body {
  font-family: Arial, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.grid {
  display: grid;
  grid-template-columns: repeat(5, 50px);
  grid-template-rows: repeat(5, 50px);
  gap: 5px;
}

.grid-cell {
  width: 50px;
  height: 50px;
  background-color: lightgrey;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 24px;
  cursor: pointer;
}

.highlight {
  background-color: lightgreen;
}