:root {
  --bg: #0e1116;
  --panel: #161b22;
  --panel2: #1f2630;
  --text: #e6edf3;
  --muted: #8b949e;
  --accent: #58a6ff;
  --border: #30363d;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, sans-serif;
  font-size: 14px;
  line-height: 1.5;
}

header {
  padding: 24px 32px 8px;
  border-bottom: 1px solid var(--border);
}

header h1 {
  margin: 0;
  font-size: 28px;
  letter-spacing: -0.5px;
}

.tag {
  margin: 4px 0 0;
  color: var(--muted);
}

main {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 24px;
  padding: 24px 32px;
  align-items: start;
}

@media (max-width: 900px) {
  main { grid-template-columns: 1fr; }
}

.controls {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
}

@media (min-width: 901px) {
  .controls {
    position: sticky;
    top: 16px;
    max-height: calc(100vh - 32px);
    overflow-y: auto;
  }
}

.controls h2,
.viz h2,
.panel h2 {
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin: 0 0 12px;
  color: var(--muted);
}

.field {
  margin-bottom: 14px;
}

.field label {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  margin-bottom: 4px;
}

.hint {
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

select, input[type="number"], input[type="color"] {
  background: var(--panel2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 6px 8px;
  font-size: 13px;
  width: 100%;
}

input[type="color"] {
  height: 28px;
  padding: 2px;
  width: 44px;
}

.presets {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 8px;
}

.presets button {
  background: var(--panel2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 4px 8px;
  font-size: 12px;
  cursor: pointer;
}

.presets button:hover { border-color: var(--accent); }

#groupsEditor {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 6px;
  max-height: 280px;
  overflow-y: auto;
  padding-right: 4px;
}

.group-row {
  display: grid;
  grid-template-columns: 36px 1fr 36px 24px;
  gap: 6px;
  align-items: center;
}

.group-row input[type="color"] {
  width: 36px;
  height: 24px;
}

.group-row .pct {
  font-size: 11px;
  color: var(--muted);
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.group-row button {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 4px;
  cursor: pointer;
  font-size: 12px;
  height: 24px;
  padding: 0;
}

.group-row button:hover { color: var(--text); border-color: var(--accent); }

button.small {
  background: transparent;
  color: var(--accent);
  border: 1px dashed var(--border);
  border-radius: 4px;
  padding: 4px 8px;
  font-size: 12px;
  cursor: pointer;
}

.actions {
  display: flex;
  gap: 6px;
  margin-top: 16px;
}

.actions button {
  flex: 1;
  background: var(--accent);
  color: #0d1117;
  border: 0;
  border-radius: 4px;
  padding: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}

.actions button.secondary {
  background: var(--panel2);
  color: var(--text);
  border: 1px solid var(--border);
  font-weight: 400;
}

.actions button:hover { filter: brightness(1.1); }
.actions button:disabled { opacity: 0.5; cursor: not-allowed; }

.viz {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
}

.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.panel-head h2 { margin: 0; }

.avg-swatch {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: #000;
}

canvas {
  display: block;
  width: 100%;
  height: auto;
  background: var(--panel2);
  border-radius: 4px;
}

#avgChart, #divChart { aspect-ratio: 3 / 1; }
#popCanvas { aspect-ratio: 1 / 1; }

.stats table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

.stats td {
  padding: 6px 0;
  border-bottom: 1px solid var(--border);
}

.stats td:first-child { color: var(--muted); }
.stats td:last-child { text-align: right; font-variant-numeric: tabular-nums; }

footer {
  padding: 16px 32px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 12px;
}

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