html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background-color: #000;
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: Arial, Helvetica, sans-serif;
}

#countdown {
  color: #ffffff;
  font-size: 4rem;
  letter-spacing: 0.15em;
  text-align: center;
}