/* ============================================================
   RAGEN-2: Reasoning Collapse in Agentic RL
   Design System: Synthetica Research (Deep Space Scientific)
   ============================================================ */

:root {
  --primary: #adc6ff;
  --primary-container: #4d8eff;
  --secondary: #4fdbc8;
  --secondary-container: #04b4a2;
  --tertiary: #ffb690;
  --tertiary-container: #ec6a06;
  --background: #111319;
  --surface: #111319;
  --surface-lowest: #0c0e14;
  --surface-low: #191b22;
  --surface-container: #1e1f26;
  --surface-high: #282a30;
  --surface-highest: #33343b;
  --on-surface: #e2e2eb;
  --on-surface-variant: #c2c6d6;
  --outline: #8c909f;
  --outline-variant: #424754;
  --error: #ffb4ab;
  --radius: 4px;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--background);
  color: var(--on-surface);
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 1rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ── Flecto Nav ── */
.flecto-nav {
  position: sticky;
  top: 0;
  z-index: 9999;
  background: #1a1a2e;
  padding: 6px 16px;
  font-family: system-ui, sans-serif;
  font-size: 13px;
  border-bottom: 1px solid #333;
}
.flecto-nav a { color: #8b8bcd; text-decoration: none; }
.flecto-nav a:hover { color: var(--primary); }

/* ── Container ── */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Typography ── */
h1 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 2.8rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--on-surface);
}
h2 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--on-surface);
  border-left: 2px solid var(--primary-container);
  padding-left: 16px;
  margin-bottom: 32px;
}
h3 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--on-surface);
  margin-bottom: 12px;
}
h4 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 8px;
}

p { margin-bottom: 1.5rem; color: var(--on-surface); }
p:last-child { margin-bottom: 0; }

strong { color: var(--primary); font-weight: 600; }
em { color: var(--secondary); font-style: italic; }

/* ── Section ── */
section {
  padding: 80px 0;
}
section:nth-child(odd) { background: var(--surface); }
section:nth-child(even) { background: var(--surface-low); }

.section-header { margin-bottom: 48px; }
.section-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary-container);
  display: block;
  margin-bottom: 8px;
}

/* ── Hero ── */
#hero {
  position: relative;
  padding: 120px 0 80px;
  overflow: hidden;
  background: var(--surface-lowest);
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url('./assets/bg_hero.png');
  background-size: cover;
  background-position: center;
  z-index: 0;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(17,19,25,0.75) 0%, rgba(17,19,25,0.92) 100%);
  z-index: 1;
}
#hero .container {
  position: relative;
  z-index: 2;
}
.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}
.badge {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  font-weight: 500;
  padding: 4px 12px;
  border-radius: var(--radius);
  background: var(--surface-highest);
  color: var(--primary);
  border: 1px solid rgba(77,142,255,0.3);
  letter-spacing: 0.05em;
}
.badge-secondary { color: var(--secondary); border-color: rgba(79,219,200,0.3); }

.hero-title { margin-bottom: 16px; }
.hero-authors {
  font-size: 0.9rem;
  color: var(--on-surface-variant);
  margin-bottom: 32px;
  line-height: 1.6;
}

/* Hero Metrics */
.hero-metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 32px;
}
.metric-card {
  background: var(--surface-highest);
  border: 1px solid rgba(66,71,84,0.4);
  border-radius: var(--radius);
  padding: 20px 24px;
  filter: drop-shadow(0 0 8px rgba(77,142,255,0.3));
  text-align: center;
}
.metric-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.6rem;
  font-weight: 500;
  color: var(--primary);
  display: block;
  margin-bottom: 4px;
}
.metric-label {
  font-size: 0.75rem;
  color: var(--on-surface-variant);
  font-family: 'Space Grotesk', sans-serif;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* Hero Actions */
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  border-radius: var(--radius);
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
  cursor: pointer;
}
.btn-primary {
  background: var(--primary-container);
  color: #fff;
  border: none;
}
.btn-primary:hover {
  background: var(--primary);
  color: var(--surface-lowest);
  transform: translateY(-1px);
}
.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 1px solid var(--primary-container);
}
.btn-outline:hover {
  background: rgba(77,142,255,0.1);
  transform: translateY(-1px);
}

.hero-teaser {
  font-size: 1.05rem;
  color: var(--on-surface-variant);
  max-width: 680px;
  border-left: 2px solid var(--secondary);
  padding-left: 16px;
}

/* ── Cards ── */
.card {
  background: var(--surface-container);
  border: 1px solid rgba(66,71,84,0.15);
  border-radius: var(--radius);
  padding: 32px;
  transition: box-shadow 0.3s ease;
}
.card:hover {
  box-shadow: 0px 20px 40px rgba(173,198,255,0.08);
}
.card-elevated {
  background: var(--surface-high);
}

/* ── Grid Layouts ── */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  h1 { font-size: 2rem; }
}

/* ── Abstract Section ── */
.abstract-layout {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 48px;
  align-items: start;
}
@media (max-width: 900px) {
  .abstract-layout { grid-template-columns: 1fr; }
}
.contribution-list { list-style: none; padding: 0; }
.contribution-list li {
  padding: 12px 16px;
  background: var(--surface-container);
  border: 1px solid rgba(66,71,84,0.15);
  border-left: 3px solid var(--primary-container);
  border-radius: var(--radius);
  margin-bottom: 12px;
  font-size: 0.9rem;
  line-height: 1.5;
}
.contribution-list li:last-child { margin-bottom: 0; }

/* ── Callout Box ── */
.callout {
  background: var(--surface-high);
  border: 1px solid rgba(77,142,255,0.2);
  border-left: 3px solid var(--primary-container);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 24px 0;
}
.callout-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--primary-container);
  margin-bottom: 8px;
}

/* Research Questions */
.research-questions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 24px 0;
}
.rq-card {
  background: var(--surface-high);
  border: 1px solid rgba(77,142,255,0.2);
  border-radius: var(--radius);
  padding: 20px;
}
.rq-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--secondary);
  display: block;
  margin-bottom: 8px;
}
@media (max-width: 600px) {
  .research-questions { grid-template-columns: 1fr; }
}

/* ── Figures ── */
figure {
  margin: 32px 0;
  background: var(--surface-container);
  border: 1px solid rgba(66,71,84,0.15);
  border-radius: var(--radius);
  overflow: hidden;
}
figure img {
  width: 100%;
  height: auto;
  display: block;
}
figcaption {
  padding: 16px 20px;
  font-size: 0.875rem;
  color: var(--on-surface-variant);
  border-top: 1px solid rgba(66,71,84,0.15);
  line-height: 1.6;
}
figcaption strong { color: var(--primary); }

/* ── Math / Code ── */
.math-block {
  background: var(--surface-lowest);
  border: 1px solid rgba(66,71,84,0.3);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 16px 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.9rem;
  overflow-x: auto;
}
code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85em;
  background: var(--surface-highest);
  padding: 2px 6px;
  border-radius: 3px;
  color: var(--secondary);
}

/* ── Environments Grid ── */
.env-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin: 24px 0;
}
.env-card {
  background: var(--surface-container);
  border: 1px solid rgba(66,71,84,0.15);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}
.env-icon {
  font-size: 1.8rem;
  display: block;
  margin-bottom: 8px;
}
.env-name {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--primary);
  display: block;
  margin-bottom: 4px;
}
.env-type {
  font-size: 0.75rem;
  color: var(--on-surface-variant);
  font-family: 'JetBrains Mono', monospace;
}
@media (max-width: 768px) {
  .env-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ── Conclusion Cards ── */
.takeaway-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 32px;
}
.takeaway-card {
  background: var(--surface-container);
  border: 1px solid rgba(66,71,84,0.15);
  border-left: 3px solid var(--secondary);
  border-radius: var(--radius);
  padding: 28px;
}
.takeaway-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 2rem;
  font-weight: 700;
  color: var(--secondary);
  display: block;
  margin-bottom: 12px;
  opacity: 0.6;
}
@media (max-width: 900px) {
  .takeaway-grid { grid-template-columns: 1fr; }
}

/* ── Limitations ── */
.limitation-list {
  list-style: none;
  padding: 0;
  margin-top: 24px;
}
.limitation-list li {
  padding: 10px 16px;
  border-left: 2px solid var(--outline-variant);
  margin-bottom: 8px;
  color: var(--on-surface-variant);
  font-size: 0.9rem;
}

/* ── Accordion (Related Work / References) ── */
details {
  background: var(--surface-low);
  border: 1px solid rgba(66,71,84,0.2);
  border-radius: var(--radius);
  margin-bottom: 16px;
}
summary {
  padding: 16px 20px;
  cursor: pointer;
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 600;
  color: var(--on-surface);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
  user-select: none;
}
summary::before {
  content: '▶';
  font-size: 0.75rem;
  color: var(--primary-container);
  transition: transform 0.2s;
}
details[open] summary::before { transform: rotate(90deg); }
.details-content {
  padding: 16px 20px 24px;
  border-top: 1px solid rgba(66,71,84,0.15);
}

/* References */
.references-list {
  list-style: none;
  padding: 0;
  counter-reset: ref-counter;
}
.references-list li {
  counter-increment: ref-counter;
  padding: 8px 0 8px 40px;
  position: relative;
  font-size: 0.85rem;
  color: var(--on-surface-variant);
  border-bottom: 1px solid rgba(66,71,84,0.1);
  line-height: 1.5;
}
.references-list li::before {
  content: '[' counter(ref-counter) ']';
  position: absolute;
  left: 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--primary-container);
  top: 10px;
}

/* ── Related Work Groups ── */
.related-group { margin-bottom: 28px; }
.related-group h3 { color: var(--secondary); font-size: 1rem; margin-bottom: 8px; }

/* ── Flecto Explanation UI ── */
.flecto-note,
.flecto-callout,
.flecto-card,
.flecto-panel {
  position: relative;
  border-radius: var(--radius);
  margin: 20px 0;
}
.flecto-note::before,
.flecto-callout::before,
.flecto-card::before,
.flecto-panel::before {
  content: '🤖 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-note {
  background: rgba(77,142,255,0.06);
  border-left: 2px solid var(--primary-container);
  padding: 12px 16px;
  font-size: 0.9rem;
  color: var(--on-surface-variant);
}
.flecto-callout {
  background: rgba(79,219,200,0.08);
  border: 1px solid rgba(79,219,200,0.3);
  padding: 16px 20px;
}
.flecto-card {
  background: var(--surface-container);
  border: 1px solid rgba(66,71,84,0.2);
  box-shadow: 0 4px 16px rgba(0,0,0,0.3);
  padding: 20px 24px;
}
.flecto-panel {
  background: var(--surface-high);
  border: 1px solid rgba(66,71,84,0.3);
  padding: 24px 28px;
}

/* ── Scroll Reveal ── */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: none;
}
@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

/* ── Divider ── */
.divider {
  border: none;
  border-top: 1px solid var(--outline-variant);
  margin: 32px 0;
  opacity: 0.3;
}

/* ── Table ── */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  margin: 16px 0;
}
.data-table th {
  background: var(--surface-high);
  color: var(--primary);
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 10px 12px;
  border-bottom: 1px solid var(--outline-variant);
  text-align: left;
}
.data-table td {
  padding: 8px 12px;
  border-bottom: 1px solid rgba(66,71,84,0.15);
  color: var(--on-surface-variant);
}
.data-table tr:hover td { background: rgba(77,142,255,0.04); }

/* ── Subsection spacing ── */
.subsection { margin-bottom: 56px; }
.subsection:last-child { margin-bottom: 0; }

/* ── Algorithm box ── */
.algorithm-box {
  background: var(--surface-lowest);
  border: 1px solid rgba(77,142,255,0.2);
  border-left: 3px solid var(--primary-container);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 20px 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
}
.algorithm-title {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 12px;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.algorithm-step {
  padding: 4px 0;
  color: var(--on-surface-variant);
}
.algorithm-step .step-num {
  color: var(--secondary);
  margin-right: 8px;
}