:root {
  --bg: #ffffff;
  --panel-bg: #ffffff;
  --accent: #ff6a00;
  --accent-2: #ff8733;
  --ink: #1a1a1a;
  --ink-soft: #4a4a4a;
  --muted: #9a9a9a;
  --line: #e6e6e6;
  --tile-bg: #fafafa;
  --tile-bg-hover: #f0f0f0;
  --selected: #ff6a00;
  --radius: 4px;
  --shadow: 0 1px 2px rgba(0,0,0,0.04);
}

* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  display: flex;
  overflow: hidden;
}

/* ---------- sidebar ---------- */
.sidebar {
  width: 360px;
  flex: 0 0 360px;
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.price-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px;
  border-bottom: 1px solid var(--line);
  background: var(--panel-bg);
  position: sticky; top: 0; z-index: 2;
}
.price-tag {
  display: flex; align-items: center; gap: 8px;
  background: var(--accent);
  color: white;
  padding: 8px 12px;
  border-radius: var(--radius);
  font-weight: 600;
  flex: 1;
}
.discount { font-size: 12px; }
.price-now { font-size: 16px; }
.price-old { font-size: 12px; opacity: 0.8; text-decoration: line-through; }

.add-cart {
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--accent);
  color: white;
  border: 0;
  padding: 10px 14px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 13px;
  cursor: pointer;
}
.add-cart:hover { background: var(--accent-2); }

.panel-title {
  font-size: 14px;
  font-weight: 700;
  margin: 0;
  padding: 12px;
  color: white;
  background: var(--accent);
  letter-spacing: 0.02em;
}

.group { padding: 14px 12px 4px; border-bottom: 1px solid var(--line); }
.group h3 {
  font-size: 13px; font-weight: 700;
  margin: 0 0 10px; color: var(--ink);
}
.group h3 .muted { color: var(--muted); font-weight: 400; font-size: 11px; margin-left: 4px; }

.slider-row {
  display: grid;
  grid-template-columns: 100px 38px 1fr 28px;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  margin: 8px 0 12px;
}
.slider-row .label { color: var(--ink-soft); }
.slider-row output {
  text-align: center; font-size: 11px;
  padding: 2px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.slider-row .max { text-align: right; color: var(--muted); font-size: 11px; }
.slider-row input[type=range] { accent-color: var(--accent); width: 100%; }

/* ---------- dimension sliders ---------- */
.dim-group { padding: 16px 12px; }
.dim-row {
  display: grid;
  grid-template-columns: 110px 1fr;
  align-items: center;
  gap: 16px;
  margin: 14px 0;
}
.dim-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--ink);
  line-height: 1.25;
}
.dim-slider { position: relative; padding-top: 22px; }
.dim-bubble {
  position: absolute;
  top: 0;
  left: 0;
  transform: translateX(-50%);
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 500;
  color: var(--ink);
  background: var(--tile-bg);
  border: 1px solid var(--line);
  border-radius: 3px;
  pointer-events: none;
  white-space: nowrap;
}
.dim-track {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--ink-soft);
}
.dim-track input[type=range] {
  width: 100%;
  accent-color: var(--accent);
  margin: 0;
}

.grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
  margin-bottom: 8px;
}
.grid.small { grid-template-columns: repeat(2, 1fr); gap: 10px; }

.tile {
  border: 2px solid transparent;
  background: var(--tile-bg);
  border-radius: var(--radius);
  padding: 6px 4px 4px;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
  display: flex; flex-direction: column;
  align-items: center; gap: 4px;
}
.tile:hover { background: var(--tile-bg-hover); }
.tile.selected { border-color: var(--selected); background: #fff7f0; }
.tile.disabled { opacity: 0.4; cursor: not-allowed; }

.tile-art {
  width: 100%; aspect-ratio: 1;
  background: linear-gradient(135deg, #e9ded0, #d9cdbb);
  border-radius: 3px;
  display: flex; align-items: center; justify-content: center;
  color: var(--ink-soft);
  font-size: 14px;
}
.tile-label { font-size: 10.5px; color: var(--ink-soft); text-align: center; }

/* Schematic armrest icons (minimal vector previews) */
.tile-art.ar {
  background: #ffffff;
  border: 1px solid var(--line);
  overflow: hidden;
}
.tile-art.ar svg { width: 80%; height: 80%; }
.tile-art .tile-thumb {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

/* ---------- viewport ---------- */
.viewport {
  flex: 1;
  position: relative;
  background: #fafafa;
  overflow: hidden;
}
#canvas { width: 100%; height: 100%; display: block; }

.scene-toolbar {
  position: absolute; top: 12px; right: 16px;
  display: flex; align-items: center; gap: 10px;
  z-index: 5;
}
.scene-toolbar button {
  background: white;
  border: 1px solid var(--line);
  color: var(--ink-soft);
  padding: 6px 10px;
  border-radius: var(--radius);
  font-size: 12px;
  cursor: pointer;
}
.scene-toolbar button:hover { background: var(--tile-bg); }
.status {
  font-size: 11px; color: var(--muted);
  font-variant-numeric: tabular-nums;
}

/* ---------- loading overlay ---------- */
.loading {
  position: absolute; inset: 0;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  background: rgba(255,255,255,0.85);
  z-index: 10;
  color: var(--ink-soft);
  font-size: 13px;
  gap: 10px;
}
.loading .spinner {
  width: 28px; height: 28px;
  border: 3px solid var(--line);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }