.container {
  display:grid;
  grid-template-columns: 20% 20% 20% 20% 20%;
  padding: 1px;
}

.greyed-out {
  text-align: center;
  border: dotted;
  color: grey;
}

.active {
  text-align:center;
  border: solid;
}

.active:hover{
  border:dashed;
}

.zero{
  grid-column: 1/ span 5;
}

div{
  font-size: 1em;
}

a {
  text-decoration:none;
  color:inherit;
}

.back {
  font-weight: bold;
  text-align:center;
  color: darkgreen;
}

.back > a {
  text-decoration:underline;
}