body {
  background-color: lightgreen;
}

#countdown {
  display: none;
  margin-left: auto;
  margin-right: auto;
  margin-top: 200px;
  padding: 50px;
  font-size: 64px;
  font-family: "Arial";
  text-align: center;
  background-color: #00000033;
  min-width: 40%;
  max-width: 50%
}