body {
  font-family: Arial, sans-serif;
  text-align: center;
  transition: background 0.5s, color 0.5s;
  padding-top: 80px;
}
.container {
  margin: auto;
  width: 300px;
}
#timer {
  font-size: 3rem;
  margin: 20px 0;
}
button {
  padding: 10px 20px;
  margin: 5px;
  cursor: pointer;
  border-radius: 8px;
  border: none;
}
@media (prefers-color-scheme: dark) {
  body {
    background: #0d0d0d;
    color: #ff7518;
  }
  #title {
    text-shadow: 0 0 10px purple;
  }
}