:root {
  --bg: #fafafa;
  --bg-elevated: #ffffff;
  --bg-panel: #ffffff;
  --border: #e4e4e7;
  --border-strong: #d4d4d8;
  --text: #18181b;
  --text-muted: #71717a;
  --text-subtle: #a1a1aa;
  --accent: #18181b;
  --accent-hover: #27272a;
  --accent-dim: #f4f4f5;
  --link: #2563eb;
  --link-hover: #1d4ed8;
  --score: #059669;
  --external: #2563eb;
  --external-bg: #eff6ff;
  --internal-bg: #f4f4f5;
  --radius: 10px;
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", monospace;
}

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

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

/* —— Top nav (DeepSWE-style) —— */
.topnav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0.625rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: var(--bg-elevated);
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--text);
  text-decoration: none;
}

.brand-logo {
  display: block;
  width: 24px;
  height: 24px;
  border-radius: 6px;
  object-fit: cover;
  flex-shrink: 0;
}

.brand-logo-lg {
  width: 56px;
  height: 56px;
  border-radius: 10px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}

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

.nav-github {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.page {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.5rem 2.5rem;
}

.hero {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 1.75rem 0 1.25rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1.25rem;
}

.hero-brand {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.hero h1 {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.hero-byline {
  margin-top: 0.25rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(2, auto);
  gap: 0.75rem 2rem;
  font-family: var(--mono);
  font-size: 0.8125rem;
}

.hero-stats div {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1.5rem;
  align-items: baseline;
}

.hero-stats dt {
  color: var(--text-muted);
  font-weight: 400;
}

.hero-stats dd {
  font-weight: 600;
  color: var(--text);
  text-align: right;
}

.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-bottom: 0.875rem;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.panel-compact {
  padding: 1rem 1.125rem;
}

.section-title-sm {
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 0.625rem;
}

.panel h2 {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.panel-desc {
  color: var(--text-muted);
  font-size: 0.9375rem;
  margin-top: 0.25rem;
}

.panel-header { margin-bottom: 0.75rem; }

.controls-block {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.control-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
}

.control-label {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-subtle);
  min-width: 4.5rem;
}

.control-hint {
  display: none;
}

.task-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  background: var(--accent-dim);
  padding: 0.2rem;
  border-radius: 8px;
  border: 1px solid var(--border);
}

.task-tab {
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font);
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.4rem 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, box-shadow 0.15s;
  text-align: left;
  line-height: 1.3;
}

.task-tab .tab-id {
  display: block;
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 600;
}

.task-tab .tab-name {
  display: block;
  font-size: 0.6875rem;
  font-weight: 400;
  color: var(--text-subtle);
  margin-top: 0.1rem;
}

.task-tab.active .tab-name { color: var(--text-muted); }

.task-tab:hover { color: var(--text); }

.task-tab.active {
  background: var(--bg-elevated);
  color: var(--text);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.06);
}

.metric-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
}

.metric-btn {
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  font-family: var(--font);
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.35rem 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}

.metric-btn:hover {
  border-color: var(--border-strong);
  color: var(--text);
}

.metric-btn.active {
  border-color: var(--text);
  color: var(--text);
  background: var(--accent-dim);
}

/* —— Chart —— */
.chart-section {
  margin-bottom: 1rem;
}

.chart-wrap {
  position: relative;
  height: 260px;
  background: var(--bg);
  border-radius: 8px;
  padding: 1rem 1rem 0.5rem;
  border: 1px solid var(--border);
}

.chart-caption {
  font-size: 0.8125rem;
  color: var(--text-muted);
  text-align: left;
  margin-top: 0.75rem;
  padding-left: 0.25rem;
  line-height: 1.45;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
}

.rank-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  background: var(--bg-elevated);
}

.rank-table th {
  text-align: left;
  padding: 0.625rem 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  white-space: nowrap;
  background: var(--bg);
}

.rank-table th:hover { color: var(--text); }

.rank-table td {
  padding: 0.75rem;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}

.rank-table tbody tr:last-child td { border-bottom: none; }
.rank-table tbody tr:hover { background: #fafafa; }

.rank-num {
  font-family: var(--mono);
  color: var(--text-subtle);
  font-size: 0.8125rem;
}

.loop-name { font-weight: 500; }
.submitter { color: var(--text-muted); font-size: 0.8125rem; }

.badge {
  display: inline-block;
  font-size: 0.625rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.125rem 0.375rem;
  border-radius: 4px;
  margin-left: 0.35rem;
}

.badge.external { background: var(--external-bg); color: var(--external); }
.badge.internal { background: var(--internal-bg); color: var(--text-muted); }

.les-cell {
  font-family: var(--mono);
  font-weight: 600;
  color: var(--score);
}

.spec-link {
  color: var(--link);
  text-decoration: none;
  font-size: 0.8125rem;
  font-weight: 500;
}
.spec-link:hover { text-decoration: underline; }

/* —— Glossary & features —— */
.glossary-compact {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.375rem 1.25rem;
  margin-top: 0;
}

.glossary-compact div {
  display: grid;
  grid-template-columns: 5.5rem 1fr;
  gap: 0.5rem;
  padding-bottom: 0.375rem;
}

.glossary-compact dt {
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 600;
}

.glossary-compact dd {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.feature-grid-compact {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
  margin-top: 0;
}

.feature-grid-compact .feature {
  padding: 0.625rem 0.75rem;
}

.feature-grid-compact .feature h3 {
  font-size: 0.8125rem;
  margin-bottom: 0.2rem;
}

.feature-grid-compact .feature p {
  font-size: 0.75rem;
  line-height: 1.4;
}

.feature {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
}

.feature h3 { font-weight: 600; }
.feature p { color: var(--text-muted); }

/* —— Task cards —— */
.task-cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
  margin-top: 0;
}

.task-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.5rem 0.625rem;
  cursor: pointer;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.task-card:hover { border-color: var(--border-strong); }

.task-card.active {
  border-color: var(--text);
  box-shadow: 0 0 0 1px var(--text);
  background: var(--bg-elevated);
}

.task-card-head {
  display: flex;
  align-items: baseline;
  gap: 0.35rem;
  flex-wrap: wrap;
}

.task-card-id {
  font-family: var(--mono);
  font-size: 0.625rem;
  color: var(--text-subtle);
  font-weight: 600;
  letter-spacing: 0.02em;
}

.task-card-title {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.2;
}

.task-card-desc {
  font-size: 0.6875rem;
  color: var(--text-muted);
  line-height: 1.35;
  margin-top: 0.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.code-block {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  overflow-x: auto;
  margin: 0.625rem 0;
  font-family: var(--mono);
  font-size: 0.75rem;
  line-height: 1.55;
}

.cta-section p {
  font-size: 0.8125rem;
  margin-top: 0.375rem;
}

.cta-section a {
  color: var(--link);
  font-weight: 500;
  text-decoration: none;
}

.cta-section a:hover { text-decoration: underline; }

.site-footer {
  text-align: center;
  padding: 1.25rem 0 0.5rem;
  color: var(--text-subtle);
  font-size: 0.8125rem;
  border-top: 1px solid var(--border);
}

.site-footer a { color: var(--text-muted); text-decoration: none; }
.site-footer a:hover { color: var(--text); }

@media (max-width: 900px) {
  .task-cards { grid-template-columns: repeat(2, 1fr); }
  .feature-grid-compact { grid-template-columns: 1fr; }
  .glossary-compact { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .topnav { flex-wrap: wrap; gap: 0.75rem; }
  .nav-links { flex-wrap: wrap; gap: 0.75rem; }
  .hero { flex-direction: column; }
  .task-cards { grid-template-columns: 1fr; }
}