.stop-light {
  margin-top: 2em;
  display: inline-block;
  width: 2em;
  height: 5.5em;
  border-color: black;
  border-style: solid;
  border-width: 1px;
  background-color: yellow;
} .light {
  width: 1em;
  height: 1em;
  display: inline-block;
  border-radius: 50%;
  border-color: black;
  border-width: 1px;
  border-style: solid;
  margin-left: 0.49em;
  margin-top: 0.49em;
} #greenLight.off {
  background-color: #004400;
} #yellowLight.off {
  background-color: #999900;
} #redLight.off {
  background-color: #440000;
} #greenLight.on {
  background-color: green;
} #yellowLight.on {
  background-color: yellow;
} #redLight.on {
  background-color: red;
}