body {
  background-color: aliceblue;
}

header {
  background: rgb(214, 214, 214);
  border: black solid 1px;
  border-radius: 1rem;
  margin: auto;
  padding: 1rem;
  width: 50%;
}

header nav a {
  background: rgb(158, 170, 202);
  border: rgb(70, 70, 100);
  border-radius: 0.5rem;
  border-style: none solid solid none;
  border-width: 0 0.2rem 0.2rem 0;
  color: navy;
  display: block;
  font-size: 1.1rem;
  height: 20px;
  margin: 0.2rem;
  padding: 0.2rem;
  text-decoration: none;
  width: 100px;
}

header nav a:hover {
  background: whitesmoke;
  transition: background 1s, 
    height 0.5s, width 0.5s;
  width: 120px;
  height: 30px;
}

header nav a:active {
  color:#cce;
  border-width: 0 0.1rem 0.1rem 0;
}

main {
  background: white;
  width: 75%;
  margin: auto;
}

article {
  background: rgb(155, 170, 170);
  border: black solid 1px;
  border-radius: 0.5rem;
  padding: 0.2rem 1rem 0.5rem;
  margin: 0.5rem auto;
  overflow: hidden;
  height: 75px;
}

article:target {
  background: white;
  height: 200px;
  transition: all 1.5s ease-out;
}