body {
  font-family: Arial, sans-serif;
  background: #f5f5f5;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
}
.container {
  background: #fff;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  text-align: center;
  width: 90%;
  max-width: 400px;
}
h1 {
  margin-bottom: 20px;
}
button {
  display: block;
  margin: 10px auto;
  padding: 10px 20px;
  background: #3b82f6;
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
}
button:hover {
  background: #2563eb;
}
#game {
  margin-top: 20px;
}
.tic-board {
  display: grid;
  grid-template-columns: repeat(3, 80px);
  gap: 5px;
  justify-content: center;
}
.tic-cell {
  width: 80px;
  height: 80px;
  display: flex;
  justify-content: center;
  align-items: center;
  background: #e5e7eb;
  font-size: 32px;
  cursor: pointer;
}