:root {
  --bg: #0e1117;
  --panel: #151b26;
  --panel-2: #1b2331;
  --line: #263143;
  --text: #d7e0ee;
  --muted: #8394ad;
  --accent: #5b8cff;
  --accent-2: #7c5bff;
}
* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body {
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

#topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 16px;
  background: linear-gradient(180deg, #131a26, #0f141d);
  border-bottom: 1px solid var(--line);
}
.brand { font-weight: 700; letter-spacing: .3px; display: flex; align-items: center; gap: 8px; }
.brand i { color: var(--accent); }
.brand .tag {
  font-size: 11px; font-weight: 500; color: var(--muted);
  background: var(--panel-2); padding: 2px 8px; border-radius: 20px; margin-left: 6px;
}
.toolbar { display: flex; align-items: center; gap: 6px; }
.tool {
  background: var(--panel-2); color: var(--text); border: 1px solid var(--line);
  padding: 8px 11px; border-radius: 8px; cursor: pointer; font-size: 13px;
  transition: all .15s ease;
}
.tool:hover { border-color: var(--accent); }
.tool.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.tool.primary { background: linear-gradient(90deg, var(--accent), var(--accent-2)); border: none; font-weight: 600; }
.divider { width: 1px; height: 22px; background: var(--line); margin: 0 4px; }

#stage { flex: 1; display: flex; min-height: 0; }
#viewport { flex: 1; position: relative; min-width: 0; }
#viewport canvas { display: block; }

#panel-wrap {
  width: 320px; background: var(--panel); border-left: 1px solid var(--line);
  overflow-y: auto; display: flex; flex-direction: column;
}
#panel { padding: 16px; }

/* Object list (tire / rim) */
#objects { padding: 14px 16px 6px; border-bottom: 1px solid var(--line); }
#objects h3 {
  font-size: 11px; text-transform: uppercase; letter-spacing: 1px;
  color: var(--muted); margin: 0 0 10px;
}
.obj-row {
  display: flex; align-items: center; justify-content: space-between;
  padding: 8px 10px; border-radius: 8px; cursor: pointer;
  border: 1px solid transparent; margin-bottom: 4px; font-size: 13px;
}
.obj-row:hover { background: var(--panel-2); }
.obj-row.selected { background: rgba(91,140,255,.14); border-color: var(--accent); }
.obj-name { display: flex; align-items: center; gap: 8px; }
.obj-name i { color: var(--muted); }
.obj-row.selected .obj-name i { color: var(--accent); }
.obj-del {
  background: transparent; border: none; color: var(--muted);
  cursor: pointer; padding: 4px 6px; border-radius: 6px;
}
.obj-del:hover { color: #ff6b6b; background: rgba(255,107,107,.1); }

/* Draw controls overlay */
#draw-controls {
  display: none; position: absolute; top: 16px; left: 16px; z-index: 10;
  flex-direction: column; gap: 10px; width: 260px;
  background: rgba(21,27,38,.92); backdrop-filter: blur(8px);
  border: 1px solid var(--accent); border-radius: 12px; padding: 14px 16px;
  box-shadow: 0 10px 40px rgba(0,0,0,.5);
}
.dc-title { font-weight: 700; font-size: 14px; display: flex; align-items: center; gap: 8px; }
.dc-title i { color: var(--accent); }
.dc-toggle { display: flex; align-items: center; gap: 8px; font-size: 13px; cursor: pointer; }
.dc-toggle input { accent-color: var(--accent); width: 15px; height: 15px; }
.dc-row { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--muted); }
.dc-row input[type="range"] { flex: 1; accent-color: var(--accent); }
.dc-val { color: var(--accent); font-variant-numeric: tabular-nums; min-width: 16px; text-align: right; }
.dc-guess {
  font-size: 12px; color: var(--text); min-height: 16px; line-height: 1.45;
  border-left: 2px solid var(--accent-2); padding-left: 8px;
}
.dc-actions { display: flex; gap: 8px; margin-top: 2px; }
.dc-actions .tool { flex: 1; text-align: center; }
.panel-header { margin-bottom: 8px; }
.panel-header h2 { margin: 6px 0 0; font-size: 20px; }
.type-badge {
  font-size: 10px; text-transform: uppercase; letter-spacing: 1px;
  color: var(--accent); background: rgba(91,140,255,.12);
  padding: 3px 8px; border-radius: 5px;
}
.param-group { margin-top: 18px; }
.param-group h3 {
  font-size: 11px; text-transform: uppercase; letter-spacing: 1px;
  color: var(--muted); margin: 0 0 10px; padding-bottom: 6px;
  border-bottom: 1px solid var(--line);
}
.param-row { margin-bottom: 14px; }
.param-row label {
  display: flex; justify-content: space-between; align-items: baseline;
  font-size: 13px; margin-bottom: 6px;
}
.param-value { color: var(--accent); font-variant-numeric: tabular-nums; font-size: 12px; }
.param-row input[type="range"] { width: 100%; accent-color: var(--accent); }
.param-row select {
  width: 100%; background: var(--panel-2); color: var(--text);
  border: 1px solid var(--line); border-radius: 7px; padding: 7px 9px; font-size: 13px;
}

#hint {
  padding: 8px 16px; font-size: 12px; color: var(--muted);
  background: #0f141d; border-top: 1px solid var(--line); text-align: center;
}
#hint em { color: var(--text); font-style: normal; font-weight: 600; }

/* ===== Empty state (blank canvas prompt) ===== */
#empty-state {
  position: absolute; inset: 0; z-index: 6;
  display: flex; align-items: center; justify-content: center;
  pointer-events: none;
}
.empty-card {
  pointer-events: auto; text-align: center; max-width: 380px;
  padding: 32px 34px; border-radius: 16px;
  background: rgba(21,27,38,.72); backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  box-shadow: 0 20px 60px rgba(0,0,0,.5);
}
.empty-icon {
  width: 58px; height: 58px; margin: 0 auto 16px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; font-size: 22px;
  color: #fff; background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 8px 24px rgba(91,140,255,.4);
}
.empty-card h2 { margin: 0 0 8px; font-size: 22px; }
.empty-card p { margin: 0 0 18px; font-size: 13px; line-height: 1.55; color: var(--muted); }

/* ===== Promotion prompt ("I think this is a Wheel 98%") ===== */
#promote {
  display: none; position: absolute; top: 16px; left: 50%; transform: translateX(-50%);
  z-index: 12; justify-content: center;
}
.promote-card {
  min-width: 300px; padding: 16px 18px; border-radius: 14px;
  background: rgba(21,27,38,.94); backdrop-filter: blur(10px);
  border: 1px solid var(--accent);
  box-shadow: 0 16px 50px rgba(0,0,0,.55);
  animation: promote-in .22s ease;
}
@keyframes promote-in {
  from { opacity: 0; transform: translateY(-8px); }
  to   { opacity: 1; transform: translateY(0); }
}
.promote-title {
  font-size: 11px; text-transform: uppercase; letter-spacing: 1px; color: var(--muted);
}
.promote-guess { display: flex; align-items: baseline; gap: 10px; margin: 6px 0 4px; }
.promote-label { font-size: 22px; font-weight: 700; }
.promote-conf {
  font-size: 13px; font-weight: 700; font-variant-numeric: tabular-nums;
  padding: 2px 9px; border-radius: 20px;
}
.promote-conf.ok  { color: #7ee0a6; background: rgba(126,224,166,.14); }
.promote-conf.low { color: #ffcc66; background: rgba(255,204,102,.14); }
.promote-sub { font-size: 12px; color: var(--muted); margin-bottom: 12px; line-height: 1.45; }
.promote-actions { display: flex; gap: 8px; }
.promote-actions .tool { flex: 1; text-align: center; }

/* ===== Panel empty message ===== */
.panel-empty { font-size: 13px; color: var(--muted); padding: 8px 2px; line-height: 1.5; }

/* ===== Derived (auto-computed) params ===== */
.derived-group h3 { display: flex; align-items: center; gap: 8px; }
.derived-tag {
  font-size: 9px; text-transform: uppercase; letter-spacing: 1px; color: var(--accent-2);
  background: rgba(124,91,255,.14); padding: 2px 7px; border-radius: 20px;
  border: none;
}
.derived-row { margin-bottom: 9px; }
.derived-row label { margin-bottom: 0; color: var(--muted); }
.derived-value { color: var(--text) !important; font-weight: 600; }

/* ===== "affects" relationship chips (every driver knows what it affects) ===== */
.affects {
  margin-top: 7px; font-size: 10.5px; color: var(--muted);
  display: flex; flex-wrap: wrap; align-items: center; gap: 5px; line-height: 1.4;
}
.affects i { color: var(--accent-2); font-size: 10px; }
.affects span {
  color: var(--accent); background: rgba(91,140,255,.1);
  padding: 1px 7px; border-radius: 20px; font-variant-numeric: tabular-nums;
}