:root {
  color-scheme: dark;
  --bg: #0e1210;
  --bg-alt: #121712;
  --card: #1a1f1c;
  --border: rgba(255, 255, 255, 0.08);
  --text: #eef1ee;
  --text-muted: #9aa39c;
  --accent: #e8a23d;
  --accent-dim: rgba(232, 162, 61, 0.15);
  --teal: #4fa89b;
  --teal-dim: rgba(79, 168, 155, 0.15);
  --input-bg: #0b0e0c;
  --error: #e07a5f;
  --selection-bg: rgba(232, 162, 61, 0.35);
  --header-bg: rgba(14, 18, 16, 0.85);
  --tok-iri: #7fb3d5;
  --tok-string: #8fbc8f;
  --tok-number: #c9a0dc;

  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2rem;
  --space-6: 3rem;
  --space-8: 5rem;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "Source Code Pro", Menlo, Consolas, monospace;
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f7f5f1;
  --bg-alt: #efece5;
  --card: #ffffff;
  --border: rgba(0, 0, 0, 0.1);
  --text: #1c211e;
  --text-muted: #5b625c;
  --accent: #a37a00;
  --accent-dim: rgba(163, 122, 0, 0.12);
  --teal: #2f7d71;
  --teal-dim: rgba(47, 125, 113, 0.12);
  --input-bg: #ffffff;
  --error: #c14e33;
  --selection-bg: rgba(163, 122, 0, 0.25);
  --header-bg: rgba(247, 245, 241, 0.85);
  --tok-iri: #1a5fb4;
  --tok-string: #1a7a4c;
  --tok-number: #7c3aed;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.7;
  font-size: 1.0625rem;
}

img { max-width: 100%; display: block; }

.container {
  max-width: 1120px;
  margin-inline: auto;
  padding-inline: 1.5rem;
}

.narrow { max-width: 760px; }

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

h1, h2, h3 { line-height: 1.25; font-weight: 650; }

h1 { font-size: clamp(2.25rem, 5vw, 3.75rem); margin: 0 0 var(--space-3); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.1rem); margin: 0 0 var(--space-3); }
h3 { font-size: 1.2rem; margin: 0; }

code, pre { font-family: var(--font-mono); }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-2);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text);
  font-weight: 650;
  text-decoration: none;
  font-size: 1rem;
}

.site-nav {
  display: flex;
  gap: var(--space-4);
}

.site-nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
}

.site-nav a:hover { color: var(--accent); }

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

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
  cursor: pointer;
  flex-shrink: 0;
}

.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.theme-toggle .icon-moon { display: none; }

[data-theme="light"] .theme-toggle .icon-sun { display: none; }
[data-theme="light"] .theme-toggle .icon-moon { display: inline-block; }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--text);
  border-radius: 1px;
}

/* Hero */
.hero {
  padding-block: clamp(4rem, 10vw, 7rem) clamp(3rem, 8vw, 5rem);
}

.hero-sub {
  max-width: 640px;
  color: var(--text-muted);
  font-size: 1.1rem;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.btn {
  display: inline-block;
  padding: 0.7rem 1.3rem;
  border-radius: 6px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--border);
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent);
  color: #14110a;
  border-color: var(--accent);
}

.btn-primary:hover { opacity: 0.9; }

.btn-secondary {
  background: transparent;
  color: var(--text);
}

.btn-secondary:hover { border-color: var(--accent); color: var(--accent); }

.btn-tiny {
  padding: 0.4rem 0.8rem;
  font-size: 0.82rem;
}

/* Stats */
.stats {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--bg-alt);
  padding-block: var(--space-6);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-4);
  text-align: center;
}

.stat-num {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.stat-label {
  color: var(--text-muted);
  font-size: 0.85rem;
  letter-spacing: 0.03em;
  margin-top: 0.25rem;
}

/* Sections */
.section {
  padding-block: clamp(3rem, 8vw, 6rem);
}

.section.alt { background: var(--bg-alt); }

.section-intro {
  color: var(--text-muted);
  margin-top: -0.5rem;
}

.checklist {
  padding-left: 1.2rem;
  color: var(--text-muted);
}

.checklist li { margin-bottom: 0.4rem; }

/* Diagram */
.diagram-figure {
  margin: var(--space-4) 0;
}

.diagram-figure a {
  display: block;
  background: #fff;
  border-radius: 10px;
  padding: var(--space-2);
  border: 1px solid var(--border);
}

.diagram-figure figcaption {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 0.6rem;
}

.pipeline-steps {
  padding-left: 1.2rem;
}

.pipeline-steps li { margin-bottom: 0.5rem; }

.ml-callout {
  margin-top: var(--space-4);
  padding: var(--space-3);
  background: var(--card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 6px;
}

/* Code blocks */
.code-block {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: var(--space-3);
  overflow-x: auto;
  font-size: 0.85rem;
  color: var(--text);
}

.code-block-wrap {
  position: relative;
}

.code-block-wrap .copy-btn {
  position: absolute;
  top: var(--space-2);
  right: var(--space-2);
}

/* Chip grid */
.chip-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: var(--space-3) 0 var(--space-4);
}

.chip {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.4rem 0.9rem;
  font-size: 0.85rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
}

.download-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

/* Explore / iframe cards */
.explore-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  margin-top: var(--space-4);
}

.tool-card {
  flex: 1 1 420px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: var(--space-3);
}

.tool-card-teal { border-color: var(--teal-dim); }
.tool-card-teal h3 { color: var(--teal); }

.tool-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-bottom: 0.5rem;
}

.tool-card p { color: var(--text-muted); margin-top: 0; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

.example-queries {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: var(--space-2);
}

.example-queries-label {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.chip-btn {
  font-family: var(--font-sans);
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}

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

.code-editor {
  position: relative;
}

.code-editor-highlight,
.sparql-input {
  margin: 0;
  width: 100%;
  min-height: 180px;
  box-sizing: border-box;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: var(--space-2);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.5;
  white-space: pre-wrap;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.code-editor-highlight {
  position: absolute;
  inset: 0;
  overflow: auto;
  pointer-events: none;
  background: var(--input-bg);
  color: var(--text);
}

.sparql-input {
  position: relative;
  background: transparent;
  color: transparent;
  caret-color: var(--text);
  resize: vertical;
}

.sparql-input::selection {
  background: var(--selection-bg);
}

.sparql-input:focus {
  outline: none;
  border-color: var(--accent);
}

.tok-keyword { color: var(--accent); font-weight: 600; }
.tok-variable { color: var(--teal); }
.tok-iri { color: var(--tok-iri); }
.tok-string { color: var(--tok-string); }
.tok-number { color: var(--tok-number); }
.tok-comment { color: var(--text-muted); font-style: italic; }

.sparql-lint {
  font-size: 0.8rem;
  margin-top: 0.4rem;
  min-height: 1.1em;
  font-family: var(--font-mono);
}

.sparql-lint.valid {
  color: var(--teal);
}

.sparql-lint.invalid {
  color: var(--error);
}

.sparql-controls {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin: var(--space-2) 0;
}

.sparql-status {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.sparql-results {
  margin-top: var(--space-2);
}

.sparql-error {
  color: var(--error);
  font-size: 0.9rem;
}

.sparql-empty {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.results-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
  max-height: 420px;
  overflow-y: auto;
}

.results-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
}

.results-table th,
.results-table td {
  text-align: left;
  padding: 0.5rem 0.7rem;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

.results-table th {
  background: var(--bg-alt);
  color: var(--text-muted);
  position: sticky;
  top: 0;
}

.results-table a {
  color: var(--accent);
}

.iframe-wrap {
  position: relative;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  height: 640px;
  background: #fff;
}

.tool-iframe {
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}

.iframe-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  background: var(--card);
  color: var(--text-muted);
  font-size: 0.9rem;
  text-align: center;
  padding: var(--space-2);
}

.spinner {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  animation: spin 0.9s linear infinite;
}

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

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding-block: var(--space-6);
  background: var(--bg-alt);
}

.footer-inner { text-align: center; }

.footer-links {
  display: flex;
  justify-content: center;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-bottom: var(--space-2);
}

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

.footer-note, .footer-affiliation {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin: 0.25rem 0;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-toggle { display: flex; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: var(--space-2) var(--space-3);
    display: none;
    gap: var(--space-2);
  }

  .site-nav.open { display: flex; }

  .iframe-wrap { height: 480px; }

  .stats-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr; }
}

/* Full-screen query page (query.html) */
.query-page-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.query-page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--border);
}

.query-page-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  max-width: 1400px;
  width: 100%;
  margin-inline: auto;
  padding: var(--space-3);
}

.query-page-main h1 {
  margin-bottom: 0.25rem;
}

.query-page-input {
  min-height: 280px;
}

.query-page-results {
  flex: 1;
}

.query-page-results .results-table-wrap {
  max-height: none;
}

@media (min-width: 769px) {
  .query-page-results .results-table-wrap {
    max-height: calc(100vh - 480px);
  }
}