p {
  text-align: center;
}

form {
  margin-bottom: 1em;
  text-align: center;
}

input#birthdate {
  width: 5rem;
}

table {
  border-collapse: collapse;
  margin: 0 auto;
}

th, td {
  border: 1px solid #999;
  padding: 0.3em 0.5em;
  text-align: left;
}

th {
  background-color: #ccc;
}

tr.past td {
  background-color: #eee;
}

tr.future td {
  background-color: #ced;
}