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

:root {
  --bg: #0d1117;
  --surface: #161b22;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent: #58a6ff;
  --accent-dim: #1f6feb33;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

header {
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 1rem;
}

header h1 {
  font-size: 1.25rem;
  font-weight: 600;
}

header .tz-badge {
  margin-left: auto;
  font-size: 0.8rem;
  color: var(--text-muted);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.25rem 0.6rem;
}

main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1.5rem 2rem 3rem;
}

/* Drop zone */
#drop-zone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 3rem 2rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
  margin-bottom: 1.5rem;
}

#drop-zone.dragover {
  border-color: var(--accent);
  background: var(--accent-dim);
}

#drop-zone p {
  color: var(--text-muted);
  font-size: 1rem;
}

#drop-zone p strong {
  color: var(--accent);
}

#file-input { display: none; }

/* Controls bar */
#controls {
  display: none;
  gap: 1rem;
  align-items: center;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

#controls.visible { display: flex; }

#controls label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

#controls select {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.35rem 0.6rem;
  font-size: 0.85rem;
  cursor: pointer;
}

#controls .file-info {
  margin-left: auto;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Dashboard grid */
#dashboard {
  display: none;
  flex-direction: column;
  gap: 1.5rem;
}

#dashboard.visible { display: flex; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
}

.card h2 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.card-header h2 {
  margin-bottom: 0;
}

.heatmap-toggle {
  display: flex;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.heatmap-toggle button {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 0.78rem;
  font-weight: 500;
  padding: 0.3rem 0.75rem;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  font-family: inherit;
}

.heatmap-toggle button:not(:last-child) {
  border-right: 1px solid var(--border);
}

.heatmap-toggle button:hover {
  color: var(--text);
}

.heatmap-toggle button.active {
  background: var(--accent);
  color: #fff;
}

.card canvas {
  width: 100% !important;
  margin: 0 auto;
  display: block;
}

#heatmap-container {
  overflow-x: auto;
  text-align: center;
}

#heatmap-container svg {
  display: inline-block;
}

.pie-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.pie-row .card canvas {
  max-width: 400px;
}

@media (max-width: 768px) {
  .pie-row { grid-template-columns: 1fr; }
  main { padding: 1rem; }
}

/* D3 heatmap tooltip */
.heatmap-tooltip {
  position: fixed;
  pointer-events: none;
  background: #1c2128;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.5rem 0.75rem;
  font-size: 0.8rem;
  color: var(--text);
  z-index: 100;
  opacity: 0;
  transition: opacity 0.15s;
  white-space: nowrap;
}

.heatmap-tooltip.visible { opacity: 1; }

/* Summary stats */
.summary-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}

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

.stat-card .value {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-card .label {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}