:root {
  --bg: #f4f4f6;
  --panel: #ffffff;
  --ink: #1c1c1f;
  --muted: #6b6b72;
  --faint: #b6b6bd;
  --line: #e2e2e7;
  --accent: #2846a0;
  --canvas-bg: #202225;
  --font: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 14px;
}

.app {
  display: grid;
  grid-template-columns: 290px 1fr;
  gap: 14px;
  height: 100vh;
  padding: 12px;
}

/* ---- controls ---- */
.controls {
  overflow-y: auto;
  padding: 4px 12px 16px 4px;
}

.title h1 { margin: 0; font-size: 18px; font-weight: 700; }
.title .subtitle { margin: 2px 0 12px; color: var(--muted); }

.row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin: 6px 0;
}

.row > span { color: var(--ink); }
.row select { width: 60%; }

select, button {
  font-family: inherit;
  font-size: 13px;
  padding: 4px 6px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: var(--panel);
  color: var(--ink);
}

.slider { margin: 8px 0; }
.slider-head {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
}
.slider-name { color: var(--ink); }
.slider-val { color: var(--muted); }
.slider input[type="range"] { width: 100%; margin-top: 4px; accent-color: var(--accent); }

.slider.disabled { opacity: 0.4; }
.row.disabled { opacity: 0.4; }

.hint { color: var(--muted); font-size: 12px; margin: 2px 0 6px; }
.hint.off { color: var(--faint); }

.swatch-row input[type="color"] {
  width: 48px;
  height: 26px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: none;
  cursor: pointer;
}

.check-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 6px 0;
  cursor: pointer;
}
.check-row input { accent-color: var(--accent); }

hr { border: none; border-top: 1px solid var(--line); margin: 14px 0; }

.actions {
  display: flex;
  gap: 8px;
  align-items: stretch;
}
.actions > button { flex: 1; }
.save-group { display: flex; flex: 1.4; gap: 6px; }
.save-group select { flex: 0 0 auto; }
.save-group button { flex: 1; }

button {
  cursor: pointer;
  font-weight: 600;
}
button:hover { border-color: var(--accent); }
button:active { background: #f0f0f4; }

/* ---- preview ---- */
.preview-pane {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.canvas-wrap {
  flex: 1;
  min-height: 0;
  background: var(--canvas-bg);
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
}

#preview { display: block; width: 100%; height: 100%; cursor: crosshair; }

.status {
  margin: 8px 2px 0;
  color: var(--muted);
  font-size: 13px;
  min-height: 18px;
}