/* GenJAX Project Page — SIGGRAPH-Quality Academic Design
 * Dual-track navigation: Pedagogical (Tutorial) + Formal (PL Theory)
 * Typography: Source Serif Pro/Charter for body, Source Sans Pro for UI
 * Inspired by: ACM SIGGRAPH, POPL papers, tomasp.net/coeffects
 */

:root {
  color-scheme: light;
  /* Colors - Refined Academic Palette (ACM/SIGGRAPH inspired) */
  --color-text: #1a1a1a;
  --color-text-secondary: #333;
  --color-text-muted: #555;
  --color-text-light: #777;
  
  --color-link: #1a5276;
  --color-link-hover: #0d3246;
  --color-accent: #8b4513;
  --color-accent-light: #a0522d;
  
  --color-bg: #fff;
  --color-bg-warm: #fdfcfa;
  --color-bg-secondary: #f8f9fa;
  --color-bg-tertiary: #f0f1f2;
  
  --color-border: #d0d0d0;
  --color-border-light: #e5e5e5;
  --color-border-accent: #b8b8b8;
  
  /* Track colors - refined */
  --color-tutorial: #1e6f4e;
  --color-tutorial-bg: #e8f5ee;
  --color-tutorial-light: #d4ede0;
  --color-theory: #1a5276;
  --color-theory-bg: #e8f4f8;
  --color-theory-light: #d4e9f2;
  --color-all: #5d4e75;
  --color-all-bg: #f0edf5;
  
  /* Typography - Academic quality */
  --font-serif: "Source Serif 4", "Source Serif Pro", "Charter", "Georgia", "Times New Roman", serif;
  --font-sans: "Source Sans 3", "Source Sans Pro", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, sans-serif;
  --font-mono: "Source Code Pro", "SF Mono", "Monaco", "Inconsolata", "Fira Code", monospace;
  
  /* Spacing scale - compact but breathable */
  --space-xs: 0.15rem;
  --space-sm: 0.3rem;
  --space-md: 0.5rem;
  --space-lg: 0.75rem;
  --space-xl: 1rem;
  --space-2xl: 1.4rem;
  --space-3xl: 1.8rem;
  --space-4xl: 2.5rem;
  
  /* Layout */
  --max-width: 800px;
  --max-width-wide: 1000px;
  --sidebar-width: 220px;
  --nav-height: 52px;

  /* Figure sizing */
  --figure-max-width: 660px;
  --figure-max-width-wide: 780px;
  
  /* Shadows - subtle for academic feel */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 2px 6px rgba(0,0,0,0.05);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.08);
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16.5px;
  -webkit-text-size-adjust: 100%;
  background: var(--color-bg-warm);
  color-scheme: light;
}

body {
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg-warm);
  color-scheme: light;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

/* Typography Scale - Academic Hierarchy */
h1, h2, h3, h4, h5 {
  font-family: var(--font-sans);
  font-weight: 600;
  line-height: 1.35;
  margin: 0;
  color: var(--color-text);
}

h1 { 
  font-size: 2rem; 
  font-weight: 700;
  letter-spacing: -0.01em;
}

h2 {
  font-size: 1.4rem;
  margin-top: var(--space-xl);
  margin-bottom: var(--space-sm);
  padding-bottom: var(--space-xs);
  border-bottom: 1.5px solid var(--color-border);
}

h3 {
  font-size: 1.1rem;
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
  font-weight: 600;
}

h4 { 
  font-size: 0.98rem; 
  margin-top: var(--space-md);
  margin-bottom: var(--space-xs);
  font-weight: 600;
  color: var(--color-text-secondary);
}

p {
  margin: 0 0 var(--space-sm) 0;
  text-align: justify;
  hyphens: auto;
}

/* Academic-style paragraph spacing - no indent, space between */
p + p {
  text-indent: 0;
  margin-top: var(--space-xs);
}

/* Links */
a {
  color: var(--color-link);
  text-decoration: none;
  transition: color 0.15s ease;
}

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

/* Code - Inline */
code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: var(--color-bg-secondary);
  padding: 0.15em 0.35em;
  border-radius: 3px;
  color: var(--color-text);
  border: 1px solid var(--color-border-light);
}

pre {
  background: #fafafa;
  padding: var(--space-sm);
  border-radius: 4px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.6;
  border: 1px solid var(--color-border);
  margin: var(--space-sm) 0;
  text-align: left;
}

pre code {
  background: none;
  padding: 0;
  border: none;
  font-size: inherit;
}

pre code.hljs {
  background: transparent;
  padding: 0;
}

/* Layout Container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.container-wide {
  max-width: var(--max-width-wide);
}

/* Skip Link - Accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-link);
  color: white;
  padding: 8px;
  text-decoration: none;
  z-index: 1000;
}

.skip-link:focus {
  top: 0;
}

/* Header & Title Section */
.paper-header {
  text-align: center;
  padding: var(--space-lg) 0 var(--space-md);
  background: linear-gradient(to bottom, var(--color-bg), var(--color-bg-warm));
  border-bottom: 1px solid var(--color-border);
}

.paper-logo {
  display: block;
  max-width: 210px;
  height: auto;
  margin: 0 auto var(--space-xs);
}

.paper-header h1 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
  line-height: 1.25;
  letter-spacing: -0.01em;
  max-width: 850px;
  margin-left: auto;
  margin-right: auto;
}

.venue {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  color: var(--color-text-muted);
  font-style: italic;
  margin-top: var(--space-xs);
}

/* Authors Section */
.authors-section {
  text-align: center;
  padding: var(--space-sm) 0;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border-light);
}

.authors {
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: var(--space-xs);
}

.author-name {
  white-space: nowrap;
  font-family: var(--font-sans);
}

.author-name a {
  color: var(--color-text);
}

.author-name a:hover {
  color: var(--color-link);
}

.equal-contrib {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  font-style: italic;
  margin-left: var(--space-sm);
}

.affiliations {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-top: var(--space-xs);
}

/* Navigation - Sticky with blur */
.site-nav {
  position: sticky;
  top: 0;
  background: rgba(253, 252, 250, 0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
  padding: var(--space-xs) 0;
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.nav-brand {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-text);
}

.nav-brand a {
  color: inherit;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: var(--space-xs);
  font-family: var(--font-sans);
  font-size: 0.88rem;
}

.nav-links a {
  color: var(--color-text-secondary);
  padding: var(--space-xs) var(--space-sm);
  border-radius: 4px;
  transition: all 0.15s ease;
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--color-text);
  background: var(--color-bg-secondary);
}

.nav-links a.active {
  color: var(--color-link);
  font-weight: 500;
  background: rgba(26, 82, 118, 0.08);
}

/* Track Switcher - Dual Path Navigation */
.track-switcher-section {
  background: var(--color-bg);
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--color-border);
}

.track-switcher-section h2 {
  text-align: center;
  margin-top: 0;
  margin-bottom: var(--space-xs);
  border-bottom: none;
  font-size: 1.3rem;
}

.track-description {
  text-align: center;
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: 0.92rem;
  margin-bottom: var(--space-xs);
  max-width: 660px;
  margin-left: auto;
  margin-right: auto;
}

.track-switcher {
  display: flex;
  justify-content: center;
  gap: var(--space-xs);
  max-width: 680px;
  margin: 0 auto;
}

.track-btn {
  flex: 1;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  padding: var(--space-xs) var(--space-sm);
  border: 1.5px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text-secondary);
  cursor: pointer;
  border-radius: 6px;
  transition: all 0.2s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  text-align: center;
}

.track-btn:hover {
  border-color: var(--color-border-accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.track-btn.active {
  background: var(--color-bg);
  border-width: 1.5px;
}

.track-btn.active.tutorial-track {
  border-color: var(--color-tutorial);
  color: var(--color-tutorial);
  background: var(--color-tutorial-bg);
}

.track-btn.active.theory-track {
  border-color: var(--color-theory);
  color: var(--color-theory);
  background: var(--color-theory-bg);
}

.track-btn.active.all-track {
  border-color: var(--color-all);
  color: var(--color-all);
  background: var(--color-all-bg);
}

.track-btn .track-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-xs);
}

.track-btn .track-icon svg {
  width: 1.4rem;
  height: 1.4rem;
  display: block;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.track-btn .track-label {
  font-weight: 600;
  font-size: 1.05rem;
}

.track-btn .track-desc {
  font-size: 0.8rem;
  opacity: 0.9;
  line-height: 1.35;
}

/* Track Content Sections */
/* Default: show all content (no-JS fallback) */
.track-content {
  display: block;
}

/* JS-enabled: hide tracks, show only active */
.js-enabled .track-content {
  display: none;
}

.js-enabled .track-content.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

/* All mode: show both tracks (when JS is enabled) */
.js-enabled body.all-mode .track-content {
  display: block !important;
  animation: none;
}

body.all-mode .track-content + .track-content {
  margin-top: var(--space-2xl);
  padding-top: var(--space-2xl);
  border-top: 2px solid var(--color-border);
}

body.all-mode #track-tutorial::before {
  content: 'TUTORIAL TRACK';
  display: block;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-tutorial);
  letter-spacing: 0.08em;
  margin-bottom: var(--space-md);
}

body.all-mode #track-theory::before {
  content: 'THEORY TRACK';
  display: block;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-theory);
  letter-spacing: 0.08em;
  margin-bottom: var(--space-md);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Track indicator badges */
.track-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  padding: 3px 10px;
  border-radius: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.track-badge.tutorial {
  background: var(--color-tutorial-bg);
  color: var(--color-tutorial);
}

.track-badge.theory {
  background: var(--color-theory-bg);
  color: var(--color-theory);
}

/* Main Content Layout */
main {
  padding: var(--space-md) 0 var(--space-xl);
}

.main-content {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  grid-template-areas:
    "content"
    "sidebar";
  gap: var(--space-md);
}

@media (min-width: 1200px) {
  .main-content.with-sidebar {
    grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
    grid-template-areas: "sidebar content";
    gap: var(--space-lg);
  }
}

.content-area {
  grid-area: content;
  min-width: 0;
}

/* Section Styling */
section {
  margin-bottom: var(--space-lg);
}

section:first-child h2 {
  margin-top: 0;
}

/* Abstract - Prominent styling */
#abstract {
  background: var(--color-bg);
  padding: var(--space-md);
  border-radius: 6px;
  border: 1px solid var(--color-border);
  margin: var(--space-md) 0;
  box-shadow: var(--shadow-sm);
}

#abstract h2 {
  margin-top: 0;
  font-size: 1.2rem;
  border-bottom: none;
  margin-bottom: var(--space-xs);
}

.abstract {
  font-size: 0.98rem;
  line-height: 1.65;
}

.abstract p {
  margin: 0;
  text-align: justify;
}

/* Links Grid */
.links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-xs);
  margin: var(--space-xs) 0;
}

.link-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 5px;
  font-family: var(--font-sans);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-text);
  text-decoration: none;
  transition: all 0.15s ease;
}

.link-btn:hover {
  background: var(--color-bg-secondary);
  border-color: var(--color-link);
  color: var(--color-link);
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.link-btn svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  opacity: 0.8;
}

/* Video Link - Thumbnail with play button */
.video-link {
  display: block;
  position: relative;
  margin: var(--space-sm) 0;
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  text-decoration: none;
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.video-link:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
  text-decoration: none;
}

.video-thumbnail {
  display: block;
  width: 100%;
  height: auto;
}

.video-play-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -60%);
  width: 68px;
  height: 48px;
  opacity: 0.85;
  transition: opacity 0.15s ease;
}

.video-link:hover .video-play-btn {
  opacity: 1;
}

.video-play-btn svg {
  width: 100%;
  height: 100%;
}

.video-caption {
  display: block;
  padding: var(--space-sm) var(--space-md);
  background: var(--color-bg);
  font-family: var(--font-sans);
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  text-align: center;
}

/* Teaser Figure */
.teaser {
  margin: var(--space-lg) 0;
  text-align: center;
}

.teaser img {
  width: 100%;
  max-width: var(--figure-max-width);
  height: auto;
  display: block;
  margin: 0 auto;
  border-radius: 4px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--color-border);
}

.teaser .caption {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-top: var(--space-xs);
  max-width: var(--figure-max-width);
  margin-left: auto;
  margin-right: auto;
  line-height: 1.65;
  text-align: left;
  text-indent: 0;
}

.teaser .caption strong {
  font-weight: 600;
  color: var(--color-text);
}

/* Figures */
.figure {
  margin: var(--space-lg) auto;
  text-align: center;
  max-width: var(--figure-max-width);
}

.figure--wide {
  max-width: var(--figure-max-width-wide);
}

.figure--math {
  background: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: 6px;
  padding: var(--space-xs) var(--space-sm);
}

.figure--math .math-block {
  overflow-x: auto;
  padding: var(--space-xs) var(--space-sm) 0;
}

.figure--math .MathJax {
  font-size: 0.95em;
}

.figure img {
  width: 100%;
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
  border-radius: 3px;
  border: 1px solid var(--color-border);
}

.figure--wide img {
  max-width: 100%;
}

.figure-row {
  display: grid;
  gap: var(--space-xs);
  margin: var(--space-xs) 0;
}

.figure-row img {
  max-width: 100%;
}

.figure-row.two-col {
  grid-template-columns: repeat(2, 1fr);
}

.figure-row.three-col {
  grid-template-columns: repeat(3, 1fr);
}

@media (max-width: 768px) {
  .figure-row.two-col,
  .figure-row.three-col {
    grid-template-columns: 1fr;
  }
}

.fig-caption {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: var(--space-xs);
  max-width: var(--figure-max-width);
  margin-left: auto;
  margin-right: auto;
  line-height: 1.5;
  text-align: left;
  text-indent: 0;
}

.fig-caption strong {
  color: var(--color-text-secondary);
  font-weight: 600;
}

.figure--wide .fig-caption {
  max-width: var(--figure-max-width-wide);
}

/* Code Blocks - Enhanced */
.code-block {
  position: relative;
  margin: var(--space-xs) 0;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-bg-warm);
  box-shadow: var(--shadow-sm);
}

.code-block pre {
  margin: 0;
  border: none;
  border-radius: 0;
  background: var(--color-bg-warm);
  padding: var(--space-sm);
  white-space: pre-wrap;
  word-wrap: break-word;
}

.code-header {
  background: var(--color-bg-tertiary);
  padding: var(--space-xs) var(--space-sm);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--color-text-muted);
  font-weight: 500;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--color-border);
}

.code-header::before {
  content: '';
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--color-border-accent);
  margin-right: var(--space-sm);
  flex-shrink: 0;
}

.code-copy-btn {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 3px 8px;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  color: var(--color-text-muted);
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.15s ease, background 0.15s ease;
  line-height: 1.4;
  flex-shrink: 0;
  margin-left: auto;
}

/* Fallback: absolute positioning when no code-header */
.code-block > .code-copy-btn {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  z-index: 1;
}

.code-block:hover .code-copy-btn {
  opacity: 1;
}

.code-copy-btn:hover {
  background: var(--color-link);
  color: white;
  border-color: var(--color-link);
}

.code-copy-btn.copied {
  background: var(--color-tutorial);
  color: white;
  border-color: var(--color-tutorial);
  opacity: 1;
}

/* Math Blocks */
.math-block {
  overflow-x: auto;
  padding: var(--space-xs);
  margin: var(--space-xs) 0;
  text-align: center;
  background: var(--color-bg-secondary);
  border-radius: 4px;
}

.math-block::-webkit-scrollbar {
  height: 5px;
}

.math-block::-webkit-scrollbar-thumb {
  background: var(--color-border-accent);
  border-radius: 3px;
}

/* MathJax (SVG) Rendering */
mjx-container[jax="SVG"] {
  max-width: 100%;
}

mjx-container[jax="SVG"] svg {
  max-width: 100%;
  height: auto;
}

mjx-container[jax="SVG"][display="false"] {
  display: inline-block;
  vertical-align: -0.08em;
}

.math-block mjx-container[jax="SVG"][display="true"] {
  margin: 0 auto;
}

/* Info Boxes - Academic style */
.info-box {
  background: var(--color-bg-secondary);
  border-left: 3px solid var(--color-link);
  padding: var(--space-xs) var(--space-sm);
  margin: var(--space-xs) 0;
  border-radius: 0 5px 5px 0;
}

.info-box.warning {
  border-left-color: #c9a227;
  background: #fcf9f0;
}

.info-box.tip {
  border-left-color: var(--color-tutorial);
  background: var(--color-tutorial-bg);
}

.info-box.theorem {
  border-left-color: var(--color-theory);
  background: var(--color-theory-bg);
}

.info-box-title {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.92rem;
  margin-bottom: var(--space-xs);
  color: var(--color-text);
}

.roadmap-list {
  margin: var(--space-sm) 0 0 0;
  padding-left: 1.2rem;
}

.roadmap-list li {
  margin-bottom: var(--space-xs);
}

/* BibTeX */
.bibtex-container {
  position: relative;
  margin: var(--space-xs) 0;
}

.bibtex-block {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: var(--space-xs);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.55;
  overflow-x: auto;
  white-space: pre;
}

.copy-btn {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: var(--space-xs) var(--space-sm);
  font-family: var(--font-sans);
  font-size: 0.78rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.copy-btn:hover {
  background: var(--color-link);
  color: white;
  border-color: var(--color-link);
}

/* Lists */
ul, ol {
  padding-left: 1.6rem;
  margin: var(--space-xs) 0;
}

li {
  margin-bottom: var(--space-xs);
}

li p {
  text-indent: 0;
  margin-bottom: var(--space-xs);
}

/* Contribution List - Numbered */
.contributions {
  counter-reset: contribution;
  list-style: none;
  padding-left: 0;
}

.contributions li {
  position: relative;
  padding-left: 2.5rem;
  margin-bottom: var(--space-sm);
}

.contributions li::before {
  counter-increment: contribution;
  content: counter(contribution) ".";
  position: absolute;
  left: 0;
  font-weight: 700;
  color: var(--color-link);
  font-family: var(--font-sans);
  font-size: 1rem;
}

/* Tables - Academic style */
.table-wrapper {
  overflow-x: auto;
  margin: var(--space-sm) 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-sm) 0;
  font-size: 0.92rem;
  border: 1px solid var(--color-border);
}

th, td {
  padding: var(--space-sm) var(--space-md);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

th {
  font-family: var(--font-sans);
  font-weight: 600;
  background: var(--color-bg-secondary);
  border-bottom: 1.5px solid var(--color-border);
}

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

/* Sidebar TOC */
.sidebar {
  position: sticky;
  top: var(--nav-height);
  max-height: calc(100vh - var(--nav-height) - 2rem);
  overflow-y: auto;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  grid-area: sidebar;
}

@media (min-width: 1200px) {
  .sidebar {
    padding-right: var(--space-md);
    border-right: 1px solid var(--color-border);
  }
}

.toc-title {
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.72rem;
  margin-bottom: var(--space-sm);
}

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

.toc-nav li {
  margin-bottom: 2px;
}

.toc-nav a {
  display: block;
  padding: var(--space-xs) var(--space-sm);
  color: var(--color-text-secondary);
  border-radius: 4px;
  transition: all 0.15s ease;
  text-decoration: none;
  font-size: 0.82rem;
  line-height: 1.35;
}

.toc-nav a:hover {
  background: var(--color-bg-secondary);
  color: var(--color-text);
}

.toc-nav a.active {
  color: var(--color-link);
  font-weight: 500;
  background: rgba(26, 82, 118, 0.08);
}

.toc-nav .toc-h2 {
  font-weight: 500;
}

.toc-nav .toc-h3 {
  padding-left: 0.9rem;
  font-size: 0.77rem;
}

.toc-nav ul ul {
  padding-left: 0;
  margin-top: 2px;
}

.toc-nav ul ul li {
  margin-bottom: 0;
}

.js-enabled body[data-track="tutorial"] .toc-nav li[data-track="theory"],
.js-enabled body[data-track="theory"] .toc-nav li[data-track="tutorial"] {
  display: none;
}

/* Step/Tutorial styling */
.tutorial-step {
  margin: var(--space-lg) 0;
  padding: var(--space-md);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  box-shadow: var(--shadow-sm);
}

.tutorial-step h3 {
  margin-top: 0;
  color: var(--color-tutorial);
  border-bottom: 1px solid var(--color-tutorial-light);
  padding-bottom: var(--space-xs);
}

/* Theory section styling */
.theorem-box {
  background: var(--color-bg);
  border: 1px solid var(--color-theory-light);
  border-radius: 6px;
  padding: var(--space-xs);
  margin: var(--space-sm) 0;
}

.theorem-box .theorem-title {
  font-family: var(--font-sans);
  font-weight: 700;
  color: var(--color-theory);
  margin-bottom: var(--space-sm);
  font-size: 1.05rem;
}

/* Comparison table */
.comparison-table th:first-child,
.comparison-table td:first-child {
  width: 30%;
}

/* Artifact grid */
.artifact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-sm);
  margin: var(--space-sm) 0;
}

.artifact-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: var(--space-xs);
  text-align: center;
  transition: all 0.15s ease;
}

.artifact-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.artifact-card .artifact-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-sm);
}

.artifact-card .artifact-icon svg {
  width: 2rem;
  height: 2rem;
  display: block;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.artifact-card h4 {
  margin-top: 0;
  font-size: 0.95rem;
}

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

/* Tutorial progress/navigation */
.tutorial-progress {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--space-md);
  padding-top: var(--space-sm);
  border-top: 1px solid var(--color-border-light);
}

.tutorial-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-family: var(--font-sans);
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  text-decoration: none;
  cursor: pointer;
  transition: all 0.15s ease;
}

.tutorial-nav-btn:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text);
}

.tutorial-progress-dots {
  display: flex;
  gap: var(--space-xs);
}

.progress-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-border);
}

.progress-dot.completed {
  background: var(--color-tutorial);
}

.progress-dot.active {
  background: var(--color-tutorial);
  box-shadow: 0 0 0 3px var(--color-tutorial-bg);
}

/* Track widget */
.track-widget-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.track-widget {
  margin-top: var(--space-sm);
  padding-top: var(--space-xs);
  border-top: 1px solid var(--color-border);
}

.track-widget-btn {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xs);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
  text-align: left;
}

.track-widget-btn:hover {
  background: var(--color-bg-secondary);
}

.track-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

/* Definition list for concepts */
.concept-list {
  margin: var(--space-sm) 0;
}

.concept-list dt {
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--color-text);
  margin-top: var(--space-sm);
}

.concept-list dd {
  margin-left: 0;
  margin-top: var(--space-xs);
  color: var(--color-text-secondary);
}

/* Section anchors */
.section-anchor {
  opacity: 0;
  margin-left: var(--space-sm);
  color: var(--color-text-light);
  text-decoration: none;
  font-weight: 400;
  font-size: 0.85em;
}

h2:hover .section-anchor,
h3:hover .section-anchor {
  opacity: 1;
}

.section-anchor:hover {
  color: var(--color-link);
  text-decoration: none;
}

/* Footer */
.footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-lg) 0;
  margin-top: var(--space-xl);
  text-align: center;
  font-family: var(--font-sans);
  font-size: 0.88rem;
  color: var(--color-text-muted);
  background: var(--color-bg);
}

.footer a {
  color: var(--color-link);
}

.footer p {
  text-indent: 0;
  margin-bottom: var(--space-sm);
}

/* Print Styles */
@media print {
  .site-nav,
  .track-switcher,
  .sidebar,
  .copy-btn,
  .tutorial-progress,
  .track-widget {
    display: none !important;
  }
  
  body {
    font-size: 10.5pt;
    line-height: 1.5;
    background: white;
  }
  
  .track-content {
    display: block !important;
  }
  
  a {
    color: var(--color-text);
    text-decoration: none;
  }
  
  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
    color: var(--color-text-muted);
  }
}

/* Responsive — tablet */
@media (max-width: 1024px) {
  .container {
    padding: 0 var(--space-md);
  }

  .figure-row.two-col {
    gap: var(--space-sm);
  }

  .code-block pre {
    font-size: 0.75rem;
  }
}

/* Responsive — mobile */
@media (max-width: 768px) {
  html {
    font-size: 15px;
  }

  .container {
    padding: 0 var(--space-md);
  }

  .paper-header h1 {
    font-size: 1.6rem;
  }

  .track-switcher {
    flex-direction: column;
  }

  .track-btn {
    flex-direction: row;
    text-align: left;
    padding: var(--space-sm) var(--space-md);
  }

  .track-btn .track-icon {
    margin-bottom: 0;
    font-size: 1.2rem;
  }

  .track-btn .track-desc {
    display: none;
  }

  body.all-mode .track-content + .track-content {
    margin-top: var(--space-2xl);
    padding-top: var(--space-2xl);
  }

  .figure {
    margin: var(--space-md) 0;
  }

  .math-block {
    padding: var(--space-sm);
  }

  .math-block mjx-container[jax="SVG"] {
    font-size: 0.95em;
  }

  .authors {
    font-size: 0.9rem;
  }

  .nav-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-xs);
  }

  .code-block pre {
    font-size: 0.73rem;
    padding: var(--space-sm);
  }

  table {
    font-size: 0.85rem;
  }
}