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

:root {
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-card: #1c2129;
  --bg-card-hover: #22272e;
  --border-color: #30363d;
  --text-primary: #e6edf3;
  --text-secondary: #8b949e;
  --text-muted: #6e7681;
  --accent-blue: #58a6ff;
  --accent-green: #3fb950;
  --accent-orange: #d29922;
  --accent-red: #f85149;
  --accent-purple: #bc8cff;
  --accent-cyan: #39d2c0;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;
  --max-width: 1200px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

a {
  color: var(--accent-blue);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

/* ===== Navigation ===== */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 0 2rem;
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  height: 64px;
  gap: 2rem;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-logo .logo-mark {
  color: var(--accent-cyan);
  font-family: var(--font-mono);
  font-size: 1.4rem;
}

.nav-links {
  display: flex;
  gap: 0.25rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.15s, background 0.15s;
}

.nav-links a:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.05);
  text-decoration: none;
}

.nav-links a.active {
  color: var(--text-primary);
  background: rgba(255,255,255,0.08);
}

/* ===== Hero Section ===== */
.hero {
  padding: 6rem 2rem 4rem;
  text-align: center;
  max-width: var(--max-width);
  margin: 0 auto;
}

.hero-badge {
  display: inline-block;
  background: rgba(57, 210, 192, 0.1);
  color: var(--accent-cyan);
  border: 1px solid rgba(57, 210, 192, 0.25);
  padding: 0.35rem 1rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
}

.hero h1 .highlight {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-subtitle {
  font-size: 1.3rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 2.5rem;
  line-height: 1.6;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

.stat {
  text-align: center;
}

.stat-number {
  font-size: 2rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--accent-cyan);
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: 0.25rem;
}

/* ===== Section Layout ===== */
section {
  padding: 4rem 2rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent-cyan);
  margin-bottom: 0.75rem;
}

section h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

section .section-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin-bottom: 2.5rem;
}

/* ===== Divider ===== */
.divider {
  max-width: var(--max-width);
  margin: 0 auto;
  border: none;
  border-top: 1px solid var(--border-color);
}

/* ===== Problem / Solution ===== */
.problem-solution {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 2rem;
}

.problem-card, .solution-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2rem;
}

.problem-card {
  border-left: 3px solid var(--accent-red);
}

.solution-card {
  border-left: 3px solid var(--accent-green);
}

.problem-card h3, .solution-card h3 {
  font-size: 1.1rem;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.problem-card ul, .solution-card ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.problem-card li, .solution-card li {
  font-size: 0.95rem;
  color: var(--text-secondary);
  padding-left: 1.5rem;
  position: relative;
}

.problem-card li::before {
  content: "\2717";
  position: absolute;
  left: 0;
  color: var(--accent-red);
  font-weight: 700;
}

.solution-card li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--accent-green);
  font-weight: 700;
}

/* ===== Feature Cards Grid ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.75rem;
  transition: border-color 0.2s, background 0.2s;
}

.feature-card:hover {
  border-color: rgba(88, 166, 255, 0.3);
  background: var(--bg-card-hover);
}

.feature-icon {
  font-size: 1.75rem;
  margin-bottom: 1rem;
}

.feature-card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ===== Use Cases ===== */
.use-cases-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.use-case {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2rem;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.5rem;
  transition: border-color 0.2s;
}

.use-case:hover {
  border-color: rgba(88, 166, 255, 0.3);
}

.use-case-number {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent-cyan);
  opacity: 0.5;
  width: 3rem;
  text-align: center;
  padding-top: 0.15rem;
}

.use-case h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.use-case-scenario {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  font-style: italic;
}

.use-case-why {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.use-case-why strong {
  color: var(--accent-green);
  font-weight: 600;
}

/* ===== Comparison Table ===== */
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1.5rem;
  font-size: 0.9rem;
}

.comparison-table th {
  text-align: left;
  padding: 0.75rem 1rem;
  border-bottom: 2px solid var(--border-color);
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.comparison-table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
}

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

.comparison-table td:first-child {
  color: var(--text-primary);
  font-weight: 500;
}

.check {
  color: var(--accent-green);
}

.cross {
  color: var(--accent-red);
}

/* ===== Timeline ===== */
.timeline {
  position: relative;
  margin-top: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 1.5rem;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border-color);
}

.timeline-item {
  position: relative;
  padding-left: 4rem;
  padding-bottom: 2rem;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: 1rem;
  top: 0.25rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-cyan);
  border: 2px solid var(--bg-primary);
}

.timeline-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.timeline-phase {
  font-size: 0.75rem;
  color: var(--accent-cyan);
  font-family: var(--font-mono);
  margin-bottom: 0.25rem;
}

.timeline-item p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* ===== Code Block ===== */
.code-block {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin: 1.5rem 0;
}

.code-block .comment { color: var(--text-muted); }
.code-block .key { color: var(--accent-blue); }
.code-block .string { color: var(--accent-green); }
.code-block .number { color: var(--accent-orange); }

/* ===== Quote / Callout ===== */
.callout {
  background: var(--bg-card);
  border-left: 3px solid var(--accent-cyan);
  border-radius: 0 8px 8px 0;
  padding: 1.5rem 2rem;
  margin: 2rem 0;
}

.callout p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  font-style: italic;
  line-height: 1.6;
}

.callout .attribution {
  margin-top: 0.75rem;
  font-size: 0.85rem;
  font-style: normal;
  color: var(--text-muted);
}

/* ===== Footer ===== */
footer {
  border-top: 1px solid var(--border-color);
  padding: 2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 4rem;
}

/* ===== Empty Page State ===== */
.empty-page {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  text-align: center;
  padding: 4rem 2rem;
}

.empty-page h2 {
  font-size: 2rem;
  margin-bottom: 1rem;
}

.empty-page p {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* ===== Test Results Page ===== */

/* Model tags */
.model-tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 12px;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.model-tag.cloud {
  background: rgba(88, 166, 255, 0.15);
  color: var(--accent-blue);
  border: 1px solid rgba(88, 166, 255, 0.3);
}

.model-tag.local {
  background: rgba(188, 140, 255, 0.15);
  color: var(--accent-purple);
  border: 1px solid rgba(188, 140, 255, 0.3);
}

/* Rank badges */
.rank-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  font-weight: 800;
  font-size: 0.8rem;
  font-family: var(--font-mono);
}

.rank-gold {
  background: rgba(210, 153, 34, 0.2);
  color: var(--accent-orange);
  border: 1px solid rgba(210, 153, 34, 0.4);
}

.rank-silver {
  background: rgba(139, 148, 158, 0.15);
  color: var(--text-secondary);
  border: 1px solid rgba(139, 148, 158, 0.3);
}

.rank-bronze {
  background: rgba(188, 140, 255, 0.12);
  color: var(--accent-purple);
  border: 1px solid rgba(188, 140, 255, 0.25);
}

/* Score colors */
.score-high { color: var(--accent-green); }
.score-mid { color: var(--accent-blue); }
.score-low { color: var(--accent-orange); }
.score-detail {
  font-weight: 400;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Tier badges */
.tier-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 6px;
  font-weight: 700;
  font-size: 0.75rem;
  font-family: var(--font-mono);
}

.tier-badge.t1 {
  background: rgba(63, 185, 80, 0.15);
  color: var(--accent-green);
}

.tier-badge.t2 {
  background: rgba(88, 166, 255, 0.15);
  color: var(--accent-blue);
}

.tier-badge.t3 {
  background: rgba(210, 153, 34, 0.15);
  color: var(--accent-orange);
}

.tier-badge.t4 {
  background: rgba(188, 140, 255, 0.15);
  color: var(--accent-purple);
}

/* Task matrix */
.matrix-scroll {
  overflow-x: auto;
  margin: 0 -1rem;
  padding: 0 1rem;
}

.task-matrix {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  white-space: nowrap;
}

.task-matrix th {
  text-align: center;
  padding: 0.6rem 0.75rem;
  border-bottom: 2px solid var(--border-color);
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.task-matrix th.task-col {
  text-align: left;
  min-width: 180px;
}

.task-matrix th.tier-col {
  min-width: 50px;
}

.task-matrix td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--border-color);
  text-align: center;
  color: var(--text-secondary);
}

.task-matrix td:first-child {
  text-align: left;
  color: var(--text-primary);
  font-weight: 500;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.task-matrix td:nth-child(2) {
  text-align: center;
}

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

.task-matrix .pass {
  color: var(--accent-green);
  font-weight: 700;
  font-size: 1rem;
}

.task-matrix .fail {
  color: var(--accent-red);
  font-weight: 600;
  font-size: 0.75rem;
  background: rgba(248, 81, 73, 0.08);
  border-radius: 4px;
}

.tier-header td {
  background: var(--bg-secondary);
  color: var(--text-muted) !important;
  font-weight: 700 !important;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.75rem;
  text-align: left !important;
  border-bottom: 1px solid var(--border-color);
  font-family: var(--font-sans) !important;
}

/* Legend */
.legend {
  display: flex;
  gap: 1.5rem;
  margin-top: 1.25rem;
  flex-wrap: wrap;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.legend .pass {
  color: var(--accent-green);
  font-weight: 600;
}

.fail-legend {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.fail-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 3px;
}

.fail-dot.sem { background: var(--accent-red); opacity: 0.9; }
.fail-dot.ref { background: var(--accent-orange); }
.fail-dot.val { background: var(--accent-blue); }
.fail-dot.sch { background: var(--accent-purple); }
.fail-dot.run { background: var(--accent-red); opacity: 0.5; }

/* Code inline */
code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--bg-secondary);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  color: var(--accent-cyan);
}

/* ===== Documentation Page ===== */
.docs-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  max-width: 1400px;
  margin: 0 auto;
  min-height: calc(100vh - 64px);
}

/* Sidebar */
.docs-sidebar {
  position: sticky;
  top: 64px;
  height: calc(100vh - 64px);
  overflow-y: auto;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  padding: 1.5rem 0;
  scrollbar-width: thin;
  scrollbar-color: var(--border-color) transparent;
}

.docs-sidebar::-webkit-scrollbar {
  width: 6px;
}

.docs-sidebar::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

.docs-sidebar-group {
  margin-bottom: 0.5rem;
}

.docs-sidebar-heading {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  padding: 0.5rem 1.25rem 0.35rem;
  user-select: none;
}

.docs-sidebar a {
  display: block;
  font-size: 0.82rem;
  color: var(--text-secondary);
  padding: 0.35rem 1.25rem 0.35rem 1.75rem;
  border-left: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
  text-decoration: none;
  line-height: 1.4;
}

.docs-sidebar a:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.03);
  text-decoration: none;
}

.docs-sidebar a.active {
  color: var(--accent-cyan);
  border-left-color: var(--accent-cyan);
  background: rgba(57, 210, 192, 0.05);
  font-weight: 600;
}

/* Main content */
.docs-content {
  padding: 2.5rem 3rem 4rem;
  max-width: 900px;
  overflow-x: hidden;
}

.docs-content .doc-section {
  display: none;
  animation: docFadeIn 0.2s ease;
}

.docs-content .doc-section.active {
  display: block;
}

@keyframes docFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.docs-content h1 {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
  line-height: 1.2;
}

.docs-content h1 .highlight {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.docs-content .doc-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  line-height: 1.6;
}

.docs-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
  letter-spacing: -0.01em;
}

.docs-content h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-top: 1.75rem;
  margin-bottom: 0.5rem;
  color: var(--accent-blue);
}

.docs-content h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-top: 1.25rem;
  margin-bottom: 0.35rem;
}

.docs-content p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 1rem;
}

.docs-content ul, .docs-content ol {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}

.docs-content li {
  font-size: 0.93rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0.35rem;
}

.docs-content li strong {
  color: var(--text-primary);
}

.docs-content strong {
  color: var(--text-primary);
  font-weight: 600;
}

.docs-content em {
  color: var(--text-secondary);
}

/* Doc tables */
.doc-table-wrap {
  overflow-x: auto;
  margin: 1rem 0 1.5rem;
}

.doc-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}

.doc-table th {
  text-align: left;
  padding: 0.6rem 0.75rem;
  border-bottom: 2px solid var(--border-color);
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.doc-table td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
  vertical-align: top;
}

.doc-table td:first-child {
  color: var(--text-primary);
  font-weight: 500;
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

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

.doc-table tr:hover td {
  background: rgba(255,255,255,0.02);
}

/* Phase card */
.phase-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 1.75rem;
  margin-bottom: 1.5rem;
  transition: border-color 0.2s;
}

.phase-card:hover {
  border-color: rgba(57, 210, 192, 0.25);
}

.phase-card h3 {
  color: var(--accent-cyan);
  margin-top: 0;
  font-size: 1.1rem;
}

.phase-card .phase-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  font-family: var(--font-mono);
}

.phase-card p, .phase-card li {
  font-size: 0.9rem;
}

/* Doc code blocks */
.doc-code {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.65;
  color: var(--text-secondary);
  margin: 1rem 0 1.5rem;
  white-space: pre;
}

/* Architecture diagram */
.arch-diagram {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 1.5rem;
  margin: 1.5rem 0;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.7;
  color: var(--text-secondary);
  overflow-x: auto;
  white-space: pre;
  text-align: center;
}

.arch-diagram .arch-highlight {
  color: var(--accent-cyan);
  font-weight: 600;
}

/* Opcode grid */
.opcode-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 0.5rem;
  margin: 1rem 0 1.5rem;
}

.opcode-chip {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.4rem 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-secondary);
  text-align: center;
  transition: border-color 0.15s, color 0.15s;
}

.opcode-chip:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

/* Stat cards for overview */
.doc-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin: 1.5rem 0 2rem;
}

.doc-stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 1.25rem;
  text-align: center;
}

.doc-stat-card .stat-number {
  font-size: 1.8rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--accent-cyan);
}

.doc-stat-card .stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: 0.25rem;
}

/* Principle cards */
.principle-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 1.5rem 0;
}

.principle-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 1.5rem;
}

.principle-card h4 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-top: 0;
  margin-bottom: 0.5rem;
  color: var(--accent-cyan);
}

.principle-card p {
  font-size: 0.88rem;
  margin-bottom: 0;
}

/* ===== Responsive ===== */
@media (max-width: 1100px) {
  .docs-layout {
    grid-template-columns: 220px 1fr;
  }
  .docs-content {
    padding: 2rem 2rem 3rem;
  }
}

@media (max-width: 900px) {
  .hero h1 { font-size: 2.5rem; }
  .features-grid { grid-template-columns: 1fr; }
  .problem-solution { grid-template-columns: 1fr; }
  .hero-stats { gap: 1.5rem; }
  .nav-inner { gap: 1rem; }
  .task-matrix { font-size: 0.75rem; }
  .task-matrix th, .task-matrix td { padding: 0.4rem 0.5rem; }
  .legend { gap: 1rem; }
  .docs-layout { grid-template-columns: 1fr; }
  .docs-sidebar {
    position: relative;
    top: 0;
    height: auto;
    max-height: 50vh;
    border-right: none;
    border-bottom: 1px solid var(--border-color);
  }
  .doc-stats { grid-template-columns: repeat(2, 1fr); }
  .principle-grid { grid-template-columns: 1fr; }
  .docs-content { padding: 1.5rem 1rem 3rem; }
}

@media (max-width: 600px) {
  .hero h1 { font-size: 2rem; }
  .hero-subtitle { font-size: 1.05rem; }
  nav { padding: 0 1rem; }
  section { padding: 3rem 1rem; }
  .use-case { grid-template-columns: 1fr; }
  .use-case-number { display: none; }
}