#crt {
  background-image: url("pixel.apng");
  background-size: 2px 1px;
  background-color: #fff;
  background-blend-mode: hard-light;
  mix-blend-mode: multiply;
  pointer-events: none;
  opacity: 0.4;
}

#crt {
  position: fixed;
  width: 100%;
  top: 0;
  bottom: 0;
  right: 0;
  left: 0;
  z-index: 9999;
}

@-moz-document url-prefix() {
  #crt {
    opacity: 0.1;
  }
}