body{
  background-image: url('aurora_borealis.jpg');
  background-size: cover;
  text-align: center;
  color: MintCream;
}

h1 {
  font-size: 2.5em;
}

p {
  font-size: 18px;
}

.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.btn {
  background-color: #FFD700;
  border: none;
  color: black;
  padding: 14px 28px;
  cursor: pointer;
  font-size: 18px;
}

table {
  border: 1px solid black;
}

th, td {
  text-align: center;
  border: 1px solid black;
  width: 120px; 
  height: 20px;
  color: black;
}

a:link {
  color: Gainsboro;
  background-color: transparent;
  text-decoration: underline;
}

a:visited {
  color: LightCoral;
  background-color: transparent;
  text-decoration: underline;
}

a:hover {
  color: red;
  background-color: transparent;
  text-decoration: underline;
}

a:active {
  color: yellow;
  background-color: transparent;
  text-decoration: underline;
}

ol {
  line-height: 2;
  text-align: left;
}

li {
  font-size: 18px;
}

footer {
  font-size: 18px;
}