body {
  font-family: sans-serif;
  text-align: center;
  background: #f9f9f9;
}

#grid {
  display: grid;
  grid-template-columns: repeat(5, 40px);
  grid-gap: 5px;
  justify-content: center;
  margin: 20px 0;
}

.cell {
  width: 40px;
  height: 40px;
  border: 1px solid #ccc;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: white;
  font-weight: bold;
}

.player {
  background-color: lightblue;
}

.x {
  background-color: lightgreen;
}

#controls button {
  margin: 5px;
  padding: 10px;
  font-size: 16px;
}