/* ============================================================
   Precision Editing Studio — RefineAnything
   Design system: dark #13131b, violet #7c3aed, amber #ffb95f
   ============================================================ */

/* -- Google Fonts loaded in <head> -- */

/* ---- Custom Properties ---- */
:root {
  --bg: #13131b;
  --surface-low: #1b1b23;
  --surface: #1f1f27;
  --surface-high: #292932;
  --surface-highest: #34343d;
  --primary: #7c3aed;
  --primary-light: #d2bbff;
  --secondary: #ffb95f;
  --text-primary: #e4e1ed;
  --text-secondary: #ccc3d8;
  --outline: #4a4455;
  --radius: 4px;
  --font-heading: 'Space Grotesk', system-ui, sans-serif;
  --font-body: 'Inter', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Mono', monospace;
  --glow-violet: 0 0 24px rgba(124, 58, 237, 0.12);
  --section-pad: 64px;
  --container-max: 1120px;
  --card-gap: 32px;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; border-radius: var(--radius); }
a { color: var(--primary-light); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { font-family: var(--font-heading); line-height: 1.2; }

/* ---- Layout ---- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}
section { padding: var(--section-pad) 0; }
/* Section-specific backgrounds per design system */
#hero        { background: var(--bg); }
#abstract    { background: var(--surface-low); }
#introduction{ background: var(--bg); }
#related-work{ background: var(--surface-low); }
#method      { background: var(--bg); }
#experiments { background: var(--surface-low); }
#ablation    { background: var(--bg); }
#conclusion  { background: var(--surface-low); }
#references  { background: var(--bg); }

/* ---- Sticky Flecto Header ---- */
.site-header {
  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;
}
.site-header a { color: #8b8bcd; text-decoration: none; }
.site-header a:hover { color: var(--primary-light); }

/* ---- Section Headings ---- */
.section-label {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  margin-bottom: 8px;
}
h2.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 32px;
}
h3.subsection-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
}

/* ---- Hero ---- */
#hero {
  position: relative;
  min-height: 560px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--bg);
  padding: 80px 0 64px;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(19, 19, 27, 0.72);
}
/* Radial violet glow top-right */
#hero::after {
  content: '';
  position: absolute;
  top: -120px;
  right: -120px;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(124, 58, 237, 0.08) 0%, transparent 70%);
  pointer-events: none;
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 760px;
}
.hero-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  background: var(--surface-highest);
  color: var(--text-secondary);
  padding: 4px 12px;
  border-radius: var(--radius);
  margin-bottom: 20px;
  letter-spacing: 0.04em;
}
#hero h1 {
  font-size: clamp(1.75rem, 4vw, 3rem);
  font-weight: 700;
  color: #fff;
  margin-bottom: 16px;
  line-height: 1.15;
}
.hero-authors {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 28px;
}
.hero-metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 28px;
}
.metric-badge {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
}
.metric-value {
  font-family: var(--font-mono);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1;
}
.metric-label {
  font-family: var(--font-heading);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
}
.hero-teaser {
  font-size: 1rem;
  color: var(--text-primary);
  max-width: 680px;
  line-height: 1.7;
  margin-bottom: 32px;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 22px;
  border-radius: var(--radius);
  font-family: var(--font-heading);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: opacity 0.18s ease-out;
}
.btn:hover { opacity: 0.85; text-decoration: none; }
.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, #9d5ff3 100%);
  color: #fff;
}
.btn-ghost {
  background: transparent;
  color: var(--primary-light);
  border: 1px solid var(--outline);
}

/* ---- Abstract ---- */
.abstract-two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; }
@media (max-width: 768px) { .abstract-two-col { grid-template-columns: 1fr; } }
.abstract-text p { color: var(--text-primary); margin-bottom: 16px; }
.abstract-text p:last-child { margin-bottom: 0; }
.innovation-card {
  background: var(--surface-high);
  border-left: 4px solid var(--secondary);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--glow-violet);
}
.innovation-card .card-title {
  font-family: var(--font-heading);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--secondary);
  margin-bottom: 16px;
}
.innovation-card ul { list-style: none; padding: 0; }
.innovation-card li {
  color: var(--text-primary);
  padding: 6px 0;
  padding-left: 20px;
  position: relative;
  font-size: 0.9rem;
  line-height: 1.5;
}
.innovation-card li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--primary);
  font-weight: 700;
}

/* ---- Contribution Cards ---- */
.contributions-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--card-gap);
  margin-top: 32px;
}
@media (max-width: 900px) { .contributions-grid { grid-template-columns: 1fr; } }
.contribution-card {
  background: var(--surface-high);
  border-radius: var(--radius);
  padding: 24px;
  position: relative;
}
.contribution-card .card-number {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), #9d5ff3);
  color: #fff;
  padding: 3px 10px;
  border-radius: 2px;
  margin-bottom: 14px;
  letter-spacing: 0.06em;
}
.contribution-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text-primary);
}
.contribution-card p { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.6; }

/* ---- Pipeline Step Cards ---- */
.pipeline-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--card-gap);
  margin: 32px 0;
}
@media (max-width: 900px) { .pipeline-grid { grid-template-columns: 1fr; } }
.pipeline-card {
  background: var(--surface-high);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--glow-violet);
}
.pipeline-card .step-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), #5b21b6);
  color: #fff;
  padding: 3px 10px;
  border-radius: 2px;
  margin-bottom: 14px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.pipeline-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--primary-light);
}
.pipeline-card p { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.6; }

/* ---- Dataset Card ---- */
.dataset-card {
  background: var(--surface-high);
  border-radius: var(--radius);
  padding: 28px;
  margin-top: 32px;
}
.dataset-card .dataset-title {
  font-family: var(--font-heading);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--secondary);
  margin-bottom: 12px;
}
.dataset-splits {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 16px;
}
@media (max-width: 640px) { .dataset-splits { grid-template-columns: 1fr; } }
.dataset-split {
  background: var(--surface-highest);
  border-radius: var(--radius);
  padding: 16px;
}
.dataset-split .split-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 6px;
}
.dataset-split p { font-size: 0.875rem; color: var(--text-secondary); }
.pill {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  background: var(--secondary);
  color: #1a1a2e;
  padding: 2px 8px;
  border-radius: 12px;
  margin-right: 6px;
  vertical-align: middle;
}

/* ---- Ablation Cards ---- */
.ablation-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--card-gap);
  margin-bottom: 32px;
}
@media (max-width: 900px) { .ablation-grid { grid-template-columns: 1fr; } }
.ablation-card {
  background: var(--surface-high);
  border-radius: var(--radius);
  padding: 24px;
}
.ablation-card .component-badge {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  background: var(--secondary);
  color: #1a1a2e;
  padding: 3px 10px;
  border-radius: 2px;
  margin-bottom: 14px;
}
.ablation-card h3 { font-size: 1rem; font-weight: 700; color: var(--text-primary); margin-bottom: 10px; }
.ablation-card p { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.6; }

/* ---- Figures ---- */
.figure-container {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 20px;
  margin: 24px 0;
}
.figure-container img { width: 100%; height: auto; border-radius: var(--radius); }
.figure-container figcaption {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 12px;
  line-height: 1.5;
}
.figure-container figcaption strong { color: var(--primary-light); }
.figures-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin: 24px 0;
}
@media (max-width: 700px) { .figures-row { grid-template-columns: 1fr; } }

/* ---- Tables (image tables) ---- */
.table-container {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 20px;
  margin: 24px 0;
  overflow-x: auto;
}
.table-container img { width: 100%; height: auto; }
.table-container .table-caption {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 10px;
}
.table-container .table-caption strong { color: var(--primary-light); }

/* ---- References ---- */
#references { background: var(--bg); }
details > summary {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  cursor: pointer;
  padding: 12px 0;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
  user-select: none;
}
details > summary::-webkit-details-marker { display: none; }
details > summary::before {
  content: '▶';
  font-size: 0.75rem;
  color: var(--primary);
  transition: transform 0.18s ease-out;
  display: inline-block;
}
details[open] > summary::before { transform: rotate(90deg); }
.references-list {
  list-style: decimal;
  padding-left: 20px;
  margin-top: 16px;
}
.references-list li {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
  line-height: 1.5;
}

/* ---- Intro problem text ---- */
.problem-text {
  background: var(--surface-low);
  border-left: 4px solid var(--primary);
  padding: 24px;
  border-radius: var(--radius);
  margin-bottom: 32px;
}
.problem-text p { margin-bottom: 12px; }
.problem-text p:last-child { margin-bottom: 0; }

/* ---- flecto-note/callout/card/panel ---- */
.flecto-note,
.flecto-callout,
.flecto-card,
.flecto-panel {
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 20px 0;
  position: relative;
}
.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: var(--surface);
  border-left: 3px solid var(--primary);
  font-size: 0.9rem;
}
.flecto-callout {
  background: rgba(124, 58, 237, 0.08);
  border: 1px solid var(--outline);
}
.flecto-card {
  background: var(--surface-high);
  border: 1px solid var(--outline);
  box-shadow: var(--glow-violet);
}
.flecto-panel {
  background: var(--surface-high);
  border: 1px solid var(--primary);
  padding: 24px;
}

/* ---- Lead text ---- */
.lead {
  font-size: 1.05rem;
  color: var(--text-primary);
  max-width: 800px;
  margin-bottom: 24px;
}

/* ---- Reveal animation (class added by JS) ---- */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s ease-out, transform 0.4s ease-out;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  .reveal, .reveal.visible {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

/* ---- Footer ---- */
footer {
  background: var(--surface-low);
  padding: 32px 0;
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-secondary);
}
footer a { color: var(--primary-light); }

/* ---- Utility ---- */
.text-violet { color: var(--primary); }
.text-amber { color: var(--secondary); }
.mono { font-family: var(--font-mono); }
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}
