.demo4 {
  width: 100%;
  height: 700px;
  position: relative;
  overflow: hidden;
}
.demo4 #bgCanvas {
  position: absolute;
  top: 50%;
  left: 50%;
  margin-top: -540px;
  margin-left: -960px;
}
.demo4 .map-container {
  background: transparent !important;
}
.__dumi-default-previewer-demo {
  padding: 40px 24px;
  overflow: hidden;
}
.mapA .cs-map-container {
  background: transparent !important;
}
.mapB .cesium-widget canvas {
  -webkit-filter: invert(1) hue-rotate(-33deg) brightness(0.6) contrast(1) grayscale(100%) url(#change);
          filter: invert(1) hue-rotate(-33deg) brightness(0.6) contrast(1) grayscale(100%) url(#change);
}