/* FORGE Paper — Kinetic Forge Design System */
/* Precision Industrialism: Dark Steel + Industrial Orange + Electric Blue */

@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@300;400;500;600;700&family=Inter:wght@300;400;500;600;700&family=Space+Mono:wght@400;700&display=swap');

:root {
  --background: #0e1321;
  --surface: #0e1321;
  --surface-container: #1a1f2e;
  --surface-container-low: #161b2a;
  --surface-container-high: #252a39;
  --surface-container-highest: #2f3444;
  --surface-container-lowest: #090e1c;

  --primary: #FF6B35;
  --primary-ambient: #ffb59d;
  --secondary: #00b2d6;
  --secondary-light: #4cd6fb;
  --tertiary: #b9c8de;

  --text-primary: #dee2f7;
  --text-secondary: #e1bfb5;
  --outline: #a98a80;
  --outline-variant: #594139;

  --font-heading: 'Space Grotesk', sans-serif;
  --font-body: 'Inter', sans-serif;
  --font-mono: 'Space Mono', monospace;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--background);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
}

/* ─── Typography ─── */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
}
h1 { font-size: 2.8rem; letter-spacing: -0.01em; }
h2 { font-size: 1.75rem; letter-spacing: 0.01em; margin-bottom: 1.5rem; }
h3 { font-size: 1.25rem; font-weight: 600; margin-bottom: 1rem; }
h4 { font-size: 1rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-secondary); }
p { margin-bottom: 1rem; color: var(--text-primary); }
a { color: var(--secondary); text-decoration: none; }
a:hover { color: var(--secondary-light); }

.mono { font-family: var(--font-mono); }
.label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
}
.section-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--primary);
  margin-bottom: 0.75rem;
  display: block;
}

/* ─── Layout ─── */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}
.section {
  padding: 80px 0;
}
.section-alt {
  background: var(--surface-container-low);
}

/* ─── Flecto Back Header ─── */
.flecto-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;
}
.flecto-header a {
  color: #8b8bcd;
  text-decoration: none;
}

/* ─── Buttons ─── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.25rem;
  font-family: var(--font-heading);
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: 0;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
  text-decoration: none;
}
.btn-primary {
  background: var(--primary);
  color: #390c00;
  border: none;
}
.btn-primary:hover { background: #e55a28; color: #390c00; }
.btn-secondary {
  background: transparent;
  color: var(--primary);
  border: 1px solid rgba(255, 107, 53, 0.3);
}
.btn-secondary:hover { background: rgba(255, 107, 53, 0.1); }
.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid rgba(161, 138, 128, 0.3);
}
.btn-ghost:hover { background: rgba(255,255,255,0.05); color: var(--text-primary); }

/* ─── Hero Section ─── */
#hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
  overflow: hidden;
}
.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(14, 19, 33, 0.78) 0%,
    rgba(14, 19, 33, 0.65) 60%,
    rgba(14, 19, 33, 0.82) 100%
  );
  z-index: 1;
}
.hero-glow {
  position: absolute;
  bottom: -100px;
  left: -100px;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(255, 107, 53, 0.08) 0%, transparent 70%);
  z-index: 1;
}
#hero .container {
  position: relative;
  z-index: 2;
  max-width: 900px;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.75rem;
  background: var(--surface-container-highest);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  border-left: 3px solid var(--primary);
}
#hero h1 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 1rem;
  line-height: 1.15;
}
.hero-authors {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-family: var(--font-body);
}
.hero-authors .equal-contrib {
  color: var(--primary);
  font-size: 0.8rem;
}
.hero-metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2rem;
}
.metric-badge {
  background: var(--surface-container-high);
  padding: 1rem 1.5rem;
  border-left: 3px solid var(--primary);
  min-width: 140px;
}
.metric-badge .metric-value {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
  display: block;
  line-height: 1;
  margin-bottom: 0.25rem;
}
.metric-badge .metric-label {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
}
.hero-abstract {
  font-size: 1rem;
  color: var(--text-primary);
  max-width: 700px;
  margin-bottom: 2.5rem;
  line-height: 1.75;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ─── Stats Card ─── */
.stats-card {
  background: var(--surface-container-high);
  padding: 1.5rem;
  position: relative;
}
.stats-card-header {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--outline-variant);
}
.stats-card ul {
  list-style: none;
  padding: 0;
}
.stats-card ul li {
  padding: 0.4rem 0;
  font-size: 0.9rem;
  color: var(--text-primary);
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
}
.stats-card ul li::before {
  content: "✓";
  color: var(--primary);
  font-weight: 700;
  flex-shrink: 0;
}

/* ─── Two-column layout ─── */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}
@media (max-width: 768px) { .two-col { grid-template-columns: 1fr; } }

/* ─── Contribution Cards Grid ─── */
.contrib-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}
@media (max-width: 768px) { .contrib-grid { grid-template-columns: 1fr; } }
.contrib-card {
  background: var(--surface-container-high);
  padding: 1.5rem;
  border-top: 3px solid var(--primary);
}
.contrib-card .contrib-number {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
}
.contrib-card h3 { margin-bottom: 0.5rem; font-size: 1rem; }
.contrib-card p { font-size: 0.875rem; color: var(--text-secondary); margin: 0; }

/* ─── Data Table ─── */
.data-table-wrap { overflow-x: auto; margin: 1.5rem 0; }
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}
.data-table th {
  background: var(--surface-container-high);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 2px solid var(--primary);
}
.data-table td {
  padding: 0.65rem 1rem;
  border-bottom: 1px solid rgba(89, 65, 57, 0.3);
  color: var(--text-primary);
}
.data-table tr:hover td { background: rgba(255,255,255,0.02); }
.data-table tr.forge-row td {
  background: rgba(255, 107, 53, 0.07);
  font-weight: 600;
  color: var(--primary);
}
.data-table .check { color: var(--primary); }
.data-table .cross { color: #ff6b6b; opacity: 0.7; }

/* ─── Task Cards ─── */
.task-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 2rem;
}
@media (max-width: 900px) { .task-grid { grid-template-columns: 1fr; } }
.task-card {
  background: var(--surface-container-high);
  padding: 1.5rem;
  border-top: 3px solid var(--secondary);
}
.task-tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--secondary);
  margin-bottom: 0.75rem;
  display: block;
}
.task-card h3 { font-size: 1rem; margin-bottom: 0.5rem; }
.task-card p { font-size: 0.875rem; color: var(--text-secondary); margin: 0; }

/* ─── Insight Cards ─── */
.insight-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}
@media (max-width: 768px) { .insight-grid { grid-template-columns: 1fr; } }
.insight-card {
  background: var(--surface-container-high);
  padding: 1.5rem;
  display: flex;
  gap: 1rem;
}
.insight-badge {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
  flex-shrink: 0;
  line-height: 1;
  padding-top: 0.1rem;
}
.insight-card h3 { font-size: 0.95rem; margin-bottom: 0.4rem; }
.insight-card p { font-size: 0.875rem; color: var(--text-secondary); margin: 0; }

/* ─── Bottleneck Cards ─── */
.bottleneck-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 2rem;
}
@media (max-width: 900px) { .bottleneck-grid { grid-template-columns: 1fr; } }
.bottleneck-card {
  background: var(--surface-container-high);
  padding: 1.5rem;
  border-top: 3px solid var(--secondary);
}
.bottleneck-card .bottle-tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--secondary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.75rem;
  display: block;
}
.bottleneck-card h3 { font-size: 0.95rem; margin-bottom: 0.5rem; }
.bottleneck-card p { font-size: 0.875rem; color: var(--text-secondary); margin: 0; }

/* ─── SFT Metric Hero ─── */
.sft-metric-hero {
  background: var(--surface-container-high);
  padding: 2.5rem;
  text-align: center;
  border: 1px solid rgba(255, 107, 53, 0.2);
  margin-bottom: 2rem;
  position: relative;
  overflow: hidden;
}
.sft-metric-hero::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
}
.sft-big-number {
  font-family: var(--font-mono);
  font-size: 4rem;
  font-weight: 700;
  color: var(--primary);
  display: block;
  line-height: 1;
  margin-bottom: 0.5rem;
  text-shadow: 0 0 40px rgba(255, 107, 53, 0.3);
}
.sft-sub-metric {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  color: var(--secondary);
  margin-bottom: 0.75rem;
}
.sft-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
}

/* ─── Figure/Callout ─── */
.source-figure {
  margin: 2rem 0;
}
.source-figure img {
  width: 100%;
  border: 1px solid var(--outline-variant);
  display: block;
}
.source-figure figcaption {
  font-size: 0.825rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
  font-family: var(--font-body);
  padding: 0.5rem;
  background: var(--surface-container-low);
  border-left: 3px solid var(--outline-variant);
}

/* ─── Callout / Highlight ─── */
.callout {
  background: rgba(0, 178, 214, 0.08);
  border-left: 3px solid var(--secondary);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  font-size: 0.9rem;
}
.callout strong { color: var(--secondary); }
.callout-orange {
  background: rgba(255, 107, 53, 0.08);
  border-left: 3px solid var(--primary);
}
.callout-orange strong { color: var(--primary); }

/* ─── Keyword chips ─── */
.chip-container { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 1rem 0; }
.chip {
  background: var(--surface-container-highest);
  color: var(--text-secondary);
  padding: 0.3rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ─── References accordion ─── */
details summary {
  cursor: pointer;
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 600;
  padding: 1rem 1.5rem;
  background: var(--surface-container-high);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
details summary::-webkit-details-marker { display: none; }
details summary::before {
  content: "▶";
  color: var(--primary);
  font-size: 0.8rem;
  transition: transform 0.2s;
}
details[open] summary::before { transform: rotate(90deg); }
.references-list {
  padding: 1.5rem;
  background: var(--surface-container-low);
}
.references-list li {
  padding: 0.4rem 0;
  border-bottom: 1px solid rgba(89,65,57,0.2);
  font-size: 0.875rem;
  color: var(--text-secondary);
  list-style-position: inside;
}

/* ─── Flecto Note/Callout/Card/Panel (AI explanation) ─── */
.flecto-note,
.flecto-callout,
.flecto-card,
.flecto-panel {
  margin: 1.5rem 0;
  padding: 1rem 1.25rem;
}
.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(76, 214, 251, 0.06);
  border-left: 3px solid var(--secondary-light);
  font-size: 0.875rem;
}
.flecto-callout {
  background: rgba(255, 107, 53, 0.08);
  border-left: 4px solid var(--primary);
  font-size: 0.9rem;
}
.flecto-card {
  background: var(--surface-container-high);
  border: 1px solid var(--outline-variant);
  font-size: 0.9rem;
}
.flecto-panel {
  background: var(--surface-container-highest);
  border-top: 3px solid var(--secondary);
  font-size: 0.9rem;
}

/* ─── Reveal Animation ─── */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}
.reveal.visible, .reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

/* ─── Responsive ─── */
@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.4rem; }
  #hero { min-height: auto; padding: 100px 0 60px; }
  .hero-metrics { gap: 0.75rem; }
  .metric-badge { min-width: 120px; padding: 0.75rem 1rem; }
  .metric-badge .metric-value { font-size: 1.5rem; }
  .sft-big-number { font-size: 3rem; }
  .task-grid, .bottleneck-grid { grid-template-columns: 1fr; }
}