.symbol {
  display: inline-block;
  border-radius: 50%;
  border: 5px double white;
  width: 40px;
  height: 40px;
  /*margin: 0px 10px 0px 10px;*/
}

.symbol-empty {
  background-color: #ccc;
}

.symbol-filled {
  background-color: orange;
}