.iir-wrap {
  max-width: 1100px;
  margin: 0 auto;
  font-family: system-ui, sans-serif;
}
.iir-toolbar {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
  margin: 10px 0 16px;
}
.iir-btn {
  background: #f0f0f1;
  border: 1px solid #c3c4c7;
  border-radius: 6px;
  padding: 6px 10px;
  cursor: pointer;
  user-select: none;
}
.iir-primary {
  background: #2271b1;
  border: 1px solid #135e96;
  color: #fff;
  border-radius: 6px;
  padding: 8px 12px;
  cursor: pointer;
}
.iir-primary[disabled],
.iir-secondary[disabled],
.iir-btn[disabled] {
  opacity: 0.5;
  cursor: not-allowed;
}
.iir-secondary {
  background: #fff;
  border: 1px solid #2271b1;
  color: #2271b1;
  border-radius: 6px;
  padding: 8px 12px;
  cursor: pointer;
}
.iir-slider {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0 8px;
}

.iir-canvas-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
.iir-canvas-col h3 {
  margin: 6px 0 8px;
}

.iir-stage {
  position: relative;
  width: 100%;
  max-width: 900px;
  border: 1px dashed #c3c4c7;
  border-radius: 6px;
  background: #fafafa;
  overflow: auto;
}

#iir-canvas, #iir-mask, #iir-cursor, #iir-result {
  max-width: 100%;
  display: block;
}
#iir-canvas { position: relative; z-index: 1; }
#iir-mask   { position: absolute; inset: 0; z-index: 2; cursor: crosshair; }
#iir-cursor { position: absolute; inset: 0; z-index: 3; pointer-events: none; }

.iir-hint {
  color: #555;
  font-size: 12px;
  margin: 6px 0 0;
}
.iir-status {
  margin-top: 12px;
  font-size: 12px;
  color: #1d2327;
}