body {
  font-family: 'Arial', sans-serif;
  text-align: center;
  background-color: #f0f0f0;
}

#game-container {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: 20px;
}

#grid {
  width: 300px;
  height: 300px;
  display: grid;
  grid-template-columns: repeat(10, 30px);
  grid-template-rows: repeat(10, 30px);
  background-color: #ddd;
  border: 2px solid #333;
}

.cell {
  width: 30px;
  height: 30px;
  border: 1px solid #999;
  box-sizing: border-box;
}

.filled {
  background-color: #3498db;
}

.block {
  margin-bottom: 10px;
  cursor: grab;
}

.preview {
  background-color: rgba(52, 152, 219, 0.4);
}