/* Reset & Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Poppins', sans-serif;
  background-color: #121212;
  color: #ffffff;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

/* Game Container */
.game-container {
  text-align: center;
  background: #1e1e1e;
  padding: 2rem;
  border-radius: 1rem;
  box-shadow: 0 0 20px rgba(0,0,0,0.5);
  width: 90%;
  max-width: 400px;
}

/* Heading */
.game-container h1 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
  color: #00adb5;
}

/* Board Styles */
.board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-bottom: 1.5rem;
}

.cell {
  width: 100%;
  aspect-ratio: 1 / 1;
  background-color: #2b2b2b;
  border-radius: 0.5rem;
  font-size: 2rem;
  color: #ffffff;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  transition: background 0.3s ease;
}

.cell:hover {
  background-color: #393939;
}

/* Restart Button */
#restartButton {
  background-color: #00adb5;
  border: none;
  padding: 0.75rem 1.5rem;
  color: #fff;
  font-size: 1rem;
  border-radius: 0.5rem;
  cursor: pointer;
  transition: background 0.3s ease;
}

#restartButton:hover {
  background-color: #028b91;
}

/* Responsive */
@media (max-width: 400px) {
  .game-container h1 {
    font-size: 1.5rem;
  }

  .cell {
    font-size: 1.5rem;
  }

  #restartButton {
    font-size: 0.9rem;
    padding: 0.6rem 1.2rem;
  }
}