body
{
  background-color: #000;
  padding: 20px;
  font-family: Calibri, Arial, sans-serif;
}

a:link {
  color: yellow;
}

a:visited {
  color: orange;
}

a:hover {
  color: hotpink;
}

.Header {
  text-align: center;
}

a img {
  border: 2px solid rgba(0,0,0,1);
}

a img:hover {
  border: 2px solid yellow;
}