html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  font-family: "Verdana", serif;
  color: #555;
}

.hidden { display: none; }

.external::after {
  font-family: "Font Awesome 5 Free";
  font-weight: 600;
  content: "  \f35d";
  font-size: 10px;
  vertical-align: super;
}