:root {
  --bg-main: #0a0d12;
  --bg-card: #121721;
  --bg-card-hover: #171e2b;
  --bg-card-subtle: #0d121a;
  --border-color: #1f2937;
  --border-focus: #3b82f6;
  --text-primary: #f3f4f6;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --accent-glow: rgba(59, 130, 246, 0.15);
  --green: #10b981;
  --green-glow: rgba(16, 185, 129, 0.15);
  --red: #ef4444;
  --red-glow: rgba(239, 68, 68, 0.15);
  --amber: #f59e0b;
  --purple: #8b5cf6;
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --transition: all 0.2s ease-in-out;
}

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

body {
  background-color: var(--bg-main);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  text-decoration: underline;
}

.app-container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 32px 24px 64px 24px;
}

/* Header */
.site-header {
  margin-bottom: 36px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 24px;
}

.header-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 28px;
}

.brand-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--accent);
  background: var(--accent-glow);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  border: 1px solid rgba(59, 130, 246, 0.3);
}

.brand-title {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #fff;
}

.brand-title span {
  color: var(--accent);
}

.brand-sub {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-top: 4px;
}

.header-meta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.author-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: 9999px;
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 500;
}

.author-pill:hover {
  border-color: var(--accent);
  text-decoration: none;
}

.author-pill .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 8px var(--green);
}

.version-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  background: var(--bg-card-subtle);
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

/* KPI Strip */
.kpi-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 28px;
}

.kpi-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.kpi-card:hover {
  border-color: #374151;
  background: var(--bg-card-hover);
}

.kpi-card.accent {
  border-color: rgba(59, 130, 246, 0.4);
  background: linear-gradient(145deg, var(--bg-card) 0%, rgba(59, 130, 246, 0.08) 100%);
}

.kpi-label {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-weight: 600;
  margin-bottom: 6px;
}

.kpi-value {
  font-family: var(--font-mono);
  font-size: 1.8rem;
  font-weight: 700;
  color: #fff;
}

.kpi-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Navigation Tabs */
.nav-tabs {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 4px;
}

.nav-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.92rem;
  font-weight: 600;
  padding: 10px 18px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.nav-btn:hover {
  color: #fff;
  background: var(--bg-card);
}

.nav-btn.active {
  color: #fff;
  background: var(--bg-card);
  border-color: var(--border-color);
  box-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

/* Tab Panes */
.tab-pane {
  display: none;
  animation: fadeIn 0.25s ease-in-out;
}

.tab-pane.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

.section-intro {
  margin-bottom: 28px;
}

.section-intro h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.section-intro p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Tab 1: Pillars Grid */
.pillars-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 20px;
}

.pillar-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.pillar-card:hover {
  border-color: #3b82f666;
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.pillar-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.pillar-card .pillar-sub {
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 12px;
}

.pillar-card .pillar-summary {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
  line-height: 1.5;
}

.pillar-card ul {
  list-style-type: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.pillar-card li {
  font-size: 0.82rem;
  color: #d1d5db;
  position: relative;
  padding-left: 18px;
}

.pillar-card li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-family: var(--font-mono);
}

/* Tab 2: Simulator Layout */
.simulator-layout {
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 24px;
}

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

.sim-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.sim-panel h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 12px;
}

.form-group {
  margin-bottom: 18px;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.form-select, .form-input, .form-textarea {
  width: 100%;
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  color: #fff;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  transition: var(--transition);
}

.form-select:focus, .form-input:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent-glow);
}

.form-range {
  width: 100%;
  accent-color: var(--accent);
  cursor: pointer;
}

.range-val {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: right;
  margin-top: 4px;
}

.input-prefix {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  color: var(--text-muted);
}

.form-hint {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 4px;
}

.btn-primary {
  width: 100%;
  background: var(--accent);
  color: #fff;
  border: none;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.btn-primary:hover {
  background: var(--accent-hover);
}

/* Comparison Cards */
.comparison-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 24px;
}

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

.comp-box {
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px;
  display: flex;
  flex-direction: column;
}

.comp-box.gateway {
  border-top: 3px solid var(--red);
}

.comp-box.tokenops {
  border-top: 3px solid var(--green);
}

.comp-header {
  margin-bottom: 14px;
}

.comp-header h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-top: 4px;
}

.badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

.badge.red {
  color: var(--red);
  background: var(--red-glow);
}

.badge.green {
  color: var(--green);
  background: var(--green-glow);
}

.metric-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 0;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  font-size: 0.85rem;
}

.metric-lbl {
  color: var(--text-secondary);
}

.metric-val {
  font-family: var(--font-mono);
  font-weight: 600;
}

.metric-val.red {
  color: var(--red);
}

.metric-val.green {
  color: var(--green);
}

.comp-narrative {
  margin-top: 14px;
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.45;
}

/* Timeline Box */
.timeline-box h4 {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.timeline-bars {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.hop-row {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.8rem;
}

.hop-label {
  font-family: var(--font-mono);
  width: 140px;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.hop-bar-track {
  flex: 1;
  height: 14px;
  background: rgba(255,255,255,0.06);
  border-radius: 4px;
  overflow: hidden;
  position: relative;
}

.hop-bar-fill {
  height: 100%;
  background: var(--accent);
  transition: width 0.3s ease;
}

.hop-bar-fill.halted {
  background: repeating-linear-gradient(
    45deg,
    var(--red),
    var(--red) 8px,
    #7f1d1d 8px,
    #7f1d1d 16px
  );
}

.hop-cost {
  font-family: var(--font-mono);
  width: 70px;
  text-align: right;
  color: #fff;
}

/* Tab 3: Study Syllabus */
.syllabus-list {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.phase-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 22px;
}

.phase-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.phase-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-glow);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
}

.phase-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 14px;
}

.topic-item {
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.topic-checkbox {
  margin-top: 4px;
  accent-color: var(--green);
  cursor: pointer;
  width: 16px;
  height: 16px;
}

.topic-content h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 2px;
}

.topic-content p {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* Tab 4: Papers & Citations */
.papers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 20px;
}

.paper-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.paper-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--amber);
  background: rgba(245, 158, 11, 0.12);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
}

.paper-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 6px;
  line-height: 1.4;
}

.paper-author {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.paper-highlights {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 20px;
}

.paper-highlights li {
  font-size: 0.82rem;
  color: #d1d5db;
  position: relative;
  padding-left: 18px;
  line-height: 1.45;
}

.paper-highlights li::before {
  content: "•";
  position: absolute;
  left: 4px;
  color: var(--accent);
}

.paper-links {
  display: flex;
  gap: 12px;
  padding-top: 14px;
  border-top: 1px solid var(--border-color);
}

.link-btn {
  font-size: 0.82rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* Tab 5: Notes Layout */
.notes-layout {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 24px;
}

@media (max-width: 840px) {
  .notes-layout {
    grid-template-columns: 1fr;
  }
}

.note-form-card, .notes-list-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.notes-feed {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 16px;
}

.note-entry {
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px;
}

.note-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.note-header h4 {
  font-size: 0.95rem;
  font-weight: 700;
}

.note-cat {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  background: var(--accent-glow);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

.note-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.note-body {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Footer */
.site-footer {
  margin-top: 60px;
  border-top: 1px solid var(--border-color);
  padding-top: 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-sub {
  font-size: 0.78rem;
  margin-top: 6px;
  color: #4b5563;
}