;
}

.doc-toc-label {
  font-family: var(--font-ui);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: 0.6rem;
}

.doc-toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
  counter-reset: toc-counter;
}

.doc-toc-item {
  counter-increment: toc-counter;
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.2rem 0;
}

.doc-toc-item::before {
  content: counter(toc-counter);
  font-family: var(--font-ui);
  font-size: 0.65rem;
  color: var(--color-muted);
  min-width: 1.2rem;
  flex-shrink: 0;
}

.doc-toc-item--sub {
  padding-left: 1.7rem;
  counter-increment: none;
}

.doc-toc-item--sub::before {
  content: '—';
  font-size: 0.6rem;
}

.doc-toc-link {
  font-family: var(--font-ui);
  font-size: 0.82rem;
  color: var(--color-muted);
  text-decoration: none;
  line-height: 1.4;
  transition: color 0.12s;
}

.doc-toc-link:hover {
  color: var(--color-accent);
  text-decoration: none;
}

/* ---- CHARTS ---------------------------------------------- */

.chart-container {
  margin: 1.75rem 0;
  padding: 1.25rem 1rem 1rem;
  background: var(--color-card-bg);
  border-left: 3px solid var(--color-accent);
}

.chart-container canvas {
  display: block;
  width: 100% !important;
}

.chart-replaced {
  display: none !important;
}

/* ---- STAT CALLOUTS --------------------------------------- */

.stat-callout {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin: 1.5rem 0;
  padding: 1rem 0;
  border-top: 1px solid var(--color-rule);
  border-bottom: 1px solid var(--color-rule);
}

.stat-callout-number {
  font-family: var(--font-ui);
  font-size: 2.4rem;
  font-weight: 600;
  color: var(--color-accent);
  line-height: 1;
  flex-shrink: 0;
  letter-spacing: -0.02em;
}

.stat-callout-context {
  font-family: var(--font-ui);
  font-size: 0.88rem;
  color: var(--color-muted);
  line-height: 1.55;
}

/* ---- AUDIO PLAYER ---------------------------------------- */

.audio-player {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--color-accent);
  color: #fff;
  z-index: 200;
  border-top: 1px solid rgba(255,255,255,0.15);
  box-shadow: 0 -2px 16px rgba(0,0,0,0.18);
  font-family: var(--font-ui);
}

.audio-player[hidden] { display: none; }

.audio-player-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 52px;
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.audio-player-left {
  display: flex;
  flex-direction: column;
  min-width: 0;
  flex: 1;
}

.audio-label {
  font-size: 0.6rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  opacity: 0.65;
  line-height: 1;
  margin-bottom: 2px;
}

.audio-title {
  font-size: 0.8rem;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  opacity: 0.9;
}

.audio-progress-track {
  width: 120px;
  height: 3px;
  background: rgba(255,255,255,0.25);
  border-radius: 2px;
  flex-shrink: 0;
}

.audio-progress-fill {
  height: 100%;
  background: #fff;
  border-radius: 2px;
  width: 0%;
  transition: width 0.3s ease;
}

.audio-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}

.audio-btn {
  background: none;
  border: none;
  color: #fff;
  cursor: pointer;
  font-size: 1rem;
  padding: 0.25rem 0.5rem;
  opacity: 0.85;
  transition: opacity 0.15s;
  line-height: 1;
}

.audio-btn:hover { opacity: 1; }

.audio-speeds {
  display: flex;
  gap: 0.25rem;
}

.audio-speed-btn {
  background: none;
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: 3px;
  color: rgba(255,255,255,0.7);
  cursor: pointer;
  font-family: var(--font-ui);
  font-size: 0.72rem;
  padding: 0.15rem 0.4rem;
  transition: all 0.12s;
}

.audio-speed-btn:hover {
  border-color: rgba(255,255,255,0.7);
  color: #fff;
}

.audio-speed-btn.is-active {
  background: rgba(255,255,255,0.2);
  border-color: rgba(255,255,255,0.7);
  color: #fff;
}

/* Listen button */
.listen-btn {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  color: var(--color-accent);
  background: none;
  border: 1px solid var(--color-rule);
  border-radius: 3px;
  padding: 0.3rem 0.75rem;
  cursor: pointer;
  margin-top: 0.75rem;
  display: inline-block;
  transition: border-color 0.15s, color 0.15s;
}

.listen-btn:hover {
  border-color: var(--color-accent);
  color: var(--color-accent-hover);
}

@media (max-width: 600px) {
  .audio-progress-track { display: none; }
  .audio-player-inner { gap: 0.75rem; padding: 0 1rem; }
  .audio-speeds { display: none; }
}