html, body{
  margin: 0;
  padding: 0;
  background: black;
  font-family: 'Montserrat';
}

ul {
  font-size: 18px;
  color: rgb(219, 219, 219);
  text-align: center;
  text-decoration: none;
  list-style-type: none;
  overflow: hidden;
  margin: 0;
  padding-top: 20px;
}

li {
  float: left;
  padding: 8px 10px;
  border: 1px solid  rgb(219, 219, 219);
  border-radius: 14px; 
  margin: 0 10px;
}


li:hover{
  border: 1px solid white;
  background: white;
  color:black;
  cursor: pointer;
}

li a {
  padding: 16px;
}

.planet-facts {
  position: absolute;
  top: 20px;
  right: 30px;
  width: 450px;
  padding: 10px 20px;
  background: #fff;
  color: black;
  display: none;
  border: white;
  border-radius: 10px;
}

.planet-facts.popup {
  display: block;
}

tr{
  padding: 20px 0;
}

th, td {
  padding-right: 40px;
  text-align: left;
}

td{
  padding-bottom: 10px;
}