:root {
  --bg: #0f1117;
  --surface: #1a1d27;
  --surface2: #242736;
  --border: #2e3248;
  --accent: #5c6bc0;
  --accent-hover: #7986cb;
  --text: #e2e4ef;
  --text-muted: #7b7f9e;
  --success: #4caf50;
  --error: #ef5350;
  --warning: #ff9800;
  --font: 'Inter', system-ui, -apple-system, sans-serif;
  --mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
}

/* ── Light mode ───────────────────────────────────────── */
html[data-theme="light"],
[data-theme="light"] {
  --bg: #f4f5f9;
  --surface: #ffffff;
  --surface2: #eef0f6;
  --border: #d1d5e8;
  --accent: #5c6bc0;
  --accent-hover: #3949ab;
  --text: #1a1d2e;
  --text-muted: #6b7299;
  --success: #2e7d32;
  --error: #c62828;
  --warning: #e65100;
}
html[data-theme="light"] #graph-container { background: #f0f2fa; }
html[data-theme="light"] .sparql-block { color: #2d6a2d; }
html[data-theme="light"] ::-webkit-scrollbar-track { background: var(--surface2); }

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 14px;
  line-height: 1.6;
  min-height: 100vh;
}

/* ── Top bar ─────────────────────────────────────────── */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  display: flex;
  align-items: center;
  height: 56px;
  gap: 16px;
  position: sticky;
  top: 0;
  z-index: 100;
}
header h1 {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text);
  white-space: nowrap;
}
header .badge {
  background: var(--accent);
  color: #fff;
  font-size: 10px;
  padding: 2px 7px;
  border-radius: 999px;
  font-weight: 600;
  letter-spacing: 0.04em;
}
.header-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 10px;
}
.stat-chip {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 4px 12px;
  font-size: 12px;
  color: var(--text-muted);
}
.stat-chip strong { color: var(--text); }

/* ── Nav tabs ─────────────────────────────────────────── */
nav {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  display: flex;
  gap: 4px;
}
nav button {
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  padding: 12px 16px;
  transition: color 0.15s, border-color 0.15s;
}
nav button:hover { color: var(--text); }
nav button.active { color: var(--accent-hover); border-bottom-color: var(--accent-hover); }

/* ── Layout ───────────────────────────────────────────── */
main { max-width: 1200px; margin: 0 auto; padding: 24px; }

.tab-panel { display: none; }
.tab-panel.active { display: block; }

.panel-header {
  margin-bottom: 20px;
}
.panel-header h2 { font-size: 18px; font-weight: 600; margin-bottom: 4px; }
.panel-header p  { color: var(--text-muted); font-size: 13px; }

/* ── Cards ────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 16px;
}
.card-title {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 14px;
}

/* ── Buttons ──────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--accent);
  border: none;
  border-radius: 8px;
  color: #fff;
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  padding: 8px 16px;
  transition: background 0.15s, opacity 0.15s;
}
.btn:hover { background: var(--accent-hover); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-sm { padding: 5px 10px; font-size: 12px; border-radius: 6px; }
.btn-outline {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
}
.btn-outline:hover { background: var(--surface2); }
.btn-danger { background: var(--error); }
.btn-success { background: var(--success); }

/* ── Form controls ────────────────────────────────────── */
select, input, textarea {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: var(--font);
  font-size: 13px;
  padding: 8px 12px;
  width: 100%;
  transition: border-color 0.15s;
}
select:focus, input:focus, textarea:focus {
  outline: none;
  border-color: var(--accent);
}
select { cursor: pointer; }
label { display: block; font-size: 12px; color: var(--text-muted); margin-bottom: 5px; }

textarea.mono { font-family: var(--mono); font-size: 12px; resize: vertical; }

/* ── Tables ───────────────────────────────────────────── */
.table-wrap {
  overflow-x: auto;
  border-radius: 8px;
  border: 1px solid var(--border);
}
table { width: 100%; border-collapse: collapse; }
thead th {
  background: var(--surface2);
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  padding: 10px 14px;
  text-align: left;
  text-transform: uppercase;
  white-space: nowrap;
}
tbody tr { border-top: 1px solid var(--border); }
tbody tr:hover { background: var(--surface2); cursor: pointer; }
tbody td { padding: 10px 14px; font-size: 13px; max-width: 280px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
tbody td.wrap { white-space: normal; word-break: break-all; }

/* ── Sub-tabs (for Query panel) ───────────────────────── */
.subtabs {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
  background: var(--surface2);
  border-radius: 8px;
  padding: 4px;
  width: fit-content;
}
.subtabs button {
  background: none;
  border: none;
  border-radius: 6px;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 12px;
  font-weight: 500;
  padding: 6px 14px;
  transition: all 0.15s;
}
.subtabs button.active { background: var(--accent); color: #fff; }
.subtabs button:hover:not(.active) { color: var(--text); }

/* ── SPARQL display ───────────────────────────────────── */
.sparql-block {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
  font-family: var(--mono);
  font-size: 12px;
  white-space: pre-wrap;
  word-break: break-all;
  color: #a8d8a8;
  max-height: 300px;
  overflow-y: auto;
}

details summary {
  cursor: pointer;
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 8px;
  user-select: none;
}
details summary:hover { color: var(--text); }

/* ── Guided query builder ─────────────────────────────── */
.filter-row {
  display: grid;
  grid-template-columns: 1fr 100px 160px 32px;
  gap: 8px;
  align-items: end;
  margin-bottom: 8px;
}
.filter-row .remove-btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 16px;
  height: 34px;
  width: 32px;
  transition: color 0.15s, border-color 0.15s;
}
.filter-row .remove-btn:hover { color: var(--error); border-color: var(--error); }

/* ── Alerts ───────────────────────────────────────────── */
.alert {
  border-radius: 8px;
  font-size: 13px;
  margin-bottom: 12px;
  padding: 10px 14px;
}
.alert-error   { background: rgba(239,83,80,0.12); border: 1px solid rgba(239,83,80,0.4); color: #ef5350; }
.alert-success { background: rgba(76,175,80,0.12); border: 1px solid rgba(76,175,80,0.4); color: #4caf50; }
.alert-info    { background: rgba(92,107,192,0.12); border: 1px solid rgba(92,107,192,0.4); color: var(--accent-hover); }

/* ── Spinner ──────────────────────────────────────────── */
.spinner {
  display: inline-block;
  width: 14px; height: 14px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Detail side panel ────────────────────────────────── */
.detail-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  margin-top: 16px;
  display: none;
}
.detail-panel.open { display: block; }
.detail-panel h3 { font-size: 15px; font-weight: 600; margin-bottom: 14px; }
.detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.detail-item { background: var(--surface2); border-radius: 8px; padding: 10px 14px; }
.detail-item .key { font-size: 11px; color: var(--text-muted); margin-bottom: 3px; text-transform: uppercase; letter-spacing: 0.06em; }
.detail-item .val { font-size: 13px; word-break: break-all; }

/* ── Export buttons ───────────────────────────────────── */
.export-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}
.export-card {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}
.export-card:hover { border-color: var(--accent); background: rgba(92,107,192,0.08); }
.export-card .icon { font-size: 32px; margin-bottom: 10px; }
.export-card .fmt  { font-weight: 600; font-size: 15px; margin-bottom: 4px; }
.export-card .desc { font-size: 12px; color: var(--text-muted); }

/* ── Empty state ──────────────────────────────────────── */
.empty { text-align: center; padding: 48px 0; color: var(--text-muted); }
.empty .icon { font-size: 40px; margin-bottom: 10px; }
.empty p { font-size: 13px; }

/* ── Scrollbar ────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--surface); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ── Graph visualisation ──────────────────────────────── */
#graph-container {
  width: 100%;
  height: 520px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  margin-bottom: 16px;
  position: relative;
}

.graph-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}
.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  color: var(--text-muted);
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px 9px;
}
.legend-item::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--legend-color, var(--text-muted));
}
.legend-item[data-group="sample"]      { --legend-color: #5c6bc0; }
.legend-item[data-group="structure"]   { --legend-color: #29b6f6; }
.legend-item[data-group="element"]     { --legend-color: #4caf50; }
.legend-item[data-group="material"]    { --legend-color: #ef5350; }
.legend-item[data-group="calculation"] { --legend-color: #ab47bc; }
.legend-item[data-group="potential"]   { --legend-color: #ff9800; }
.legend-item[data-group="property"]    { --legend-color: #ffca28; }
.legend-item[data-group="other"]       { --legend-color: #546e7a; }

/* ── Responsive ───────────────────────────────────────── */
@media (max-width: 640px) {
  main { padding: 14px; }
  .filter-row { grid-template-columns: 1fr; }
  .export-grid { grid-template-columns: 1fr; }
  .detail-grid { grid-template-columns: 1fr; }
}

/* ── Theme toggle ─────────────────────────────────────── */
.theme-toggle {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 15px;
  height: 32px;
  width: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, color 0.15s;
}
.theme-toggle:hover { background: var(--border); color: var(--text); }

/* ── Notice badge (experimental / info) ──────────────── */
.notice {
  background: rgba(255,152,0,0.1);
  border: 1px solid rgba(255,152,0,0.35);
  border-radius: 8px;
  color: var(--warning);
  font-size: 12px;
  padding: 8px 14px;
  margin-bottom: 14px;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  line-height: 1.5;
}

/* ── Footer ───────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  margin-top: 32px;
  padding: 20px 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  justify-content: center;
  align-items: center;
  font-size: 12px;
  color: var(--text-muted);
}
footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}
footer a:hover { color: var(--accent-hover); text-decoration: underline; }
footer .sep { opacity: 0.3; }

/* ── Workflow cards ───────────────────────────────────── */
.workflow-type-badge {
  display: inline-block;
  background: rgba(92,107,192,0.15);
  border: 1px solid rgba(92,107,192,0.35);
  border-radius: 5px;
  color: var(--accent-hover);
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  white-space: nowrap;
}