body {
  font-family: Arial, sans-serif;
  background: #f4f4f4;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 40px;
}

h1 {
  margin-bottom: 20px;
  color: #333;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 100px);
  grid-template-rows: repeat(3, 100px);
  gap: 5px;
}

.cell {
  background: #fff;
  border: 2px solid #333;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 48px;
  font-weight: bold;
  cursor: pointer;
  transition: background 0.3s ease;
}

.cell:hover {
  background: #e0e0e0;
}