body {
  font-family: Arial, sans-serif;
  padding: 20px;
  text-align: center;
}

input {
  margin: 5px;
  padding: 8px;
}

button {
  padding: 8px 12px;
  margin: 5px;
}

#calendar {
  max-width: 900px;
  margin: 40px auto;
}