* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

.grid {
  width: 600px;
  height: 600px;
  display: flex;
  flex-wrap: wrap;
}

.square {
  border: solid 1px black;
  height: 200px;
  width: 200px;
}

.mole {
  background-color: blue;
}