body:before {
  display: block;
  content: "DEV";
  width: 300px;
  height: 10px;
  padding: 50px;
  background: rgba(255, 0, 0, 0.3);
  color: #fff;
  position: fixed;
  left: 160px;
  bottom: 0;
  text-align: center;
  z-index: 1000000;
}