.shader-widget-canvas {
  position: absolute; /* positioned inside parent; JS will switch to fixed for full-viewport */
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  opacity: 0.95;
  mix-blend-mode: normal;
}

/* Optional small toggle for debugging - you can remove this in production */
.shader-widget-toggle {
  position: fixed;
  right: 12px;
  bottom: 12px;
  z-index: 9999;
  background: rgba(0,0,0,0.6);
  color: #fff;
  border: none;
  padding: 8px 10px;
  font-size: 13px;
  border-radius: 6px;
}