* {
  box-sizing: border-box; }

body {
  font-family: Arial, sans-serif;
  color: #fff;
  background-image: linear-gradient(-90deg, #7CDBF1, #1E4C96);
  background-repeat: repeat;
  background-size: cover; }

h1 {
  text-align: center; }

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

form {
  text-align: center;
  margin: 20px; }

td, th, #error {
  padding: 3px;
  text-align: center; }

th {
  font-weight: bold;
  background-color: rgba(3, 62, 107, 0.5); }

input[name="year"] {
  width: 100px; }

input[name="submit"] {
  height: 2em;
  width: 100px;
  color: #fff;
  background-color: rgba(3, 62, 107, 0.5);
  border: 0px solid rgba(3, 62, 107, 0.5);
  border-bottom: 3px solid rgba(3, 62, 107, 0.9);
  border-right: 3px solid rgba(3, 62, 107, 0.9); }

.error {
  border-color: #ff0000; }

#calendar {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  max-width: 1000px;
  margin: 10px auto;
  background-color: rgba(0, 0, 0, 0.4); }

.month {
  display: inline-block;
  padding: 20px; }

#year-wrapper {
  font-size: 4em;
  font-weight: bold;
  text-align: center; }

td:nth-child(6), td:nth-child(7), th:nth-child(6), th:nth-child(7) {
  background-color: rgba(188, 47, 54, 0.5); }

td:nth-child(6):hover, td:nth-child(7):hover, th:nth-child(6):hover, th:nth-child(7):hover {
  background-color: #BC2F36; }

td:hover, th:hover, input[name="submit"]:hover {
  background-color: #033e6b;
  cursor: pointer; }