html {
  padding:0;
  margin:0;
  height:100%;
  background-color:white;
  color:black;
  font-size:1.5rem;
}
body {
  padding:0;
  margin:0;
  width:100%;
  height:100%;
}
a {
  text-decoration:none;
}
a:hover {
  text-decoration:underline;
}
main {
  margin:1rem;
}

.header {
  margin:0;
  padding:1rem;
  background-color:#0000ff;
  color:white;
  font-size:2rem;
}
.header a {
  color:white;
}

.link a {
  display:block;
  padding:1rem;
}
.link a:hover {
  background-color:white;
  filter:invert(1);
  text-decoration:none;
}