* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.container {
  text-align: center;
  background: white;
  padding: 2rem;
  border-radius: 15px;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

h1 {
  color: #2c3e50;
  margin-bottom: 1rem;
  font-size: 2.5rem;
}

.status {
  margin-bottom: 1.5rem;
  font-size: 1.2rem;
  color: #34495e;
}

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

.cell {
  width: 100px;
  height: 100px;
  background: #f8f9fa;
  border-radius: 10px;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 2.5rem;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.2s ease;
  color: #2c3e50;
  border: none;
}

.cell:hover {
  background: #e9ecef;
}

.cell.x {
  color: #e74c3c;
}

.cell.o {
  color: #3498db;
}

.restart-button {
  background: #2c3e50;
  color: white;
  border: none;
  padding: 0.8rem 1.5rem;
  font-size: 1rem;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s ease;
}

.restart-button:hover {
  background: #34495e;
}

@media (max-width: 400px) {
  .cell {
    width: 80px;
    height: 80px;
    font-size: 2rem;
  }

  .container {
    padding: 1rem;
  }

  h1 {
    font-size: 2rem;
  }
}