.game-container {
  max-width: 700px;
  margin: auto;
  padding: 20px;
  background-color: #fff3e0;
  border-radius: 15px;
  box-shadow: 0 0 15px rgba(0,0,0,0.2);
}
h2 {
  color: #FF4081;
  font-size: 32px;
}
select, button {
  padding: 10px;
  font-size: 16px;
  margin: 10px;
  border-radius: 5px;
}
.sudoku-board {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  gap: 2px;
  margin: 20px auto;
  max-width: 360px;
}
.cell {
  width: 40px;
  height: 40px;
  text-align: center;
  font-size: 18px;
  border: 2px solid #FF9800;
  border-radius: 5px;
}
.timer, .message {
  font-size: 20px;
  margin: 10px;
}
.leaderboard {
  margin-top: 20px;
}
.correct { color: green; }
.incorrect { color: red; }
#showCorrectBtn {
  display: none;
  background-color: #2196F3;
  color: white;
  border: none;
  border-radius: 5px;
  padding: 10px 20px;
}
#finishBtn {
  background-color: #4CAF50;
  color: white;
  border: none;
  border-radius: 5px;
  padding: 10px 20px;
}