/* ============================================
   MICRO ATTENTION — Design Tokens & Styles
   Technical/developer aesthetic:
   Deep navy surfaces, amber/gold accents,
   monospace + geometric sans pairing
   ============================================ */

:root, [data-theme="light"] {
  /* Type scale */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-hero: clamp(2.5rem,   1rem    + 4vw,    5rem);

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Light mode surfaces — cool slate/paper */
  --color-bg:              #f4f5f7;
  --color-surface:         #f9fafb;
  --color-surface-2:       #ffffff;
  --color-surface-offset:  #eaecf0;
  --color-surface-offset-2:#e2e5ea;
  --color-surface-dynamic: #d8dce3;
  --color-divider:         #d0d4dc;
  --color-border:          #c4c9d4;

  /* Text */
  --color-text:            #1a1d24;
  --color-text-muted:      #6b7280;
  --color-text-faint:      #9ca3af;
  --color-text-inverse:    #f4f5f7;

  /* Primary accent — amber/gold (Attention = focus = spotlight) */
  --color-primary:         #b45309;
  --color-primary-hover:   #92400e;
  --color-primary-active:  #78350f;
  --color-primary-highlight: #fde68a;

  /* Secondary — indigo/violet for Q/K/V matrix colors */
  --color-indigo:          #4338ca;
  --color-violet:          #7c3aed;
  --color-rose:            #be123c;
  --color-emerald:         #065f46;
  --color-sky:             #0369a1;

  /* Success / Warning / Error */
  --color-success:         #15803d;
  --color-warning:         #b45309;
  --color-error:           #be123c;

  /* Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Shadows */
  --shadow-sm: 0 1px 3px oklch(0.15 0.02 240 / 0.08);
  --shadow-md: 0 4px 12px oklch(0.15 0.02 240 / 0.12);
  --shadow-lg: 0 12px 32px oklch(0.15 0.02 240 / 0.18);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;

  /* Fonts */
  --font-display: 'Cabinet Grotesk', 'Helvetica Neue', sans-serif;
  --font-body:    'Satoshi', 'Inter', sans-serif;
  --font-mono:    'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* Code block surfaces */
  --color-code-bg:     #1e2030;
  --color-code-text:   #c0caf5;
  --color-code-border: #2a2d3e;
  --color-code-line-num: #565f89;
  --color-code-comment: #636da6;
  --color-code-keyword: #bb9af7;
  --color-code-string:  #9ece6a;
  --color-code-number:  #ff9e64;
  --color-code-func:    #7aa2f7;
  --color-code-op:      #89ddff;
}

[data-theme="dark"] {
  --color-bg:              #0d0f17;
  --color-surface:         #111420;
  --color-surface-2:       #161927;
  --color-surface-offset:  #1a1d2e;
  --color-surface-offset-2:#1e2236;
  --color-surface-dynamic: #252a3d;
  --color-divider:         #2a2f44;
  --color-border:          #323750;
  --color-text:            #c8cce0;
  --color-text-muted:      #6b7094;
  --color-text-faint:      #404560;
  --color-text-inverse:    #0d0f17;
  --color-primary:         #f59e0b;
  --color-primary-hover:   #fbbf24;
  --color-primary-active:  #fcd34d;
  --color-primary-highlight: #451a03;
  --color-indigo:          #818cf8;
  --color-violet:          #a78bfa;
  --color-rose:            #fb7185;
  --color-emerald:         #34d399;
  --color-sky:             #38bdf8;
  --color-success:         #34d399;
  --color-warning:         #fbbf24;
  --color-error:           #fb7185;
  --color-code-bg:         #0d0f17;
  --color-code-text:       #c0caf5;
  --color-code-border:     #1e2130;
  --shadow-sm: 0 1px 3px oklch(0 0 0 / 0.3);
  --shadow-md: 0 4px 12px oklch(0 0 0 / 0.4);
  --shadow-lg: 0 12px 32px oklch(0 0 0 / 0.5);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg:              #0d0f17;
    --color-surface:         #111420;
    --color-surface-2:       #161927;
    --color-surface-offset:  #1a1d2e;
    --color-surface-offset-2:#1e2236;
    --color-surface-dynamic: #252a3d;
    --color-divider:         #2a2f44;
    --color-border:          #323750;
    --color-text:            #c8cce0;
    --color-text-muted:      #6b7094;
    --color-text-faint:      #404560;
    --color-text-inverse:    #0d0f17;
    --color-primary:         #f59e0b;
    --color-primary-hover:   #fbbf24;
    --color-primary-active:  #fcd34d;
    --color-primary-highlight: #451a03;
    --color-indigo:          #818cf8;
    --color-violet:          #a78bfa;
    --color-rose:            #fb7185;
    --color-emerald:         #34d399;
    --color-sky:             #38bdf8;
    --color-code-bg:         #0d0f17;
    --color-code-text:       #c0caf5;
    --color-code-border:     #1e2130;
    --shadow-sm: 0 1px 3px oklch(0 0 0 / 0.3);
    --shadow-md: 0 4px 12px oklch(0 0 0 / 0.4);
    --shadow-lg: 0 12px 32px oklch(0 0 0 / 0.5);
  }
}

/* ============================================
   LAYOUT
   ============================================ */

.site-wrapper {
  display: grid;
  grid-template-rows: auto 1fr auto;
  min-height: 100dvh;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: oklch(from var(--color-bg) l c h / 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-divider);
  padding: var(--space-4) var(--space-8);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.header-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text);
}

.header-logo {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}

.header-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.header-subtitle {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: -2px;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.header-nav a {
  font-size: var(--text-sm);
  font-family: var(--font-body);
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-md);
}

.header-nav a:hover {
  color: var(--color-primary);
  background: var(--color-primary-highlight);
}

.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
}

.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-surface-dynamic);
}

/* Main layout: sidebar + content */
.main-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  max-width: var(--content-wide);
  margin: 0 auto;
  width: 100%;
  padding: var(--space-8) var(--space-6);
  gap: var(--space-8);
  align-items: start;
}

/* Sidebar TOC */
.sidebar {
  position: sticky;
  top: calc(60px + var(--space-6));
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
}

.sidebar-title {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.toc-list a {
  display: block;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  transition: all var(--transition-interactive);
}

.toc-list a:hover,
.toc-list a.active {
  color: var(--color-primary);
  background: var(--color-primary-highlight);
}

.sidebar-metrics {
  margin-top: var(--space-5);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-divider);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.metric-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.metric-value {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-primary);
}

/* Main content */
.main-content {
  min-width: 0;
}

/* Hero/intro */
.page-hero {
  padding: var(--space-8) 0 var(--space-6);
}

.page-hero h1 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  line-height: 1.1;
  margin-bottom: var(--space-2);
}

.page-hero .tagline {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.why-link {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: 1px dashed var(--color-primary);
  padding-bottom: 1px;
  transition: all var(--transition-interactive);
}

.why-link:hover {
  color: var(--color-primary-hover);
  border-bottom-style: solid;
}

/* ============================================
   PIPELINE STEPPER
   ============================================ */

.pipeline-section {
  margin-bottom: var(--space-8);
}

.pipeline-steps {
  display: flex;
  overflow-x: auto;
  gap: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  scrollbar-width: none;
}

.pipeline-steps::-webkit-scrollbar { display: none; }

.step-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  border-right: 1px solid var(--color-border);
  white-space: nowrap;
  flex-shrink: 0;
  position: relative;
  background: transparent;
  border-top: none;
  border-bottom: none;
  border-left: none;
  cursor: pointer;
  transition: all var(--transition-interactive);
}

.step-btn:last-child {
  border-right: none;
}

.step-btn.active {
  background: var(--color-primary);
  color: #fff;
}

.step-btn.active .step-num {
  background: rgba(255,255,255,0.2);
  color: #fff;
}

.step-btn:hover:not(.active) {
  background: var(--color-surface-offset);
  color: var(--color-text);
}

.step-num {
  width: 20px;
  height: 20px;
  border-radius: var(--radius-full);
  background: var(--color-surface-offset);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.step-arrow {
  color: var(--color-text-faint);
  font-size: 0.7rem;
  margin-left: auto;
}

/* Playback controls */
.playback-bar {
  background: var(--color-surface-offset);
  border-left: 1px solid var(--color-border);
  border-right: 1px solid var(--color-border);
  padding: var(--space-3) var(--space-4);
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.play-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  font-family: var(--font-body);
  transition: all var(--transition-interactive);
}

.play-btn:hover {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.progress-track {
  flex: 1;
  height: 6px;
  background: var(--color-border);
  border-radius: var(--radius-full);
  position: relative;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--color-primary);
  border-radius: var(--radius-full);
  transition: width 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.stage-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  white-space: nowrap;
}

/* View tabs */
.view-tabs {
  background: var(--color-surface);
  border-left: 1px solid var(--color-border);
  border-right: 1px solid var(--color-border);
  padding: var(--space-2) var(--space-4);
  display: flex;
  gap: var(--space-2);
}

.tab-btn {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-family: var(--font-body);
  font-weight: 500;
  color: var(--color-text-muted);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  transition: all var(--transition-interactive);
}

.tab-btn.active {
  background: var(--color-surface-2);
  color: var(--color-text);
  border-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.tab-btn:hover:not(.active) {
  color: var(--color-text);
  background: var(--color-surface-offset);
}

/* Stage viewer */
.stage-viewer {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-top: none;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  overflow: hidden;
}

/* Stage info panel */
.stage-info {
  padding: var(--space-5);
  background: var(--color-surface-offset);
  border-bottom: 1px solid var(--color-divider);
}

.stage-name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.stage-description {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  max-width: 80ch;
  margin-bottom: var(--space-4);
}

.ops-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.op-chip {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  font-weight: 500;
  border: 1px solid transparent;
}

.op-chip .dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
}

/* Metrics row */
.metrics-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--color-divider);
  border-bottom: 1px solid var(--color-divider);
}

.metric-card {
  background: var(--color-surface);
  padding: var(--space-4) var(--space-5);
}

.metric-card-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-2);
}

.metric-card-value {
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.metric-bar-track {
  height: 6px;
  background: var(--color-surface-offset);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.metric-bar-fill {
  height: 100%;
  border-radius: var(--radius-full);
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Split panel: code + operations */
.split-panel {
  display: grid;
  grid-template-columns: 1fr 240px;
  gap: 0;
}

/* Code panel */
.code-panel {
  border-right: 1px solid var(--color-divider);
}

.code-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  background: var(--color-code-bg);
  border-bottom: 1px solid var(--color-code-border);
}

.code-panel-title {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-code-line-num);
  text-transform: uppercase;
}

.traffic-lights {
  display: flex;
  gap: 6px;
  align-items: center;
}

.traffic-lights span {
  width: 10px;
  height: 10px;
  border-radius: var(--radius-full);
}

.copy-btn {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-code-line-num);
  padding: var(--space-1) var(--space-3);
  border: 1px solid var(--color-code-border);
  border-radius: var(--radius-sm);
  transition: all var(--transition-interactive);
}

.copy-btn:hover {
  color: var(--color-code-text);
  border-color: var(--color-code-text);
}

.code-block {
  background: var(--color-code-bg);
  padding: var(--space-5);
  overflow-x: auto;
  max-height: 380px;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--color-code-border) transparent;
}

.code-block pre {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.8;
  color: var(--color-code-text);
  margin: 0;
  counter-reset: line;
}

.code-line {
  display: flex;
  gap: var(--space-4);
  position: relative;
}

.code-line:hover {
  background: oklch(from var(--color-primary) l c h / 0.06);
  border-radius: var(--radius-sm);
}

.line-num {
  color: var(--color-code-line-num);
  user-select: none;
  min-width: 2ch;
  text-align: right;
  flex-shrink: 0;
}

.line-content {
  flex: 1;
  white-space: pre;
}

.op-marker {
  position: absolute;
  left: -16px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.55rem;
  font-weight: 800;
  color: white;
  font-family: var(--font-mono);
}

/* Syntax highlight classes */
.kw   { color: var(--color-code-keyword); }
.fn   { color: var(--color-code-func); }
.str  { color: var(--color-code-string); }
.num  { color: var(--color-code-number); }
.op   { color: var(--color-code-op); }
.cmt  { color: var(--color-code-comment); font-style: italic; }
.var  { color: #e0af68; }

/* Operations sidebar */
.ops-panel {
  padding: var(--space-4);
  background: var(--color-surface);
}

.ops-panel-title {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.ops-panel-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.op-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface-2);
  font-size: var(--text-sm);
  font-family: var(--font-body);
  color: var(--color-text);
  cursor: pointer;
  transition: all var(--transition-interactive);
}

.op-item:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-highlight);
}

.op-item.highlighted {
  border-color: var(--color-primary);
  background: var(--color-primary-highlight);
  box-shadow: var(--shadow-sm);
}

.op-badge {
  width: 22px;
  height: 22px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 800;
  color: white;
  font-family: var(--font-mono);
  flex-shrink: 0;
}

/* Graph panel */
.graph-panel {
  padding: var(--space-5);
  background: var(--color-surface);
  min-height: 400px;
  display: none;
}

.graph-panel.visible {
  display: block;
}

.ir-panel.hidden,
.graph-panel.hidden {
  display: none;
}

/* Attention visualization */
.attention-viz {
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  margin-bottom: var(--space-5);
  overflow-x: auto;
}

.attention-viz-title {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.attn-matrix {
  display: grid;
  gap: 2px;
}

.attn-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.6rem;
  font-weight: 600;
  transition: all 0.3s;
  cursor: pointer;
}

.attn-cell:hover {
  transform: scale(1.15);
  box-shadow: var(--shadow-md);
  z-index: 1;
}

/* ============================================
   CONTENT SECTIONS
   ============================================ */

.content-section {
  margin-bottom: var(--space-12);
}

.section-anchor {
  position: relative;
  top: -80px;
  visibility: hidden;
}

.section-heading {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-primary);
  display: inline-block;
}

.section-body {
  font-size: var(--text-base);
  color: var(--color-text);
  line-height: 1.75;
  max-width: 72ch;
}

.section-body p {
  margin-bottom: var(--space-5);
}

.section-body h3 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin: var(--space-8) 0 var(--space-3);
}

.section-body strong {
  color: var(--color-text);
  font-weight: 700;
}

.section-body code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-surface-offset);
  color: var(--color-primary);
  padding: 0.1em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
}

.inline-formula {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-1) var(--space-3);
  color: var(--color-primary);
  margin: 0 var(--space-1);
}

.formula-block {
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-primary);
  border-radius: var(--radius-md);
  padding: var(--space-5) var(--space-6);
  margin: var(--space-6) 0;
  font-family: var(--font-mono);
  font-size: var(--text-base);
  text-align: center;
  color: var(--color-text);
  letter-spacing: 0.02em;
}

.callout {
  background: var(--color-primary-highlight);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  margin: var(--space-6) 0;
}

.callout p {
  font-size: var(--text-sm);
  color: var(--color-text);
  margin: 0;
  max-width: 80ch;
}

.callout strong {
  color: var(--color-primary);
}

/* Diagram: Q/K/V boxes */
.qkv-diagram {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
  margin: var(--space-8) 0;
}

.qkv-box {
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  border: 1.5px solid;
  text-align: center;
}

.qkv-box .label {
  font-family: var(--font-mono);
  font-size: var(--text-xl);
  font-weight: 800;
  margin-bottom: var(--space-2);
}

.qkv-box .desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  max-width: none;
}

/* Footer */
.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-divider);
  padding: var(--space-6) var(--space-8);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.footer-left {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.footer-links {
  display: flex;
  gap: var(--space-5);
  align-items: center;
}

.footer-links a {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--color-primary);
}

/* ============================================
   GRAPH / ANIMATION VISUALIZATION
   ============================================ */

.flow-diagram {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-6) 0;
}

.flow-node {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.flow-box {
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  border: 1.5px solid;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 600;
  text-align: center;
  min-width: 180px;
  transition: all 0.3s;
}

.flow-arrow-down {
  width: 2px;
  height: 24px;
  background: var(--color-border);
  position: relative;
}

.flow-arrow-down::after {
  content: '▼';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 8px;
  color: var(--color-border);
}

.flow-parallel {
  display: flex;
  gap: var(--space-8);
  align-items: center;
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 900px) {
  .main-layout {
    grid-template-columns: 1fr;
    padding: var(--space-5) var(--space-4);
    gap: var(--space-5);
  }

  .sidebar {
    position: static;
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-4);
  }

  .toc-list {
    flex: 1;
    min-width: 140px;
  }

  .sidebar-metrics {
    border-top: none;
    border-left: 1px solid var(--color-divider);
    padding-top: 0;
    padding-left: var(--space-4);
    margin-top: 0;
    flex-shrink: 0;
  }

  .split-panel {
    grid-template-columns: 1fr;
  }

  .ops-panel {
    border-top: 1px solid var(--color-divider);
  }

  .metrics-row {
    grid-template-columns: 1fr;
  }

  .qkv-diagram {
    grid-template-columns: 1fr;
  }

  .site-header {
    padding: var(--space-3) var(--space-4);
  }

  .header-subtitle {
    display: none;
  }
}

@media (max-width: 600px) {
  .pipeline-steps {
    gap: 0;
  }

  .step-btn {
    padding: var(--space-2) var(--space-3);
    font-size: 0.7rem;
  }

  .site-footer {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-3);
  }
}

/* ============================================
   ANIMATION STATES
   ============================================ */

.stage-view {
  display: none;
}

.stage-view.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

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

.number-animate {
  display: inline-block;
  transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}