body {
  background-color: black;
  color: white;
}

header, div, nav, footer {
  text-align: center;
}

hr {
  border: 1px solid darkgreen;
}

nav {
  display: flex;
  justify-content: space-around;
  align-items: center;
}

nav a {
  font-size: 1.5em;
  text-decoration: none;
  color: white;
  flex: 1;
}

nav a:hover {
  background-color: darkgreen;
  transition: 0.3s;
}

.active {
  background-color: darkgreen;
}

body {
  font-family: "Open Sans", sans-serif;
  font-optical-sizing: auto;
  font-weight: 300;
  font-style: normal;
  font-variation-settings:
    "wdth" 100;
}

main {
  display: flex;
  justify-content: center;
}

footer {
  color: #cfdfcd;
  font-size: 0.75em;
}

footer a {
  text-decoration: none;
  text-decoration-line: underline;
  color: white;
}

.link {
  text-decoration: none;
  text-decoration-line: underline;
  color: white;
}

.references {
  font-size: 0.75em;
}

.references a {
  text-decoration: none;
  text-decoration-line: underline;
  color: white;
}