:root {
  --bg: #f4f2ee;
  --panel: #ffffff;
  --ink: #23262b;
  --muted: #6b7078;
  --line: #dedad3;
  --accent: #2e6fd8;
  --accent-ink: #ffffff;
  --ok: #2f8f4e;
  --bad: #c7392f;
  --warn: #b7791f;
  --field: #fbfaf8;
  /* Canvas palette */
  --cv-bg: #e9e6e0;
  --cv-apron: #c9c6c0;
  --cv-floor: #f7f5f1;
  --cv-grid: rgba(60, 60, 60, 0.07);
  --cv-grid5: rgba(60, 60, 60, 0.16);
  --cv-wall: #3b3f46;
  --cv-door: #2e6fd8;
  --cv-obstacle: #8a7f72;
  --cv-text: #3b3f46;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17191d;
    --panel: #1f2227;
    --ink: #e6e7ea;
    --muted: #9aa0a8;
    --line: #33373e;
    --accent: #5b93f0;
    --field: #191b1f;
    --cv-bg: #121417;
    --cv-apron: #2a2d32;
    --cv-floor: #1d2025;
    --cv-grid: rgba(255, 255, 255, 0.05);
    --cv-grid5: rgba(255, 255, 255, 0.12);
    --cv-wall: #c9ccd2;
    --cv-door: #5b93f0;
    --cv-obstacle: #7d756b;
    --cv-text: #c9ccd2;
  }
}

* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  font: 14px/1.4 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--ink);
  display: flex;
  flex-direction: column;
}

.topbar {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 16px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}
.topbar h1 { font-size: 18px; margin: 0; }
.tagline { color: var(--muted); }
.spacer { flex: 1; }

.layout { flex: 1; display: flex; min-height: 0; }
.sidebar {
  width: 360px; flex-shrink: 0;
  overflow-y: auto;
  background: var(--panel);
  border-right: 1px solid var(--line);
  padding: 4px 16px 24px;
}
.sidebar section { border-bottom: 1px solid var(--line); padding: 12px 0; }
.sidebar section:last-child { border-bottom: 0; }
.sidebar h2 { font-size: 13px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin: 0 0 8px; }
.hint { color: var(--muted); font-size: 12px; margin: 8px 0 0; }
code, kbd { font-size: 12px; background: var(--field); border: 1px solid var(--line); border-radius: 3px; padding: 0 3px; }

label { display: flex; flex-direction: column; gap: 3px; font-size: 12px; color: var(--muted); }
label.check, label.inline { flex-direction: row; align-items: center; gap: 6px; color: var(--ink); font-size: 13px; }
label.check { margin-top: 8px; }
input, select {
  font: inherit; color: var(--ink);
  background: var(--field);
  border: 1px solid var(--line); border-radius: 5px;
  padding: 5px 7px; min-width: 0;
}
input[type="checkbox"] { padding: 0; }
input[type="range"] { padding: 0; width: 90px; }
input[type="number"] { width: 64px; }
label > input, label > select { width: 100%; }
label.check > input, label.inline > input { width: auto; }
#trials { width: 56px; }
#speed { width: 90px; }
.icon-btn { padding: 6px 9px; line-height: 0; }
input.invalid { border-color: var(--bad); }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.row { display: flex; gap: 6px; align-items: center; margin-top: 8px; }
.row select { flex: 1; }

button {
  font: inherit; cursor: pointer;
  border: 1px solid var(--line); border-radius: 6px;
  background: var(--panel); color: var(--ink);
  padding: 6px 12px;
}
button:hover { border-color: var(--accent); }
button.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); font-weight: 600; }
button.small { padding: 3px 9px; font-size: 13px; }
button.ghost { background: transparent; }
button.icon { padding: 2px 7px; font-size: 13px; line-height: 1.2; }
button:disabled { opacity: 0.5; cursor: default; }

.item {
  border: 1px solid var(--line); border-radius: 8px;
  padding: 8px; margin-bottom: 8px; background: var(--field);
}
.item-head { display: flex; align-items: center; gap: 6px; }
.item-head input.name { flex: 1; font-weight: 600; }
.swatch { width: 14px; height: 14px; border-radius: 3px; flex-shrink: 0; border: 1px solid rgba(0,0,0,0.2); }
.field { display: flex; flex-direction: column; gap: 3px; font-size: 12px; color: var(--muted); min-width: 0; }
.field-head { display: flex; justify-content: space-between; align-items: center; }
label.auto-toggle { flex-direction: row; align-items: center; gap: 3px; font-size: 11px; cursor: pointer; }
label.auto-toggle > input { width: auto; margin: 0; }
input.auto { color: var(--muted); font-style: italic; }
.door-row { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr) minmax(0, 1fr) auto; gap: 6px; align-items: end; margin-bottom: 6px; }
.obst-row { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)) auto; gap: 4px; align-items: end; margin-bottom: 6px; }
.dims { color: var(--muted); font-size: 12px; margin-top: 4px; display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.pin { color: var(--warn); font-weight: 600; border: 1px solid currentColor; border-radius: 4px; padding: 0 4px; font-size: 11px; }
label.check.quick { margin-top: 4px; font-size: 12px; }
.quick-badge { color: var(--accent); margin-left: 4px; }
details summary { cursor: pointer; color: var(--accent); font-size: 12px; margin-top: 4px; }
details .grid3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; margin-top: 6px; }

.stage { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.toolbar {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  padding: 8px 12px; background: var(--panel); border-bottom: 1px solid var(--line);
}
.toolbar .sep { width: 1px; height: 22px; background: var(--line); }
.canvas-wrap { flex: 1; position: relative; min-height: 300px; background: var(--cv-bg); }
canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; touch-action: none; }
.busy {
  position: absolute; top: 12px; left: 50%; transform: translateX(-50%);
  display: flex; gap: 10px; align-items: center;
  background: var(--panel); border: 1px solid var(--line); border-radius: 20px;
  padding: 6px 8px 6px 14px; box-shadow: 0 2px 10px rgba(0,0,0,0.15);
}
.busy[hidden] { display: none; }
.spinner { width: 14px; height: 14px; border: 2px solid var(--line); border-top-color: var(--accent); border-radius: 50%; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.results {
  max-height: 34%; overflow-y: auto;
  background: var(--panel); border-top: 1px solid var(--line);
  padding: 10px 16px;
}
.results:empty { display: none; }
.summary { font-weight: 600; margin-bottom: 6px; }
.summary .ok { color: var(--ok); }
.summary .bad { color: var(--bad); }
.results table { border-collapse: collapse; width: 100%; font-size: 13px; }
.results td { padding: 3px 8px 3px 0; vertical-align: top; }
.results .status-ok { color: var(--ok); }
.results .status-bad { color: var(--bad); }
.results .status-warn { color: var(--warn); }
.stale { color: var(--warn); font-weight: 400; margin-left: 8px; }

@media (max-width: 800px) {
  .layout { flex-direction: column; }
  .sidebar { width: auto; border-right: 0; border-bottom: 1px solid var(--line); max-height: none; overflow: visible; }
  body { height: auto; }
  .canvas-wrap { min-height: 70vh; }
  .tagline { display: none; }
}