body {
  font-family: 'Arial', sans-serif;
  background: linear-gradient(135deg, #4f46e5, #9333ea);
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0;
}

.container {
  background: #fff;
  padding: 30px;
  border-radius: 15px;
  text-align: center;
  box-shadow: 0 10px 25px rgba(0,0,0,0.3);
  width: 350px;
}

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

.mode-selection button {
  padding: 10px 15px;
  margin: 5px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  font-weight: bold;
  background: #3b82f6;
  color: white;
  transition: transform 0.2s;
}
.mode-selection button:hover {
  transform: scale(1.05);
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 100px);
  gap: 8px;
  justify-content: center;
  margin: 20px auto;
}

.cell {
  width: 100px;
  height: 100px;
  background: #f9f9f9;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 40px;
  font-weight: bold;
  cursor: pointer;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  transition: background 0.3s;
}
.cell:hover {
  background: #e0e7ff;
}

#status {
  margin: 15px 0;
  font-weight: bold;
  color: #444;
}

#restartBtn {
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  font-weight: bold;
  background: #10b981;
  color: white;
  transition: transform 0.2s;
}
#restartBtn:hover {
  transform: scale(1.05);
}