* { box-sizing: border-box; }
body { margin: 0; font-family: "Segoe UI", Tahoma, sans-serif; background: #f1f1f1; color: #222; }
.app { display: grid; grid-template-columns: 1fr 360px; height: 100vh; }
.canvas-pane { position: relative; margin: 12px; background: #fff; border-radius: 12px; overflow: hidden; touch-action: none; }
#boardCanvas { width: 100%; height: 100%; display: block; background: #111; touch-action: none; }
#canvasHint { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; color: #666; font-size: 20px; }
.side-pane { margin: 12px 12px 12px 0; background: #fff; border-radius: 12px; padding: 12px; overflow: auto; }
section { margin-bottom: 16px; }
section h3 { margin: 8px 0; font-size: 16px; }
.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
label { display: block; font-size: 13px; margin-bottom: 8px; }
input[type="text"], select { width: 100%; padding: 6px; }
input[type="file"]#mbpInput { display: none; }
button { padding: 8px; cursor: pointer; }
#status { color: #555; font-size: 13px; }
#listPanel { border: 1px solid #ddd; border-radius: 8px; padding: 8px; background: #fafafa; }
.list-title { font-size: 12px; font-weight: 600; margin: 6px 0; }
.list-body { display: grid; gap: 4px; max-height: 180px; overflow: auto; padding-bottom: 4px; }
.list-row { display: grid; grid-template-columns: 1fr 80px 50px; gap: 6px; align-items: center; font-size: 12px; background: #fff; border: 1px solid #e5e5e5; border-radius: 6px; padding: 4px 6px; cursor: pointer; }
.list-row small { color: #777; }
.list-row.active { border-color: #1e88e5; background: #e9f2ff; }

@media (max-width: 900px) {
  .app { grid-template-columns: 1fr; grid-template-rows: 60vh auto; height: 100vh; }
  .side-pane { margin: 0 12px 12px; }
  .canvas-pane { margin: 12px; }
}