:root {
  --bg-primary: #060913;
  --bg-secondary: #0c1222;
  --bg-card: rgba(16, 24, 45, 0.78);
  --bg-card-hover: rgba(24, 36, 66, 0.92);
  --border-subtle: rgba(99, 179, 237, 0.16);
  --border-glow: rgba(56, 189, 248, 0.45);
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-cyan: #22d3ee;
  --accent-emerald: #34d399;
  --accent-violet: #a78bfa;
  --accent-amber: #fbbf24;
  --accent-rose: #fb7185;
  --font-sans: 'Inter', 'Hiragino Kaku Gothic ProN', 'Noto Sans JP', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

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

html {
  scroll-behavior: smooth;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.7;
}

body {
  background:
    radial-gradient(circle at 15% 10%, rgba(34, 211, 238, 0.08), transparent 40%),
    radial-gradient(circle at 85% 25%, rgba(167, 139, 250, 0.08), transparent 45%),
    radial-gradient(circle at 50% 80%, rgba(52, 211, 153, 0.06), transparent 50%),
    var(--bg-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  background: rgba(6, 9, 19, 0.82);
  border-bottom: 1px solid var(--border-subtle);
}

.nav-container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0.9rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}

.brand-orb {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: conic-gradient(from 120deg, var(--accent-cyan), var(--accent-emerald), var(--accent-violet), var(--accent-cyan));
  box-shadow: 0 0 16px rgba(34, 211, 238, 0.5);
  position: relative;
}

.brand-orb::after {
  content: '';
  position: absolute;
  inset: 5px;
  border-radius: 50%;
  background: var(--bg-primary);
}

.nav-links {
  display: flex;
  gap: 1.25rem;
  list-style: none;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-links a:hover {
  color: var(--accent-cyan);
}

/* Layout Container */
.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Hero Section */
.hero {
  padding: 4.5rem 0 3rem;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2.5rem;
  align-items: center;
}

@media (max-width: 960px) {
  .hero {
    grid-template-columns: 1fr;
    padding: 3rem 0 2rem;
  }
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  background: rgba(34, 211, 238, 0.1);
  color: var(--accent-cyan);
  border: 1px solid rgba(34, 211, 238, 0.3);
  margin-bottom: 1.25rem;
}

.hero h1 {
  font-size: clamp(2rem, 3.6vw, 3.1rem);
  line-height: 1.22;
  font-weight: 800;
  margin-bottom: 1.25rem;
  background: linear-gradient(135deg, #ffffff 0%, #bae6fd 55%, #a78bfa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-lead {
  font-size: 1.06rem;
  color: var(--text-secondary);
  margin-bottom: 1.75rem;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.35rem;
  border-radius: 0.6rem;
  font-weight: 600;
  font-size: 0.92rem;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s ease;
  border: 1px solid transparent;
}

.btn-primary {
  background: linear-gradient(135deg, #0ea5e9, #10b981);
  color: #041019;
  box-shadow: 0 4px 20px rgba(14, 165, 233, 0.3);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 25px rgba(14, 165, 233, 0.45);
}

.btn-outline {
  background: rgba(15, 23, 42, 0.7);
  color: var(--text-primary);
  border-color: var(--border-subtle);
}

.btn-outline:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

/* Hero Metrics Card */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 0.9rem;
  padding: 1.25rem;
  transition: border-color 0.25s ease, transform 0.25s ease;
}

.stat-card:hover {
  border-color: var(--border-glow);
  transform: translateY(-2px);
}

.stat-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent-cyan);
  margin-bottom: 0.3rem;
  display: block;
}

.stat-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
  color: var(--text-primary);
}

.stat-desc {
  font-size: 0.84rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Section Headers */
.section {
  padding: 4rem 0;
  border-top: 1px solid rgba(99, 179, 237, 0.1);
}

.section-header {
  margin-bottom: 2.25rem;
}

.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-emerald);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: 0.4rem;
}

.section-title {
  font-size: clamp(1.55rem, 2.5vw, 2.15rem);
  font-weight: 800;
  margin-bottom: 0.6rem;
}

.section-subtitle {
  color: var(--text-secondary);
  max-width: 780px;
  font-size: 0.98rem;
}

/* Interactive Simulation Lab */
.sim-lab {
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 1.1rem;
  padding: 1.5rem;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.45);
}

@media (max-width: 960px) {
  .sim-lab {
    grid-template-columns: 1fr;
  }
}

.sim-viewport {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.sim-tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.sim-tab {
  padding: 0.55rem 1rem;
  border-radius: 0.5rem;
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.86rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.sim-tab.active {
  background: rgba(34, 211, 238, 0.15);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

.canvas-wrapper {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  background: #03060c;
  border-radius: 0.75rem;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

#alife-canvas {
  width: 100%;
  height: 100%;
  display: block;
  cursor: crosshair;
}

.canvas-overlay {
  position: absolute;
  bottom: 0.75rem;
  left: 0.85rem;
  right: 0.85rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  pointer-events: none;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: rgba(241, 245, 249, 0.75);
  background: rgba(6, 9, 19, 0.65);
  backdrop-filter: blur(6px);
  padding: 0.35rem 0.75rem;
  border-radius: 0.45rem;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.sim-controls {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1.25rem;
  background: rgba(8, 13, 26, 0.75);
  padding: 1.25rem;
  border-radius: 0.8rem;
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.sim-info h3 {
  font-size: 1.1rem;
  margin-bottom: 0.4rem;
  color: var(--accent-cyan);
}

.sim-info p {
  font-size: 0.86rem;
  color: var(--text-secondary);
  margin-bottom: 0.9rem;
}

.formula-box {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  background: rgba(2, 6, 23, 0.9);
  border-left: 3px solid var(--accent-violet);
  padding: 0.65rem 0.8rem;
  border-radius: 0.35rem;
  color: #e2e8f0;
  overflow-x: auto;
  margin-bottom: 1rem;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.slider-item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.slider-header {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.slider-header span:last-child {
  font-family: var(--font-mono);
  color: var(--accent-emerald);
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent-cyan);
  cursor: pointer;
}

.sim-btn-row {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.sim-btn {
  flex: 1;
  padding: 0.55rem 0.75rem;
  border-radius: 0.45rem;
  border: 1px solid var(--border-subtle);
  background: rgba(30, 41, 59, 0.7);
  color: var(--text-primary);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.sim-btn:hover {
  border-color: var(--accent-cyan);
  background: rgba(34, 211, 238, 0.15);
}

/* 3 Pillars Grid (Soft / Hard / Wet + Hybrid) */
.pillars-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
}

.pillar-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 0.95rem;
  padding: 1.6rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  transition: transform 0.25s ease, border-color 0.25s ease;
}

.pillar-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-glow);
}

.pillar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.pillar-domain {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  padding: 0.25rem 0.65rem;
  border-radius: 99px;
  font-weight: 600;
}

.domain-soft {
  background: rgba(34, 211, 238, 0.12);
  color: var(--accent-cyan);
}

.domain-wet {
  background: rgba(52, 211, 153, 0.12);
  color: var(--accent-emerald);
}

.domain-hybrid {
  background: rgba(167, 139, 250, 0.12);
  color: var(--accent-violet);
}

.domain-ai {
  background: rgba(251, 191, 36, 0.12);
  color: var(--accent-amber);
}

.pillar-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
}

.pillar-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.key-points {
  list-style: none;
  margin-top: auto;
  padding-top: 0.75rem;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.key-points li {
  font-size: 0.83rem;
  color: var(--text-primary);
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}

.key-points li::before {
  content: '▹';
  color: var(--accent-cyan);
  font-weight: bold;
}

/* Deep Dive Essay Cards / Accordion */
.deep-dive-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

@media (max-width: 860px) {
  .deep-dive-grid {
    grid-template-columns: 1fr;
  }
}

.essay-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 0.95rem;
  padding: 1.75rem;
}

.essay-card h3 {
  font-size: 1.18rem;
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: #e2e8f0;
}

.essay-num {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--accent-cyan);
  background: rgba(34, 211, 238, 0.12);
  padding: 0.2rem 0.55rem;
  border-radius: 0.4rem;
}

.essay-card p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  margin-bottom: 0.9rem;
}

.essay-quote {
  font-size: 0.85rem;
  padding: 0.75rem 1rem;
  background: rgba(15, 23, 42, 0.75);
  border-left: 3px solid var(--accent-emerald);
  border-radius: 0.4rem;
  color: var(--text-primary);
}

/* Landmark Papers & Timeline Explorer */
.filter-bar {
  display: flex;
  gap: 0.6rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 0.45rem 0.95rem;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
  border: 1px solid var(--border-subtle);
  background: rgba(15, 23, 42, 0.7);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.filter-btn.active,
.filter-btn:hover {
  background: rgba(52, 211, 153, 0.15);
  border-color: var(--accent-emerald);
  color: var(--accent-emerald);
}

.papers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.15rem;
}

.paper-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 0.85rem;
  padding: 1.35rem;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  transition: border-color 0.2s ease;
}

.paper-card:hover {
  border-color: var(--accent-emerald);
}

.paper-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--accent-amber);
}

.paper-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.paper-authors {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.paper-summary {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
  flex-grow: 1;
}

.paper-card-title-link {
  color: var(--text-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.paper-card-title-link:hover {
  color: var(--accent-cyan);
}

.paper-card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-top: 0.85rem;
  padding-top: 0.85rem;
  border-top: 1px solid rgba(255, 255, 255, 0.07);
  align-items: center;
  justify-content: space-between;
}

.paper-detail-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent-cyan);
  background: rgba(34, 211, 238, 0.12);
  border: 1px solid rgba(34, 211, 238, 0.3);
  padding: 0.42rem 0.85rem;
  border-radius: 0.45rem;
  text-decoration: none;
  transition: all 0.2s ease;
}

.paper-detail-btn:hover {
  background: rgba(34, 211, 238, 0.22);
  border-color: var(--accent-cyan);
  transform: translateY(-1px);
}

.paper-ext-links {
  display: flex;
  gap: 0.45rem;
  flex-wrap: wrap;
}

.paper-ext-link {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--text-secondary);
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid var(--border-subtle);
  padding: 0.35rem 0.65rem;
  border-radius: 0.4rem;
  text-decoration: none;
  transition: all 0.2s ease;
}

.paper-ext-link:hover {
  color: var(--accent-emerald);
  border-color: var(--accent-emerald);
}

/* ==========================================
   DEDICATED PAPER ARTICLE PAGE STYLES
   ========================================== */
.breadcrumb-bar {
  padding: 1.5rem 0 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.breadcrumb-bar a {
  color: var(--accent-cyan);
  text-decoration: none;
}

.breadcrumb-bar a:hover {
  text-decoration: underline;
}

.article-hero {
  padding: 2rem 0 2.5rem;
  border-bottom: 1px solid var(--border-subtle);
}

.article-meta-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.article-year-badge {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--accent-amber);
  background: rgba(251, 191, 36, 0.12);
  border: 1px solid rgba(251, 191, 36, 0.3);
  padding: 0.28rem 0.75rem;
  border-radius: 999px;
}

.article-cat-badge {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent-emerald);
  background: rgba(52, 211, 153, 0.12);
  border: 1px solid rgba(52, 211, 153, 0.3);
  padding: 0.28rem 0.75rem;
  border-radius: 999px;
}

.article-title {
  font-size: clamp(1.75rem, 3.2vw, 2.6rem);
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 0.65rem;
  color: #ffffff;
}

.article-subtitle-ja {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-bottom: 1.15rem;
}

.article-authors-box {
  background: rgba(15, 23, 42, 0.75);
  border: 1px solid var(--border-subtle);
  border-radius: 0.75rem;
  padding: 1rem 1.25rem;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  display: grid;
  gap: 0.35rem;
}

.article-authors-box strong {
  color: var(--text-primary);
}

.original-links-panel {
  background: rgba(16, 24, 45, 0.9);
  border: 1px solid rgba(34, 211, 238, 0.35);
  border-radius: 0.85rem;
  padding: 1.25rem 1.5rem;
  margin-top: 1.25rem;
}

.original-links-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-cyan);
  margin-bottom: 0.75rem;
  display: block;
}

.original-links-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.orig-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.6rem 1.1rem;
  border-radius: 0.55rem;
  font-size: 0.86rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
}

.orig-btn-primary {
  background: linear-gradient(135deg, #0ea5e9, #10b981);
  color: #041019;
}

.orig-btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(14, 165, 233, 0.4);
}

.orig-btn-secondary {
  background: rgba(15, 23, 42, 0.85);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
}

.orig-btn-secondary:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

.article-layout {
  display: grid;
  grid-template-columns: 1fr 310px;
  gap: 2.25rem;
  padding: 2.5rem 0 3rem;
  align-items: start;
}

@media (max-width: 960px) {
  .article-layout {
    grid-template-columns: 1fr;
  }
}

.article-body {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.article-section {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 0.95rem;
  padding: 1.85rem;
}

.article-section h2 {
  font-size: 1.32rem;
  font-weight: 700;
  color: #f8fafc;
  margin-bottom: 1rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.sec-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-cyan);
  background: rgba(34, 211, 238, 0.12);
  padding: 0.2rem 0.55rem;
  border-radius: 0.35rem;
}

.article-section h3 {
  font-size: 1.06rem;
  font-weight: 700;
  color: var(--accent-emerald);
  margin: 1.25rem 0 0.5rem;
}

.article-section p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 0.95rem;
  line-height: 1.8;
}

.article-section p:last-child {
  margin-bottom: 0;
}

.article-section ul,
.article-section ol {
  padding-left: 1.35rem;
  margin-bottom: 1rem;
  color: var(--text-secondary);
  font-size: 0.93rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.article-section li strong {
  color: var(--text-primary);
}

.math-block {
  font-family: var(--font-mono);
  font-size: 0.86rem;
  background: rgba(2, 6, 23, 0.92);
  border: 1px solid rgba(167, 139, 250, 0.3);
  border-left: 4px solid var(--accent-violet);
  padding: 1rem 1.2rem;
  border-radius: 0.5rem;
  color: #e2e8f0;
  overflow-x: auto;
  margin: 1rem 0;
  line-height: 1.65;
}

.highlight-callout {
  background: rgba(16, 185, 129, 0.08);
  border-left: 4px solid var(--accent-emerald);
  padding: 1rem 1.25rem;
  border-radius: 0.45rem;
  margin: 1rem 0;
  font-size: 0.92rem;
  color: var(--text-primary);
}

.article-sidebar {
  position: sticky;
  top: 5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.sidebar-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 0.85rem;
  padding: 1.35rem;
}

.sidebar-card h3 {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-cyan);
  margin-bottom: 0.85rem;
}

.sidebar-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  font-size: 0.85rem;
}

.sidebar-list a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.15s ease;
  display: block;
  line-height: 1.4;
}

.sidebar-list a:hover,
.sidebar-list a.current {
  color: var(--accent-cyan);
  font-weight: 600;
}

.article-nav-footer {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
  padding: 2rem 0;
  border-top: 1px solid var(--border-subtle);
}

@media (max-width: 640px) {
  .article-nav-footer {
    grid-template-columns: 1fr;
  }
}

.nav-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 0.8rem;
  padding: 1.15rem 1.35rem;
  text-decoration: none;
  transition: all 0.2s ease;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.nav-card:hover {
  border-color: var(--accent-cyan);
  transform: translateY(-2px);
}

.nav-card-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.nav-card-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
}

/* Future Challenges Table */
.matrix-table-wrapper {
  overflow-x: auto;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 0.95rem;
}

.matrix-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.9rem;
}

.matrix-table th,
.matrix-table td {
  padding: 1.05rem 1.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.matrix-table th {
  background: rgba(15, 23, 42, 0.85);
  color: var(--accent-cyan);
  font-weight: 700;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.matrix-table tr:last-child td {
  border-bottom: none;
}

/* Footer */
.site-footer {
  margin-top: 4rem;
  padding: 2.5rem 0;
  border-top: 1px solid var(--border-subtle);
  background: rgba(4, 7, 15, 0.9);
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}