/* PATSTAT Explorer — Design System
   Inspired by patentreports.depa.tech */

/* ============================================================
   CSS Custom Properties
   ============================================================ */
:root {
  --color-bg: #f4f5f7;
  --color-bg-dark: #0f172a;
  --color-bg-hero: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0d1f3c 100%);
  --color-teal: #14b8a6;
  --color-teal-light: #2dd4bf;
  --color-teal-dark: #0d9488;
  --color-teal-glow: rgba(20, 184, 166, 0.12);
  --color-white: #ffffff;
  --color-gray-50: #f4f5f7;
  --color-gray-100: #f1f5f9;
  --color-gray-200: #e2e8f0;
  --color-gray-300: #cbd5e1;
  --color-gray-400: #94a3b8;
  --color-gray-500: #64748b;
  --color-gray-600: #475569;
  --color-gray-700: #334155;
  --color-gray-800: #1e293b;
  --color-gray-900: #0f172a;

  --color-overview: #6b7280;
  --color-trends: #14b8a6;
  --color-regional: #3b82f6;
  --color-technology: #8b5cf6;
  --color-performance: #e63946;
  --color-collaboration: #f59e0b;

  --color-patlib: #6366f1;
  --color-business: #059669;
  --color-university: #d97706;

  --font-serif: 'Source Serif 4', Georgia, serif;
  --font-sans: 'Inter', -apple-system, system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --container-width: 1200px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.02);
  --shadow-card-hover: 0 2px 8px rgba(0,0,0,0.08), 0 8px 24px rgba(0,0,0,0.04);
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
}

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

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-gray-800);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }

/* ============================================================
   Hero — matches patentreports.depa.tech exactly
   ============================================================ */
.hero {
  background: linear-gradient(135deg, var(--color-gray-900) 0%, var(--color-gray-800) 50%, #0d1f3c 100%);
  color: white;
  padding: 64px 48px 72px;
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: '';
  position: absolute;
  top: -40%;
  right: -15%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, var(--color-teal-glow) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero-content {
  max-width: var(--container-width);
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero .brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
  text-decoration: none;
}

.hero .brand img {
  height: 32px;
  width: auto;
  filter: brightness(0) invert(1);
}

.hero .brand .brand-text {
  font-family: var(--font-mono);
  font-size: 0.75em;
  letter-spacing: 0.05em;
  color: var(--color-gray-400);
  line-height: 1.4;
}

.hero .brand .brand-text strong {
  color: #e2e8f0;
  font-weight: 600;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: 2.8em;
  font-weight: 700;
  letter-spacing: -0.5px;
  line-height: 1.1;
  margin-bottom: 16px;
}

.hero .tagline {
  font-size: 1.15em;
  color: var(--color-gray-400);
  font-weight: 300;
  max-width: 600px;
  margin-bottom: 36px;
}

.hero .meta-row {
  display: flex;
  gap: 28px;
  font-family: var(--font-mono);
  font-size: 0.78em;
  color: var(--color-gray-400);
}

.hero .meta-row span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.hero .meta-row .pip {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--color-teal);
}

/* ============================================================
   Container
   ============================================================ */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 48px;
}

/* ============================================================
   Filters
   ============================================================ */
.filters {
  padding: 2rem 0 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.search-input {
  width: 100%;
  max-width: 480px;
  padding: 0.625rem 1rem;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  background: var(--color-white);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-input:focus {
  outline: none;
  border-color: var(--color-teal);
  box-shadow: 0 0 0 3px rgba(20,184,166,0.1);
}

.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.pill {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.875rem;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.03em;
  cursor: pointer;
  border: 1px solid var(--color-gray-200);
  background: var(--color-white);
  color: var(--color-gray-600);
  transition: all 0.2s;
}

.pill:hover { border-color: var(--color-teal); color: var(--color-teal); }

.pill.active { background: var(--color-teal); color: var(--color-white); border-color: var(--color-teal); }

.pill[data-category="Overview"].active       { background: var(--color-overview);       border-color: var(--color-overview); }
.pill[data-category="Trends"].active         { background: var(--color-trends);         border-color: var(--color-trends); }
.pill[data-category="Regional"].active       { background: var(--color-regional);       border-color: var(--color-regional); }
.pill[data-category="Technology"].active     { background: var(--color-technology);     border-color: var(--color-technology); }
.pill[data-category="Performance"].active    { background: var(--color-performance);    border-color: var(--color-performance); }
.pill[data-category="Collaboration"].active  { background: var(--color-collaboration);  border-color: var(--color-collaboration); }

/* ============================================================
   Tags & Badges
   ============================================================ */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.68em;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.tag-PATLIB     { background: rgba(99,102,241,0.1);  color: var(--color-patlib); }
.tag-BUSINESS   { background: rgba(5,150,105,0.1);   color: var(--color-business); }
.tag-UNIVERSITY { background: rgba(217,119,6,0.1);   color: var(--color-university); }
.tag-tip        { background: rgba(20,184,166,0.1);   color: var(--color-teal); }

.category-badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 10px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.02em;
}

.category-Overview        { background: rgba(107,114,128,0.1);  color: var(--color-overview); }
.category-Trends          { background: rgba(20,184,166,0.1);   color: var(--color-trends); }
.category-Regional        { background: rgba(59,130,246,0.1);   color: var(--color-regional); }
.category-Technology      { background: rgba(139,92,246,0.1);   color: var(--color-technology); }
.category-Performance     { background: rgba(230,57,70,0.1);    color: var(--color-performance); }
.category-Collaboration   { background: rgba(245,158,11,0.1);   color: var(--color-collaboration); }

/* ============================================================
   Query Count
   ============================================================ */
.query-count {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-gray-400);
}

/* ============================================================
   Query Cards (Landing Page)
   ============================================================ */
.query-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
  gap: 16px;
  padding-bottom: 4rem;
}

.query-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 32px 36px;
  cursor: pointer;
  transition: all 0.25s ease;
  display: block;
  box-shadow: var(--shadow-card);
}

.query-card:hover {
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-teal);
  transform: translateY(-2px);
}

.query-card .card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.5rem;
}

.query-card .card-id {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-gray-400);
}

.query-card h3 {
  font-family: var(--font-serif);
  font-size: 1.3em;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 0.5rem;
  color: var(--color-gray-800);
}

.query-card .card-description {
  font-size: 0.9em;
  color: var(--color-gray-500);
  line-height: 1.55;
  margin-bottom: 1rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.query-card .card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.query-card .card-tags { display: flex; gap: 0.25rem; flex-wrap: wrap; }

.query-card .card-arrow {
  color: var(--color-gray-300);
  transition: all 0.2s;
  font-size: 1.25rem;
}

.query-card:hover .card-arrow { color: var(--color-teal); transform: translateX(4px); }

/* ============================================================
   CTA Section — copied from patentreports.depa.tech
   ============================================================ */
.cta {
  max-width: var(--container-width);
  margin: 0 auto 0;
  padding: 0 48px 48px;
}

.cta-card {
  background: linear-gradient(135deg, var(--color-gray-900), var(--color-gray-800));
  border-radius: 12px;
  padding: 40px 44px;
  color: #e2e8f0;
}

.cta-card h3 {
  font-family: var(--font-serif);
  font-size: 1.25em;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 14px;
}

.cta-card p {
  font-size: 0.92em;
  line-height: 1.7;
  margin-bottom: 12px;
  color: #cbd5e1;
}

.cta-offerings {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin: 20px 0 24px;
}

.cta-offer {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 8px;
  padding: 20px;
}

.cta-offer strong {
  display: block;
  color: var(--color-teal);
  font-size: 0.88em;
  font-family: var(--font-mono);
  margin-bottom: 6px;
  letter-spacing: 0.02em;
}

.cta-offer span {
  font-size: 0.88em;
  color: #94a3b8;
  line-height: 1.6;
}

.cta-links {
  display: flex;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
}

.cta-links a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.82em;
  color: var(--color-teal);
  text-decoration: none;
  padding: 6px 14px;
  border: 1px solid rgba(20,184,166,0.3);
  border-radius: 6px;
  transition: background 0.15s, border-color 0.15s;
}

.cta-links a:hover {
  background: rgba(20,184,166,0.1);
  border-color: var(--color-teal);
}

.cta-links a svg {
  width: 14px; height: 14px;
  fill: currentColor;
}

@media (max-width: 768px) {
  .cta { padding: 0 20px 32px; }
  .cta-card { padding: 28px 24px; }
  .cta-offerings { grid-template-columns: 1fr; }
}

/* ============================================================
   Query Detail — Navigation
   ============================================================ */
.query-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 2rem;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
}

.query-nav .back-link {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--color-teal);
  display: flex;
  align-items: center;
  gap: 0.25rem;
  transition: color 0.2s;
}

.query-nav .back-link:hover { color: var(--color-teal-dark); }

.query-nav .nav-id {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-gray-400);
}

/* ============================================================
   Query Detail — Header & Explanation
   ============================================================ */
.query-header {
  padding: 2rem 0 1.5rem;
}

.query-header h1 {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--color-gray-900);
}

.query-header .meta {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}

.query-header .description {
  font-size: 1rem;
  color: var(--color-gray-500);
  line-height: 1.6;
}

.query-explanation {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  line-height: 1.7;
  color: var(--color-gray-600);
}

.query-explanation h3 {
  font-family: var(--font-serif);
  color: var(--color-gray-800);
  margin-bottom: 0.75rem;
  font-size: 1.125rem;
}

.query-explanation p { margin-bottom: 0.5rem; }

.query-explanation ul {
  margin: 0.5rem 0 0 1.25rem;
  list-style: disc;
}

.query-explanation li {
  font-size: 0.875rem;
  color: var(--color-gray-500);
  padding: 2px 0;
}

.key-outputs {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-gray-100);
}

.key-outputs-title {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-gray-400);
  margin-bottom: 0.5rem;
}

.key-outputs li {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-gray-500);
  padding: 2px 0;
}

/* ============================================================
   Query Detail — Workspace (SQL + Parameters)
   ============================================================ */
.workspace {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 1.25rem;
  margin-bottom: 1.5rem;
}

.sql-panel {
  background: var(--color-gray-900);
  border-radius: var(--radius-lg);
  overflow: hidden;
  min-width: 0;
}

.sql-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.625rem 1rem;
  background: rgba(255,255,255,0.05);
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.sql-header h2 {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-gray-400);
  font-weight: 400;
  letter-spacing: 0.05em;
}

.btn-copy {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 4px 12px;
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-gray-400);
  cursor: pointer;
  transition: all 0.2s;
}

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

.sql-code {
  padding: 1rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--color-gray-300);
  white-space: pre;
  tab-size: 2;
}

/* SQL syntax classes */
.sql-keyword  { color: #c084fc; font-weight: 500; }
.sql-function { color: #38bdf8; }
.sql-string   { color: #86efac; }
.sql-number   { color: #fbbf24; }
.sql-comment  { color: #64748b; font-style: italic; }
.sql-table    { color: #f0abfc; }
.sql-param {
  color: #2dd4bf;
  background: rgba(20,184,166,0.15);
  padding: 1px 5px;
  border-radius: 3px;
  font-weight: 600;
}

/* ============================================================
   Parameters Panel
   ============================================================ */
.params-panel {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  align-self: start;
}

.params-panel h3 {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  margin-bottom: 1rem;
  color: var(--color-gray-800);
}

.params-empty {
  color: var(--color-gray-400);
  font-size: 0.875rem;
  font-style: italic;
}

.param-group {
  margin-bottom: 1rem;
}

.param-group:last-child { margin-bottom: 0; }

.param-group label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-gray-500);
  margin-bottom: 0.375rem;
  letter-spacing: 0.03em;
}

.param-group input[type="text"],
.param-group select {
  width: 100%;
  padding: 0.5rem 0.625rem;
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  background: var(--color-white);
  transition: border-color 0.2s;
}

.param-group input:focus,
.param-group select:focus {
  outline: none;
  border-color: var(--color-teal);
  box-shadow: 0 0 0 3px rgba(20,184,166,0.1);
}

/* Range sliders */
.range-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.25rem;
}

.range-row .range-label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--color-gray-400);
  min-width: 2rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.range-row input[type="range"] {
  flex: 1;
  -webkit-appearance: none;
  height: 4px;
  border-radius: 2px;
  background: var(--color-gray-200);
  outline: none;
}

.range-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--color-teal);
  cursor: pointer;
  border: 2px solid var(--color-white);
  box-shadow: var(--shadow-sm);
}

.range-values {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-teal);
  font-weight: 500;
}

/* Multiselect */
.multiselect-container {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.multiselect-option {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  cursor: pointer;
  border: 1px solid var(--color-gray-200);
  background: var(--color-gray-50);
  color: var(--color-gray-600);
  transition: all 0.15s;
  user-select: none;
}

.multiselect-option:hover { border-color: var(--color-teal); }

.multiselect-option.selected {
  background: var(--color-teal);
  color: var(--color-white);
  border-color: var(--color-teal);
}

/* ============================================================
   Run Button & Actions
   ============================================================ */
.actions {
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.btn-run {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1.75rem;
  background: var(--color-teal);
  color: var(--color-white);
  border: none;
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.2s;
  letter-spacing: 0.03em;
}

.btn-run:hover { background: var(--color-teal-dark); box-shadow: var(--shadow-md); }
.btn-run:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-run.loading::after {
  content: '';
  width: 14px; height: 14px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

.timing-hint {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-gray-400);
}

@keyframes spin { to { transform: rotate(360deg); } }

/* ============================================================
   Results Section
   ============================================================ */
.results { margin-bottom: 4rem; display: none; }

.results.visible { display: block; }

.results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.results-header h2 {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  color: var(--color-gray-800);
}

.results-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-gray-400);
}

.chart-container {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  min-height: 400px;
}

.table-container {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.table-scroll {
  overflow-x: auto;
}

.results-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.results-table thead {
  background: var(--color-gray-50);
  border-bottom: 1px solid var(--color-gray-200);
}

.results-table th {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--color-gray-500);
  text-align: left;
  padding: 0.625rem 1rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  white-space: nowrap;
}

.results-table td {
  padding: 0.5rem 1rem;
  border-bottom: 1px solid var(--color-gray-100);
  color: var(--color-gray-700);
  white-space: nowrap;
}

.results-table tbody tr:hover { background: var(--color-gray-50); }

.results-table .num { text-align: right; font-family: var(--font-mono); font-size: 0.8125rem; }

/* ============================================================
   Metrics Grid (for Q01-style metric displays)
   ============================================================ */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.metric-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  text-align: center;
}

.metric-card .metric-value {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-teal);
  margin-bottom: 0.25rem;
}

.metric-card .metric-label {
  font-size: 0.8125rem;
  color: var(--color-gray-500);
}

/* ============================================================
   Footer
   ============================================================ */
footer {
  border-top: 1px solid var(--color-gray-200);
  padding: 32px 48px;
  text-align: center;
}

footer .footer-inner {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.75em;
  color: var(--color-gray-400);
}

footer a { color: var(--color-teal-dark); text-decoration: none; }
footer a:hover { text-decoration: underline; }

/* ============================================================
   Series Headers
   ============================================================ */
.series-header {
  grid-column: 1 / -1;
  padding: 1.5rem 0 0.75rem 0;
  border-bottom: 2px solid var(--color-teal);
  margin-bottom: 0.25rem;
}

.series-header:first-child { padding-top: 0; }

.series-title {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--color-gray-900);
  margin-bottom: 0.25rem;
}

.series-description {
  font-size: 0.85rem;
  color: var(--color-gray-400);
  line-height: 1.5;
  max-width: 60ch;
}

.series-subject {
  display: inline-block;
  margin-top: 0.375rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-teal);
  background: rgba(20,184,166,0.08);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}

/* ============================================================
   Empty State & Loading
   ============================================================ */
.empty-state {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--color-gray-400);
  grid-column: 1 / -1;
}

.empty-state h3 {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--color-gray-500);
}

.loading-overlay {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem;
}

.spinner {
  width: 32px; height: 32px;
  border: 3px solid var(--color-gray-200);
  border-top-color: var(--color-teal);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

/* ============================================================
   Error/Alert
   ============================================================ */
.alert {
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  margin-bottom: 1rem;
}

.alert-error {
  background: rgba(230,57,70,0.1);
  color: var(--color-performance);
  border: 1px solid rgba(230,57,70,0.2);
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 768px) {
  .hero { padding: 48px 24px 56px; }
  .hero h1 { font-size: 2em; }
  .hero .meta-row { flex-direction: column; gap: 8px; }
  .container { padding: 0 24px; }
  .query-grid { grid-template-columns: 1fr; }
  .query-card { padding: 24px; }
  .workspace { grid-template-columns: 1fr; }
  .query-nav { padding: 0.75rem 1rem; }
  .query-header h1 { font-size: 1.5rem; }
  footer .footer-inner { flex-direction: column; gap: 8px; }
}

@media (max-width: 480px) {
  .hero { padding: 36px 16px 40px; }
  .hero h1 { font-size: 1.75em; }
  .container { padding: 0 16px; }
  .query-grid { grid-template-columns: 1fr; gap: 12px; }
  .query-card { padding: 20px; }
  .filters { padding: 1rem 0; }
  footer { flex-direction: column; }
}