/* === OccuBench - Analytical Observatory Design System === */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --bg: #0e1322;
  --bg-alt: #161b2b;
  --surface: #1a1f2f;
  --surface-high: #25293a;
  --surface-highest: #2f3445;
  --primary: #4d8eff;
  --primary-light: #adc6ff;
  --accent: #5de6ff;
  --tertiary: #4edea3;
  --amber: #f59e0b;
  --error: #ffb4ab;
  --on-surface: #dee1f7;
  --on-surface-variant: #c2c6d6;
  --outline: #8c909f;
  --outline-variant: #424754;
  --font-heading: 'Space Grotesk', 'Inter', sans-serif;
  --font-body: 'Inter', 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--on-surface);
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* === Reveal Animation === */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* === Layout === */
.container {
  max-width: 940px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

section {
  padding: 4.5rem 0;
}

section:nth-child(even) {
  background: var(--bg-alt);
}

/* === Hero === */
.hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 6rem 0 4rem;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  z-index: 0;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(14,19,34,0.82) 0%, rgba(14,19,34,0.92) 60%, rgba(14,19,34,1) 100%);
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 820px;
  padding: 0 1.5rem;
}

.hero h1 {
  font-family: var(--font-heading);
  font-size: 3.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #fff;
  margin-bottom: 0.5rem;
  line-height: 1.15;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--on-surface-variant);
  margin-bottom: 1.8rem;
  line-height: 1.5;
}

.hero-authors {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  margin-bottom: 0.8rem;
}

.author-chip {
  background: var(--surface-high);
  color: var(--on-surface-variant);
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 500;
}

.hero-affiliations {
  font-size: 0.85rem;
  color: var(--outline);
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.7rem 1.6rem;
  border-radius: 6px;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: all 0.2s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #001a42;
}
.btn-primary:hover {
  box-shadow: 0 0 20px rgba(77,142,255,0.3);
  transform: translateY(-1px);
}

/* === Section Headings === */
.section-heading {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 1.5rem;
  position: relative;
  padding-bottom: 0.75rem;
}
.section-heading::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), transparent);
  border-radius: 2px;
}

h3 {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--primary-light);
  margin-bottom: 1rem;
  margin-top: 2rem;
}

/* === Metric Cards === */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.2rem;
  margin-bottom: 2.5rem;
}

.metric-card {
  background: var(--surface);
  border-radius: 10px;
  padding: 1.8rem 1.2rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.metric-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent) 50%, transparent);
}

.metric-number {
  font-family: var(--font-heading);
  font-size: 2.8rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.1;
  text-shadow: 0 0 30px rgba(77,142,255,0.15);
}

.metric-label {
  font-size: 0.85rem;
  color: var(--on-surface-variant);
  margin-top: 0.5rem;
  font-weight: 500;
}

/* === Finding Cards === */
.findings-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.2rem;
}

.finding-card {
  background: var(--surface);
  border-radius: 10px;
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
}
.finding-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--primary) 50%, transparent);
}

.finding-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  margin-bottom: 0.7rem;
}

.finding-card:nth-child(1) .finding-badge { background: rgba(93,230,255,0.15); color: var(--accent); }
.finding-card:nth-child(2) .finding-badge { background: rgba(78,222,163,0.15); color: var(--tertiary); }
.finding-card:nth-child(3) .finding-badge { background: rgba(77,142,255,0.15); color: var(--primary); }
.finding-card:nth-child(4) .finding-badge { background: rgba(245,158,11,0.15); color: var(--amber); }

.finding-card h4 {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 0.5rem;
}

.finding-card p {
  font-size: 0.92rem;
  color: var(--on-surface-variant);
  line-height: 1.6;
}

/* === Cards Generic === */
.card {
  background: var(--surface);
  border-radius: 10px;
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent) 50%, transparent);
}

/* === Callout === */
.callout {
  background: var(--surface);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 1.2rem 1.5rem;
  margin: 1.5rem 0;
}

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

.callout ul {
  list-style: none;
  padding: 0;
}
.callout ul li {
  padding: 0.4rem 0;
  padding-left: 1.2rem;
  position: relative;
  color: var(--on-surface-variant);
}
.callout ul li::before {
  content: '?';
  position: absolute;
  left: 0;
  color: var(--accent);
}

/* === Limitation Cards === */
.limitation-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin: 1.5rem 0;
}

.limitation-card {
  background: var(--surface);
  border-radius: 8px;
  padding: 1.2rem;
}
.limitation-card h4 {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--primary-light);
  margin-bottom: 0.5rem;
}
.limitation-card p {
  font-size: 0.88rem;
  color: var(--on-surface-variant);
  line-height: 1.55;
}

/* === Component Cards (LES) === */
.components-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin: 1.5rem 0;
}

.component-card {
  background: var(--surface);
  border-radius: 8px;
  padding: 1.3rem;
}
.component-card h4 {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 0.4rem;
}
.component-card p {
  font-size: 0.9rem;
  color: var(--on-surface-variant);
  line-height: 1.55;
}

/* === Quality Badges === */
.quality-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 1rem 0;
}
.quality-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
  background: var(--surface-high);
  color: var(--on-surface-variant);
  border: 1px solid var(--outline-variant);
}

/* === Figures === */
figure {
  margin: 2rem 0;
  text-align: center;
}
figure img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  background: var(--surface);
  padding: 0.5rem;
}
figcaption {
  font-size: 0.85rem;
  color: var(--outline);
  margin-top: 0.75rem;
  font-style: italic;
  line-height: 1.5;
}

/* === Tables === */
.table-wrapper {
  overflow-x: auto;
  margin: 1.5rem 0;
  border-radius: 8px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  background: var(--surface);
}

thead {
  background: var(--surface-high);
}
thead th {
  padding: 0.75rem 0.6rem;
  text-align: center;
  font-family: var(--font-heading);
  font-weight: 600;
  color: var(--primary-light);
  font-size: 0.8rem;
  white-space: nowrap;
  border-bottom: 1px solid var(--outline-variant);
}
thead th:first-child {
  text-align: left;
  padding-left: 1rem;
}

tbody td {
  padding: 0.6rem;
  text-align: center;
  color: var(--on-surface-variant);
  border-bottom: 1px solid rgba(66,71,84,0.4);
  font-family: var(--font-mono);
  font-size: 0.82rem;
}
tbody td:first-child {
  text-align: left;
  padding-left: 1rem;
  font-family: var(--font-body);
  font-weight: 500;
  color: var(--on-surface);
}

tbody tr:hover {
  background: var(--surface-high);
}

td.best {
  color: var(--primary);
  font-weight: 700;
}

/* === Fault Cards === */
.fault-cards {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin: 1.5rem 0;
}

.fault-card {
  background: var(--surface);
  border-radius: 8px;
  padding: 1.2rem 1.5rem;
  border-left: 3px solid;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.fault-card.e0 { border-left-color: var(--tertiary); }
.fault-card.e1 { border-left-color: var(--amber); }
.fault-card.e2 { border-left-color: var(--error); }
.fault-card.e3 { border-left-color: var(--primary); }

.fault-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  white-space: nowrap;
}
.fault-card.e0 .fault-badge { background: rgba(78,222,163,0.15); color: var(--tertiary); }
.fault-card.e1 .fault-badge { background: rgba(245,158,11,0.15); color: var(--amber); }
.fault-card.e2 .fault-badge { background: rgba(255,180,171,0.15); color: var(--error); }
.fault-card.e3 .fault-badge { background: rgba(77,142,255,0.15); color: var(--primary); }

.fault-card h4 {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 0.3rem;
}
.fault-card p {
  font-size: 0.9rem;
  color: var(--on-surface-variant);
  line-height: 1.5;
}

/* === Details / Accordion === */
details {
  background: var(--surface);
  border-radius: 8px;
  margin: 1rem 0;
  overflow: hidden;
}
details summary {
  padding: 1rem 1.5rem;
  cursor: pointer;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1rem;
  color: var(--on-surface);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
details summary::before {
  content: '▶';
  font-size: 0.7rem;
  color: var(--primary);
  transition: transform 0.2s;
}
details[open] summary::before {
  transform: rotate(90deg);
}
details .details-content {
  padding: 0 1.5rem 1.5rem;
}

/* Case Study Status */
.case-status {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.15rem 0.5rem;
  border-radius: 3px;
  margin-left: 0.5rem;
}
.case-status.pass { background: rgba(78,222,163,0.15); color: var(--tertiary); }
.case-status.fail { background: rgba(255,180,171,0.15); color: var(--error); }
.case-status.partial { background: rgba(245,158,11,0.15); color: var(--amber); }

/* === Keywords === */
.keyword-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0;
}
.keyword-badge {
  background: var(--surface-high);
  color: var(--on-surface-variant);
  padding: 0.3rem 0.8rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 500;
  border: 1px solid var(--outline-variant);
  transition: border-color 0.2s;
}
.keyword-badge:hover {
  border-color: var(--primary);
}

/* === References === */
.references-list {
  padding-left: 1.5rem;
}
.references-list li {
  font-size: 0.82rem;
  color: var(--on-surface-variant);
  line-height: 1.6;
  margin-bottom: 0.4rem;
}

/* === Flecto Explanation UI === */
.flecto-note {
  background: var(--surface);
  border-left: 3px solid var(--primary);
  border-radius: 0 6px 6px 0;
  padding: 1rem 1.2rem;
  margin: 1.2rem 0;
  font-size: 0.92rem;
}
.flecto-note::before,
.flecto-callout::before,
.flecto-card::before,
.flecto-panel::before {
  content: '\1F916  AI explanation';
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  color: #60a5fa;
  letter-spacing: 0.06em;
  display: block;
  margin-bottom: 0.5em;
}
.flecto-callout {
  background: var(--surface-high);
  border-radius: 8px;
  padding: 1.2rem 1.5rem;
  margin: 1.5rem 0;
}
.flecto-card {
  background: var(--surface);
  border: 1px solid var(--outline-variant);
  border-radius: 10px;
  padding: 1.5rem;
  margin: 1.5rem 0;
  box-shadow: 0 2px 12px rgba(0,0,0,0.2);
}
.flecto-panel {
  background: var(--surface);
  border: 1px solid var(--outline-variant);
  border-radius: 10px;
  padding: 1.8rem;
  margin: 2rem 0;
  box-shadow: 0 4px 20px rgba(0,0,0,0.25);
}
.flecto-note h4, .flecto-callout h4, .flecto-card h4, .flecto-panel h4 {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 0.5rem;
  margin-top: 0;
}
.flecto-note p, .flecto-callout p, .flecto-card p, .flecto-panel p {
  color: var(--on-surface-variant);
  line-height: 1.6;
  margin-bottom: 0.5rem;
}
.flecto-card ul, .flecto-panel ul {
  padding-left: 1.2rem;
  margin: 0.5rem 0;
}
.flecto-card li, .flecto-panel li {
  color: var(--on-surface-variant);
  font-size: 0.92rem;
  margin-bottom: 0.3rem;
}

/* === Math (KaTeX) === */
.math-block {
  background: var(--surface);
  border-radius: 8px;
  padding: 1.2rem 1.5rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  text-align: center;
}
.katex { font-size: 1.1rem; }

/* === Mono highlight === */
code, .mono {
  font-family: var(--font-mono);
  font-size: 0.88em;
  color: var(--accent);
  background: rgba(93,230,255,0.08);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

/* === Responsive === */
@media (max-width: 768px) {
  .hero h1 { font-size: 2.2rem; }
  .hero-subtitle { font-size: 1rem; }
  .metrics-grid { grid-template-columns: repeat(2, 1fr); }
  .findings-grid { grid-template-columns: 1fr; }
  .limitation-cards { grid-template-columns: 1fr; }
  .components-grid { grid-template-columns: 1fr; }
  .section-heading { font-size: 1.6rem; }
  section { padding: 3rem 0; }
}

@media (max-width: 480px) {
  .metrics-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 1.8rem; }
  .metric-number { font-size: 2.2rem; }
}