#nav_menu {
  background:#eee;
}
#nav_menu summary {
  font-weight:bold;
  cursor:pointer;
}
#nav_menu summary:hover {
  text-decoration:underline;
}

#nav_menu ul {
  margin-top:0;
  padding-left:0;
  display:grid;
}

#nav_menu ul li {
  padding:0.618em 1.618em;
  border:2px solid transparent;
  border-radius:5px;
  margin-bottom:1px;
  color:white;
  background:#0c567c;
  font-weight:bold;
}
#nav_menu ul li.current {
  background:transparent;
  color:#666;
  border:2px solid #ccc;
}
#nav_menu ul li a{
  color:white;
}