/* ════════════════════════════════════════════════════════════════
   Mastering Causal Metrics — Custom Stylesheet
   Color palette:
     CausalBlue  #2563eb (light) / #38bdf8 (dark)
     MethodPurple #7c3aed (light) / #a78bfa (dark)
     EvidenceGreen #059669 (light) / #34d399 (dark)
     DeepSlate    #0f172a (dark bg)
   ════════════════════════════════════════════════════════════════ */

/* Load Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* Force page-level TOC list to always be visible (desktop) */
@media (min-width: 992px) {
  #TOC ul {
    display: block !important;
  }
}

/* Left-align Colab badge and hide its auto-generated figcaption */
.quarto-figure-center:has(img[src*="colab-badge"]) {
  text-align: left !important;
}
.quarto-figure-center:has(img[src*="colab-badge"]) .figure {
  text-align: left !important;
  display: inline !important;
}
.quarto-figure-center:has(img[src*="colab-badge"]) figcaption {
  display: none !important;
}
img[src*="colab-badge"] {
  margin: 0 !important;
}

/* Hide "Preface" H1 title on landing page */
#preface > h1 {
  display: none;
}

/* Hide breadcrumb navigation */
.quarto-page-breadcrumbs {
  display: none !important;
}

/* Full-width visual summary images */
img[src*="visual_summary"] {
  width: 100% !important;
  border: 2px solid #2563eb;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  display: block;
  margin: 1rem auto;
}

/* ── Heading colors ── */

h1 {
  color: #2563eb !important;
}

h2 {
  color: #7c3aed !important;
  border-left: 4px solid #7c3aed;
  padding-left: 0.75rem;
}

h3 {
  color: #059669 !important;
}

h4 {
  color: #0f172a !important;
}

/* ── Code blocks ── */

div.sourceCode {
  background-color: #f7fafc !important;
  border-left: 3px solid #2563eb !important;
  border-radius: 4px;
}

/* ── Inline code ── */

code {
  background-color: #edf2f7;
  padding: 0.15em 0.4em;
  border-radius: 3px;
  color: #2d3748;
}

pre code {
  background-color: transparent;
  padding: 0;
  color: inherit;
}

/* ── Tables ── */

table thead th {
  background-color: #f7fafc !important;
  border-bottom: 2px solid #2563eb !important;
}

table tbody tr:nth-child(even) {
  background-color: #f7fafc;
}

/* ── Blockquotes / Key Concepts ── */

blockquote {
  border-left: 4px solid #7c3aed !important;
  background-color: #f5f3ff;
  padding: 1rem 1.25rem;
  border-radius: 4px;
  margin: 1rem 0;
  color: #1a365d !important;
}

blockquote strong {
  color: #7c3aed;
  font-size: 1.05em;
}

/* ── List markers ── */

ul li::marker {
  color: #2563eb;
}

ol li::marker {
  color: #7c3aed;
  font-weight: 600;
}

/* ── Links ── */

a {
  color: #2563eb;
}

a:hover {
  color: #7c3aed;
}

/* ── Chapter resource buttons ── */

.chapter-resources {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0.75rem 0;
}

.resource-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.35rem 0.75rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 500;
  text-decoration: none !important;
  background-color: #f0f4f8;
  color: #2563eb !important;
  border: 1px solid #d0dce8;
  transition: all 0.2s;
}

.resource-btn:hover {
  background-color: #2563eb;
  color: white !important;
  border-color: #2563eb;
  text-decoration: none !important;
}

/* ── Output images ── */

.cell-output img {
  display: block;
  margin: 1rem auto;
}

.hidden {
  display: none !important;
}

/* ── Book cover image in right sidebar ── */

#toc-cover-image {
  text-align: center;
  padding: 0 0.5rem 1rem 0.5rem;
  margin-bottom: 0.5rem;
  border-bottom: 1px solid #e2e8f0;
}

#toc-cover-image img {
  max-width: 100%;
  border-radius: 6px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

/* ── Left Sidebar Navigation ── */

.sidebar-item-section > .sidebar-item-container > .sidebar-item-text {
  color: #7c3aed !important;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-size: 0.85rem;
  padding-bottom: 0.25rem;
  border-bottom: 1.5px solid rgba(124, 58, 237, 0.3);
}

.sidebar-section .sidebar-item-text .chapter-title {
  color: #2563eb !important;
}

#quarto-sidebar .sidebar-item:not(.sidebar-item-section) > .sidebar-item-container > .sidebar-item-text .menu-text {
  color: #2563eb !important;
}

.sidebar-item-text.sidebar-link.active .chapter-title,
.sidebar-item-text.sidebar-link.active .menu-text {
  font-weight: 700;
}

.sidebar-link.active {
  background-color: rgba(37, 99, 235, 0.1) !important;
  border-left: 3px solid #2563eb;
  padding-left: 0.5rem;
}

.sidebar-link {
  transition: all 0.2s;
}

.sidebar-link:hover {
  background-color: rgba(37, 99, 235, 0.05) !important;
}

/* ── Right Sidebar TOC ── */

#TOC {
  background: linear-gradient(180deg, #f7fafc 0%, #ffffff 100%);
  border-radius: 8px;
  border: 1px solid #e2e8f0;
  padding: 0.75rem;
}

#TOC h2 {
  color: #7c3aed !important;
  font-size: 0.95rem;
  font-weight: 700;
  border-left: none;
  border-bottom: 2px solid #2563eb;
  padding-left: 0;
  padding-bottom: 0.4rem;
  margin-bottom: 0.75rem;
}

/* Top-level TOC items (## sections) — full weight */
#TOC > ul > li > a.nav-link {
  font-weight: 600;
  font-size: 0.9rem;
}

/* Nested TOC items (### subsections) — indented, smaller, lighter */
#TOC > ul > li > ul {
  padding-left: 0.75rem;
  border-left: 1px solid #e2e8f0;
  margin-left: 0.5rem;
}

#TOC > ul > li > ul > li > a.nav-link {
  font-weight: 400;
  font-size: 0.82rem;
  color: #64748b !important;
}

#TOC a.nav-link {
  color: #2d3748 !important;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  border-left: 3px solid transparent;
  transition: all 0.2s;
}

#TOC a.nav-link:hover {
  background-color: rgba(37, 99, 235, 0.08);
  color: #2563eb !important;
}

#TOC a.nav-link.active {
  color: #2563eb !important;
  font-weight: 600;
  background-color: rgba(37, 99, 235, 0.1);
  border-left: 3px solid #2563eb;
}

/* ── Page Navigation ── */

nav.page-navigation {
  border-top: 2px solid #2563eb;
  padding-top: 1.5rem;
  margin-top: 3rem;
}

nav.page-navigation .nav-page a {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  background-color: #f7fafc;
  border: 1px solid #d0dce8;
  border-radius: 6px;
  transition: all 0.3s;
  text-decoration: none !important;
  color: #2563eb !important;
  font-weight: 500;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

nav.page-navigation .nav-page a:hover {
  background-color: #2563eb;
  color: white !important;
  border-color: #2563eb;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
  transform: translateY(-1px);
}

/* ── Title Block ── */

header#title-block-header {
  background: linear-gradient(135deg, #f7fafc 0%, #eef2ff 100%);
  border-bottom: 3px solid #2563eb;
  padding: 1.5rem;
  margin-bottom: 2rem;
  border-radius: 0 0 8px 8px;
}

.quarto-title-meta-heading {
  color: #7c3aed !important;
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.quarto-title-meta-contents {
  color: #2d3748;
}

/* ── Code Output Blocks ── */

.cell-output-stdout pre,
.cell-output-display pre {
  border-left: 3px solid #7c3aed !important;
  background-color: #f5f3ff !important;
  border-radius: 4px;
  padding: 0.75rem;
}

.cell-output-display .dataframe {
  border-left: 3px solid #7c3aed;
}

/* ── Visual Summary Hover Effect ── */

img[src*="visual_summary"] {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

img[src*="visual_summary"]:hover {
  transform: scale(1.01);
  box-shadow: 0 8px 16px rgba(37, 99, 235, 0.2);
}

/* ── Search Box ── */

.aa-Autocomplete .aa-Form {
  border: 2px solid #d0dce8 !important;
  border-radius: 6px !important;
  transition: all 0.2s;
}

.aa-Autocomplete .aa-Form:focus-within {
  border-color: #2563eb !important;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15) !important;
}

/* ── Content Link Underlines ── */

main a:not(.nav-link):not(.sidebar-link):not(.resource-btn):not(.quarto-figure a) {
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: all 0.2s;
}

main a:not(.nav-link):not(.sidebar-link):not(.resource-btn):not(.quarto-figure a):hover {
  border-bottom-color: #7c3aed;
}

/* ── List Spacing ── */

main li {
  margin-bottom: 0.35rem;
}

/* Hide scrollbar tracks on sidebars */
#quarto-sidebar,
#quarto-margin-sidebar,
#TOC,
.mobile-toc-content {
  scrollbar-width: none;
  -ms-overflow-style: none;
}

#quarto-sidebar::-webkit-scrollbar,
#quarto-margin-sidebar::-webkit-scrollbar,
#TOC::-webkit-scrollbar,
.mobile-toc-content::-webkit-scrollbar {
  display: none;
}


/* ════════════════════════════════════════════════════════════════
   DARK MODE OVERRIDES
   Cyan (#38bdf8) for interactive/primary, Purple (#a78bfa) for
   structural emphasis. Navy background (#0f172a).
   ════════════════════════════════════════════════════════════════ */

.quarto-dark {
  --bs-body-bg: #0f172a !important;
  background-color: #0f172a !important;
}

/* ── Headings ── */

.quarto-dark h1 {
  color: #38bdf8 !important;
}

.quarto-dark h2 {
  color: #a78bfa !important;
  border-left-color: #a78bfa;
}

.quarto-dark h3 {
  color: #34d399 !important;
}

.quarto-dark h4 {
  color: #94a3b8 !important;
}

.quarto-dark h5,
.quarto-dark h6 {
  color: #94a3b8 !important;
}

/* ── Code blocks ── */

.quarto-dark div.sourceCode {
  background-color: #1e293b !important;
}

.quarto-dark div.sourceCode pre {
  color: #e2e8f0;
}

/* ── Inline code ── */

.quarto-dark code {
  background-color: rgba(255, 255, 255, 0.1);
  color: #e2e8f0;
}

.quarto-dark pre code {
  background-color: transparent;
  color: inherit;
}

/* ── Tables ── */

.quarto-dark table {
  color: #e2e8f0;
}

.quarto-dark table thead th {
  background-color: rgba(56, 189, 248, 0.1) !important;
  color: #f1f5f9 !important;
  border-bottom-color: #38bdf8 !important;
}

.quarto-dark table tbody tr:nth-child(even) {
  background-color: rgba(255, 255, 255, 0.03);
}

/* ── Blockquotes ── */

.quarto-dark blockquote {
  background-color: rgba(167, 139, 250, 0.08);
  border-left-color: #a78bfa !important;
  color: #e2e8f0 !important;
}

.quarto-dark blockquote strong {
  color: #a78bfa;
}

/* ── Links ── */

.quarto-dark a {
  color: #38bdf8;
}

.quarto-dark a:hover {
  color: #a78bfa;
}

.quarto-dark main a:not(.nav-link):not(.sidebar-link):not(.resource-btn):not(.quarto-figure a):hover {
  border-bottom-color: #a78bfa;
}

/* ── List markers ── */

.quarto-dark ul li::marker {
  color: #38bdf8;
}

.quarto-dark ol li::marker {
  color: #a78bfa;
}

/* ── Resource buttons ── */

.quarto-dark .resource-btn {
  background-color: rgba(255, 255, 255, 0.08);
  color: #38bdf8 !important;
  border-color: rgba(255, 255, 255, 0.15);
}

.quarto-dark .resource-btn:hover {
  background-color: #38bdf8;
  color: #0f172a !important;
  border-color: #38bdf8;
}

/* ── Cover image separator ── */

.quarto-dark #toc-cover-image {
  border-bottom-color: rgba(255, 255, 255, 0.15);
}

/* ── Left Sidebar ── */

.quarto-dark #quarto-sidebar {
  background-color: #0f172a !important;
}

.quarto-dark .sidebar-item-section > .sidebar-item-container > .sidebar-item-text {
  color: #a78bfa !important;
  border-bottom-color: rgba(167, 139, 250, 0.35);
}

.quarto-dark .sidebar-section .sidebar-item-text .chapter-title {
  color: #38bdf8 !important;
}

.quarto-dark #quarto-sidebar .sidebar-item:not(.sidebar-item-section) > .sidebar-item-container > .sidebar-item-text .menu-text {
  color: #38bdf8 !important;
}

.quarto-dark .sidebar-link.active {
  background-color: rgba(56, 189, 248, 0.1) !important;
  border-left-color: #38bdf8;
}

.quarto-dark .sidebar-link:hover {
  background-color: rgba(56, 189, 248, 0.06) !important;
}

/* ── Right Sidebar TOC ── */

.quarto-dark #TOC {
  background: #0f172a;
  border-color: rgba(255, 255, 255, 0.1);
}

.quarto-dark #TOC h2 {
  color: #a78bfa !important;
  border-bottom-color: #38bdf8;
}

/* Nested TOC items — dark mode indent line */
.quarto-dark #TOC > ul > li > ul {
  border-left-color: rgba(255, 255, 255, 0.1);
}

.quarto-dark #TOC > ul > li > ul > li > a.nav-link {
  color: #94a3b8 !important;
}

.quarto-dark #TOC a.nav-link {
  color: #cbd5e0 !important;
}

.quarto-dark #TOC a.nav-link:hover {
  background-color: rgba(56, 189, 248, 0.08);
  color: #38bdf8 !important;
}

.quarto-dark #TOC a.nav-link.active {
  color: #38bdf8 !important;
  background-color: rgba(56, 189, 248, 0.1);
  border-left-color: #38bdf8;
}

/* ── Page navigation ── */

.quarto-dark nav.page-navigation {
  border-top-color: rgba(255, 255, 255, 0.1);
}

.quarto-dark nav.page-navigation .nav-page a {
  background-color: rgba(255, 255, 255, 0.05);
  border-color: rgba(255, 255, 255, 0.15);
  color: #38bdf8 !important;
}

.quarto-dark nav.page-navigation .nav-page a:hover {
  background-color: #38bdf8;
  color: #0f172a !important;
  border-color: #38bdf8;
}

/* ── Title block ── */

.quarto-dark header#title-block-header {
  background: rgba(56, 189, 248, 0.05);
  border-bottom-color: #38bdf8;
}

.quarto-dark .subtitle {
  color: #e2e8f0 !important;
}

.quarto-dark .quarto-title-meta-heading {
  color: #a78bfa !important;
}

.quarto-dark .quarto-title-meta-contents {
  color: #cbd5e0;
}

/* ── Code output blocks ── */

.quarto-dark .cell-output-stdout pre,
.quarto-dark .cell-output-display pre {
  background-color: #1e293b !important;
  border-left-color: #a78bfa !important;
}

.quarto-dark .cell-output-display .dataframe {
  border-left-color: #a78bfa;
}

/* ── Visual summary image ── */

.quarto-dark img[src*="visual_summary"] {
  border-color: #38bdf8;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

/* ── Header bar ── */

.quarto-dark #quarto-header {
  background-color: #0b0f1f !important;
}

/* ── Search box ── */

.quarto-dark .aa-Autocomplete .aa-Form {
  border-color: rgba(255, 255, 255, 0.15) !important;
}

.quarto-dark .aa-Autocomplete .aa-Form:focus-within {
  border-color: #38bdf8 !important;
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15) !important;
}


/* ════════════════════════════════════════════════════════════════
   MOBILE RIGHT-PANEL TOC
   ════════════════════════════════════════════════════════════════ */

.mobile-toc-nav-btn {
  margin-left: 0.25rem;
  -webkit-tap-highlight-color: transparent;
}

.mobile-toc-nav-btn i {
  font-size: 1.1rem;
}

@media (min-width: 992px) {
  .mobile-toc-nav-btn {
    display: none !important;
  }
}

.mobile-toc-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1055;
  background: rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
}

.mobile-toc-overlay.active {
  opacity: 1;
  visibility: visible;
}

.mobile-toc-panel {
  position: fixed;
  top: 0;
  right: 0;
  width: 300px;
  max-width: 85vw;
  height: 100%;
  z-index: 1060;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  transform: translateX(100%);
  transition: transform 0.3s ease;
  background: #ffffff;
  border-left: 2px solid #2563eb;
  color: #2d3748;
}

.mobile-toc-panel.active {
  transform: translateX(0);
}

.quarto-dark .mobile-toc-panel {
  background: #0f172a;
  border-left-color: #38bdf8;
  color: #e2e8f0;
}

.mobile-toc-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid #e2e8f0;
  position: sticky;
  top: 0;
  background: inherit;
  z-index: 1;
}

.quarto-dark .mobile-toc-header {
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

.mobile-toc-header h3 {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  color: #2563eb !important;
  border-left: none;
}

.quarto-dark .mobile-toc-header h3 {
  color: #38bdf8 !important;
}

.mobile-toc-close {
  background: none;
  border: none;
  color: #94a3b8;
  font-size: 1.75rem;
  cursor: pointer;
  padding: 0;
  line-height: 1;
  transition: color 0.15s;
  -webkit-tap-highlight-color: transparent;
}

.mobile-toc-close:hover {
  color: #2563eb;
}

.quarto-dark .mobile-toc-close:hover {
  color: #38bdf8;
}

.mobile-toc-content {
  padding: 0.75rem 1rem;
}

.mobile-toc-content ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.mobile-toc-content li {
  margin: 0;
}

.mobile-toc-content a {
  display: block;
  padding: 0.5rem 0.75rem;
  text-decoration: none !important;
  border-radius: 4px;
  border-left: 3px solid transparent;
  font-size: 0.9rem;
  transition: all 0.15s;
  color: #4a5568 !important;
}

.mobile-toc-content a:hover,
.mobile-toc-content a.active {
  background-color: rgba(37, 99, 235, 0.08);
  color: #2563eb !important;
  border-left-color: #2563eb;
}

.quarto-dark .mobile-toc-content a {
  color: #cbd5e0 !important;
}

.quarto-dark .mobile-toc-content a:hover,
.quarto-dark .mobile-toc-content a.active {
  background-color: rgba(56, 189, 248, 0.08);
  color: #38bdf8 !important;
  border-left-color: #38bdf8;
}

.mobile-toc-content ul ul {
  padding-left: 1rem;
}

.mobile-toc-content ul ul a {
  font-size: 0.85rem;
  padding: 0.35rem 0.75rem;
}


/* ════════════════════════════════════════════════════════════════
   SIDEBAR TOGGLE BUTTONS (desktop only)
   ════════════════════════════════════════════════════════════════ */

.sidebar-toggle {
  display: none;
}

@media (min-width: 992px) {
  .sidebar-toggle {
    position: fixed;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1040;
    width: 24px;
    height: 48px;
    border: 1px solid rgba(0, 0, 0, 0.15);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    opacity: 0.4;
    transition: opacity 0.2s;
    padding: 0;
    background: #f8f9fa;
    color: #495057;
  }

  .sidebar-toggle:hover {
    opacity: 1;
  }

  .sidebar-toggle-left {
    left: 0;
    border-radius: 0 6px 6px 0;
    border-left: none;
  }

  .sidebar-toggle-right {
    right: 0;
    border-radius: 6px 0 0 6px;
    border-right: none;
  }

  .quarto-dark .sidebar-toggle {
    background: #0f172a;
    color: #cbd5e0;
    border-color: rgba(255, 255, 255, 0.15);
  }

  body.left-collapsed #quarto-sidebar {
    display: none !important;
  }

  body.toc-collapsed #quarto-margin-sidebar {
    display: none !important;
  }

  body.left-collapsed .sidebar-toggle-left i {
    transform: scaleX(-1);
  }

  body.toc-collapsed .sidebar-toggle-right i {
    transform: scaleX(-1);
  }
}