/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #F0EFF5;
  --surface: #FFFFFF;
  --primary: #2E1065;
  --secondary: #4C1D95;
  --accent: #6D28D9;
  --text: #1A0B3E;
  --muted: #8B85A0;
  --line: #D5D0E5;
  --alt-bg: #EDE8F5;
  --font-heading: 'Playfair Display', Georgia, serif;
  --font-body: 'Inter', 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 1.05rem;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); }

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* === 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; }
}

/* === Hero Section === */
.hero-section {
  position: relative;
  min-height: 520px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 5rem 1.5rem 4rem;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(46,16,101,0.92), rgba(76,29,149,0.85));
  z-index: 1;
}
.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
  color: #fff;
}
.hero-badge-row, .hero-badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}
.hero-affiliation {
  font-size: 0.95rem;
  color: rgba(255,255,255,0.6);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
}
.hero-abstract {
  font-size: 1rem;
  line-height: 1.65;
  color: rgba(255,255,255,0.85);
  margin-bottom: 2rem;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}
.chip {
  display: inline-block;
  background: rgba(109,40,217,0.5);
  color: #e8e0f5;
  padding: 0.3rem 0.9rem;
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border: 1px solid rgba(255,255,255,0.15);
}
.hero-content h1 {
  font-family: var(--font-heading);
  font-size: 2.8rem;
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 0.75rem;
}
.hero-byline {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.7);
  margin-bottom: 1rem;
}
.hero-subtitle {
  font-size: 1.1rem;
  line-height: 1.6;
  color: rgba(255,255,255,0.9);
  margin-bottom: 2rem;
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
}
.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}
.btn {
  display: inline-block;
  padding: 0.7rem 1.6rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: background 0.2s, transform 0.2s;
  background: var(--accent);
  color: #fff;
}
.btn:hover { background: #5b21b6; transform: translateY(-1px); }
.btn-outline {
  background: transparent;
  border: 2px solid rgba(255,255,255,0.4);
  color: #fff;
}
.btn-outline:hover { background: rgba(255,255,255,0.1); border-color: rgba(255,255,255,0.7); }
.btn-secondary {
  background: transparent;
  border: 2px solid rgba(255,255,255,0.4);
  color: #fff;
}
.btn-secondary:hover { background: rgba(255,255,255,0.1); border-color: rgba(255,255,255,0.7); }

/* === Content Sections === */
.content-section {
  padding: 4rem 0;
}
.content-section.alt-bg {
  background: var(--alt-bg);
}
.content-section h2 {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 1.5rem;
}
.content-section h3 {
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--secondary);
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}
.content-section p {
  margin-bottom: 1rem;
}

/* === Callout === */
.callout, .callout-box {
  background: var(--surface);
  border-left: 4px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
}
.callout-problem, .problem-callout { border-left-color: #9B2C2C; background: #FFF5F5; }

/* === Card Grid === */
.card-grid, .card-grid-2x2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-top: 1rem;
}
@media (max-width: 640px) {
  .card-grid, .card-grid-2x2 { grid-template-columns: 1fr; }
}
.contribution-card {
  background: var(--surface);
  border-radius: 12px;
  padding: 1.5rem;
  border-left: 4px solid var(--accent);
  box-shadow: 0 2px 12px rgba(46,16,101,0.08);
  transition: box-shadow 0.2s, transform 0.2s;
}
.contribution-card:hover {
  box-shadow: 0 4px 20px rgba(46,16,101,0.14);
  transform: translateY(-2px);
}
.card-icon {
  font-size: 1.8rem;
  margin-bottom: 0.5rem;
}
.contribution-card h3 {
  font-size: 1.15rem;
  margin-top: 0;
  margin-bottom: 0.5rem;
  color: var(--primary);
}

/* === Principle Grid === */
.principle-grid, .principles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 2rem;
}
@media (max-width: 768px) {
  .principle-grid, .principles-grid { grid-template-columns: 1fr; }
}
.principle-card {
  background: var(--surface);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: 0 2px 12px rgba(46,16,101,0.08);
}
.principle-card h3 {
  font-size: 1.1rem;
  margin-top: 0;
  color: var(--primary);
}

/* === Figure Cards === */
.figure-card {
  background: var(--surface);
  border-radius: 12px;
  padding: 1.5rem;
  margin: 2rem 0;
  box-shadow: 0 2px 12px rgba(46,16,101,0.08);
  border: 1px solid var(--line);
}
.figure-card img {
  border-radius: 8px;
  margin: 0 auto;
}
.figure-card figcaption {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: var(--muted);
  line-height: 1.5;
}
.figure-large img { width: 100%; }
.figure-medium { max-width: 600px; margin-left: auto; margin-right: auto; }

/* === Formula Box === */
.formula-box {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 1.5rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  font-family: var(--font-mono);
  text-align: center;
}

/* === Step List === */
.step-list, .extraction-steps {
  padding-left: 1.5rem;
  margin: 1rem 0;
}
.step-list li, .extraction-steps li {
  margin-bottom: 0.75rem;
}

/* === Step Cards === */
.step-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
}
@media (max-width: 768px) {
  .step-cards { grid-template-columns: 1fr; }
}
.step-card {
  background: var(--surface);
  border-radius: 12px;
  padding: 1.25rem;
  box-shadow: 0 2px 8px rgba(46,16,101,0.06);
  position: relative;
}
.step-num, .step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}
.step-card h4 {
  font-size: 1.05rem;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

/* === Two Column === */
.two-col, .two-col-cards, .impact-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-top: 1rem;
}
@media (max-width: 640px) {
  .two-col, .two-col-cards, .impact-grid { grid-template-columns: 1fr; }
}
.col-card, .info-card, .impact-card {
  background: var(--surface);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: 0 2px 12px rgba(46,16,101,0.08);
}
.col-card h3, .info-card h3, .impact-card h3 {
  margin-top: 0;
  font-size: 1.15rem;
}
.col-card.positive, .impact-card.positive {
  border-left: 4px solid #2E7D32;
  background: #F0F7F4;
}
.col-card.caution, .impact-card.caution {
  border-left: 4px solid #E65100;
  background: #FFF8F0;
}

/* === Result Cards === */
.result-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin: 1rem 0;
}
@media (max-width: 640px) {
  .result-cards { grid-template-columns: 1fr; }
}
.result-card {
  background: var(--surface);
  border-radius: 12px;
  padding: 1.5rem;
  border-left: 4px solid var(--accent);
  box-shadow: 0 2px 12px rgba(46,16,101,0.08);
}
.result-card h3 {
  margin-top: 0;
  font-size: 1.15rem;
}
.result-card.accent-border {
  border-left-color: var(--accent);
}

/* === Table === */
.table-wrapper, .table-container {
  overflow-x: auto;
  margin: 1.5rem 0;
}
table caption {
  text-align: left;
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 0.5rem;
  font-style: italic;
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}
thead th {
  background: var(--primary);
  color: #fff;
  padding: 0.75rem 1rem;
  text-align: left;
  font-weight: 600;
}
tbody td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--line);
}
.highlight-row td {
  background: rgba(109,40,217,0.08);
  font-weight: 600;
}

/* === Metric Highlight === */
.metric-highlight {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin: 1.5rem 0;
  padding: 1.25rem 1.5rem;
  background: linear-gradient(135deg, rgba(46,16,101,0.05), rgba(109,40,217,0.08));
  border-radius: 12px;
  border: 1px solid var(--line);
}
.metric-value {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--accent);
}
.metric-label {
  font-size: 1rem;
  color: var(--muted);
}

/* === Limitation List === */
.limitation-list, .limitations-list {
  list-style: none;
  padding: 0;
}
.limitation-list li, .limitations-list li {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--line);
  padding-left: 1rem;
  position: relative;
}
.limitation-list li::before, .limitations-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--muted);
}

/* === Highlight Box === */
.highlight-box {
  background: linear-gradient(135deg, rgba(46,16,101,0.06), rgba(109,40,217,0.1));
  border: 1px solid var(--accent);
  border-radius: 12px;
  padding: 1.5rem;
  margin-top: 1.5rem;
}

/* === Details/Summary === */
details {
  margin: 1rem 0;
}
summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--primary);
  padding: 0.75rem 0;
  list-style: revert;
}
summary:hover { color: var(--accent); }

/* === References === */
.references-list {
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.6;
  padding-left: 2rem;
}
.references-list li {
  margin-bottom: 0.5rem;
}

/* === Flecto Explanation UI Classes === */
.flecto-note,
.flecto-callout,
.flecto-card,
.flecto-panel {
  margin: 1.25rem 0;
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
}
.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-note {
  background: rgba(109,40,217,0.04);
  border-left: 3px solid #60a5fa;
  font-size: 0.95rem;
  padding: 0.9rem 1.2rem;
}
.flecto-callout {
  background: rgba(96,165,250,0.08);
  border: 1px solid rgba(96,165,250,0.25);
  padding: 1.25rem 1.5rem;
}
.flecto-card {
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: 0 2px 8px rgba(46,16,101,0.06);
}
.flecto-card h4, .flecto-panel h4 {
  font-size: 1.05rem;
  color: var(--primary);
  margin-bottom: 0.5rem;
}
.flecto-panel {
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: 0 2px 12px rgba(46,16,101,0.08);
  padding: 1.5rem 2rem;
}

/* === Responsive === */
@media (max-width: 480px) {
  .hero-content h1 { font-size: 1.8rem; }
  .hero-section { padding: 3rem 1rem 2.5rem; min-height: auto; }
  .content-section { padding: 2.5rem 0; }
  .content-section h2 { font-size: 1.6rem; }
  .metric-value { font-size: 2rem; }
}