body {
  background: #000;
  color: #fff;
  font-family: "Times New Roman", Times, serif;
  margin: 0;
  padding: 0;
  transition: background-color 0.5s, color 0.5s;
}

body.light {
  background: #fff;
  color: #000;
}

#arrival,
#elapsed-container {
  text-align: center;
  margin-top: 50px;
}

h1,
h2 {
  font-size: 60px;
  margin-bottom: 20px;
}

#countdown,
#elapsed {
  font-size: 80px;
  margin-top: 20px;
}

#theme {
  position: absolute;
  right: 30px;
  top: 30px;
  background-color: #fff;
  color: #000;
  border: 1px solid #000;
  border-radius: 5px;
  padding: 5px 15px;
  cursor: pointer;
  font-size: 18px;
  transition: background-color 0.5s, color 0.5s;
  font-family: "Times New Roman", Times, serif;
}

#theme:hover {
  background: #000;
  color: #fff;
}

@media screen and (max-width: 575px) {
  h1,
  h2 {
    font-size: 35px;
  }

  #countdown,
  #elapsed {
    font-size: 44px;
  }

  #theme {
    font-size: 16px;
    top: 15px;
    right: 15px;
  }
}