/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");

/**** 
* Classes
****/ 
var GameGrid = Container.expand(function () {
	var self = Container.call(this);
	self.gridSize = 4;
	self.cellSize = 120;
	self.cellGap = 10;
	self.grid = [];
	self.tiles = [];
	self.isAnimating = false;
	// Initialize grid array
	for (var i = 0; i < self.gridSize; i++) {
		self.grid[i] = [];
		for (var j = 0; j < self.gridSize; j++) {
			self.grid[i][j] = null;
		}
	}
	// Create visual grid background
	var gridBg = self.attachAsset('gridBackground', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.getCellX = function (col) {
		return (col - 1.5) * (self.cellSize + self.cellGap);
	};
	self.getCellY = function (row) {
		return (row - 1.5) * (self.cellSize + self.cellGap);
	};
	// Create grid cells
	for (var i = 0; i < self.gridSize; i++) {
		for (var j = 0; j < self.gridSize; j++) {
			var cell = LK.getAsset('gridCell', {
				anchorX: 0.5,
				anchorY: 0.5
			});
			cell.x = self.getCellX(j);
			cell.y = self.getCellY(i);
			self.addChild(cell);
		}
	}
	self.addTile = function (value, row, col) {
		var tile = new Tile(value);
		tile.gridX = col;
		tile.gridY = row;
		tile.x = self.getCellX(col);
		tile.y = self.getCellY(row);
		self.grid[row][col] = tile;
		self.tiles.push(tile);
		self.addChild(tile);
		// Spawn animation
		tile.scaleX = 0;
		tile.scaleY = 0;
		tween(tile, {
			scaleX: 1,
			scaleY: 1
		}, {
			duration: 200,
			easing: tween.easeOut
		});
		return tile;
	};
	self.removeTile = function (tile) {
		var row = tile.gridY;
		var col = tile.gridX;
		self.grid[row][col] = null;
		var index = self.tiles.indexOf(tile);
		if (index > -1) {
			self.tiles.splice(index, 1);
		}
		self.removeChild(tile);
	};
	self.getEmptyCells = function () {
		var emptyCells = [];
		for (var i = 0; i < self.gridSize; i++) {
			for (var j = 0; j < self.gridSize; j++) {
				if (self.grid[i][j] === null) {
					emptyCells.push({
						row: i,
						col: j
					});
				}
			}
		}
		return emptyCells;
	};
	self.spawnRandomTile = function () {
		var emptyCells = self.getEmptyCells();
		if (emptyCells.length === 0) return false;
		var randomCell = emptyCells[Math.floor(Math.random() * emptyCells.length)];
		var value = Math.random() < 0.9 ? 2 : 4;
		self.addTile(value, randomCell.row, randomCell.col);
		return true;
	};
	self.canMove = function () {
		// Check for empty cells
		if (self.getEmptyCells().length > 0) return true;
		// Check for possible merges
		for (var i = 0; i < self.gridSize; i++) {
			for (var j = 0; j < self.gridSize; j++) {
				var current = self.grid[i][j];
				if (current) {
					// Check right
					if (j < self.gridSize - 1 && self.grid[i][j + 1] && self.grid[i][j + 1].value === current.value) {
						return true;
					}
					// Check down
					if (i < self.gridSize - 1 && self.grid[i + 1][j] && self.grid[i + 1][j].value === current.value) {
						return true;
					}
				}
			}
		}
		return false;
	};
	self.move = function (direction, callback) {
		if (self.isAnimating) return false;
		var moved = false;
		var merges = [];
		self.isAnimating = true;
		// Reset merge flags
		for (var i = 0; i < self.tiles.length; i++) {
			self.tiles[i].justMerged = false;
		}
		if (direction === 'left') {
			for (var row = 0; row < self.gridSize; row++) {
				var line = [];
				for (var col = 0; col < self.gridSize; col++) {
					if (self.grid[row][col]) {
						line.push(self.grid[row][col]);
						self.grid[row][col] = null;
					}
				}
				var newLine = self.mergeLine(line);
				for (var i = 0; i < newLine.length; i++) {
					if (newLine[i]) {
						var tile = newLine[i];
						var oldCol = tile.gridX;
						var newCol = i;
						if (oldCol !== newCol || tile.justMerged) {
							moved = true;
						}
						tile.gridX = newCol;
						tile.gridY = row;
						self.grid[row][newCol] = tile;
						if (tile.justMerged) {
							merges.push(tile);
						}
					}
				}
			}
		} else if (direction === 'right') {
			for (var row = 0; row < self.gridSize; row++) {
				var line = [];
				for (var col = self.gridSize - 1; col >= 0; col--) {
					if (self.grid[row][col]) {
						line.push(self.grid[row][col]);
						self.grid[row][col] = null;
					}
				}
				var newLine = self.mergeLine(line);
				for (var i = 0; i < newLine.length; i++) {
					if (newLine[i]) {
						var tile = newLine[i];
						var oldCol = tile.gridX;
						var newCol = self.gridSize - 1 - i;
						if (oldCol !== newCol || tile.justMerged) {
							moved = true;
						}
						tile.gridX = newCol;
						tile.gridY = row;
						self.grid[row][newCol] = tile;
						if (tile.justMerged) {
							merges.push(tile);
						}
					}
				}
			}
		} else if (direction === 'up') {
			for (var col = 0; col < self.gridSize; col++) {
				var line = [];
				for (var row = 0; row < self.gridSize; row++) {
					if (self.grid[row][col]) {
						line.push(self.grid[row][col]);
						self.grid[row][col] = null;
					}
				}
				var newLine = self.mergeLine(line);
				for (var i = 0; i < newLine.length; i++) {
					if (newLine[i]) {
						var tile = newLine[i];
						var oldRow = tile.gridY;
						var newRow = i;
						if (oldRow !== newRow || tile.justMerged) {
							moved = true;
						}
						tile.gridX = col;
						tile.gridY = newRow;
						self.grid[newRow][col] = tile;
						if (tile.justMerged) {
							merges.push(tile);
						}
					}
				}
			}
		} else if (direction === 'down') {
			for (var col = 0; col < self.gridSize; col++) {
				var line = [];
				for (var row = self.gridSize - 1; row >= 0; row--) {
					if (self.grid[row][col]) {
						line.push(self.grid[row][col]);
						self.grid[row][col] = null;
					}
				}
				var newLine = self.mergeLine(line);
				for (var i = 0; i < newLine.length; i++) {
					if (newLine[i]) {
						var tile = newLine[i];
						var oldRow = tile.gridY;
						var newRow = self.gridSize - 1 - i;
						if (oldRow !== newRow || tile.justMerged) {
							moved = true;
						}
						tile.gridX = col;
						tile.gridY = newRow;
						self.grid[newRow][col] = tile;
						if (tile.justMerged) {
							merges.push(tile);
						}
					}
				}
			}
		}
		if (moved) {
			// Animate tiles to new positions
			var animatingTiles = 0;
			for (var i = 0; i < self.tiles.length; i++) {
				var tile = self.tiles[i];
				var targetX = self.getCellX(tile.gridX);
				var targetY = self.getCellY(tile.gridY);
				if (tile.x !== targetX || tile.y !== targetY) {
					animatingTiles++;
					tile.animateMoveTo(targetX, targetY, function () {
						animatingTiles--;
						if (animatingTiles === 0) {
							// All animations complete
							for (var j = 0; j < merges.length; j++) {
								merges[j].animateMerge();
								LK.getSound('merge').play();
							}
							self.isAnimating = false;
							if (callback && typeof callback === 'function') callback(true);
						}
					});
				}
			}
			if (animatingTiles === 0) {
				self.isAnimating = false;
				if (callback && typeof callback === 'function') callback(true);
			}
			if (merges.length === 0) {
				LK.getSound('slide').play();
			}
		} else {
			self.isAnimating = false;
			if (callback && typeof callback === 'function') callback(false);
		}
		return moved;
	};
	self.mergeLine = function (line) {
		var result = [];
		var i = 0;
		while (i < line.length) {
			if (i < line.length - 1 && line[i].value === line[i + 1].value) {
				// Merge tiles
				var newValue = line[i].value * 2;
				line[i].setValue(newValue);
				line[i].justMerged = true;
				LK.setScore(LK.getScore() + newValue);
				// Remove the second tile
				self.removeTile(line[i + 1]);
				result.push(line[i]);
				i += 2;
			} else {
				result.push(line[i]);
				i++;
			}
		}
		return result;
	};
	return self;
});
var Tile = Container.expand(function (value) {
	var self = Container.call(this);
	self.value = value;
	self.gridX = 0;
	self.gridY = 0;
	self.isMoving = false;
	self.justMerged = false;
	function getTileAssetId(value) {
		return 'tile' + value;
	}
	function getTileColor(value) {
		if (value <= 4) return 0x776E65;
		return 0xF9F6F2;
	}
	var tileGraphics = self.attachAsset(getTileAssetId(value), {
		anchorX: 0.5,
		anchorY: 0.5
	});
	var tileText = new Text2(value.toString(), {
		size: value >= 128 ? 40 : value >= 32 ? 50 : 60,
		fill: getTileColor(value)
	});
	tileText.anchor.set(0.5, 0.5);
	self.addChild(tileText);
	self.setValue = function (newValue) {
		self.value = newValue;
		self.removeChild(tileGraphics);
		tileGraphics = self.attachAsset(getTileAssetId(newValue), {
			anchorX: 0.5,
			anchorY: 0.5
		});
		self.addChildAt(tileGraphics, 0);
		tileText.setText(newValue.toString());
		tileText.style.fontSize = newValue >= 128 ? 40 : newValue >= 32 ? 50 : 60;
		tileText.style.fill = getTileColor(newValue);
		// Pop animation for new value
		self.scaleX = 1.2;
		self.scaleY = 1.2;
		tween(self, {
			scaleX: 1,
			scaleY: 1
		}, {
			duration: 200,
			easing: tween.easeOut
		});
	};
	self.animateMoveTo = function (x, y, callback) {
		self.isMoving = true;
		tween(self, {
			x: x,
			y: y
		}, {
			duration: 150,
			easing: tween.easeOut,
			onFinish: function onFinish() {
				self.isMoving = false;
				if (callback && typeof callback === 'function') callback();
			}
		});
	};
	self.animateMerge = function () {
		self.scaleX = 1.1;
		self.scaleY = 1.1;
		tween(self, {
			scaleX: 1,
			scaleY: 1
		}, {
			duration: 100,
			easing: tween.easeOut
		});
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000000
});

/**** 
* Game Code
****/ 
var gameGrid;
var scoreTxt;
var bestTxt;
var gameWon = false;
var gameOver = false;
var touchStartX = 0;
var touchStartY = 0;
var minSwipeDistance = 30;
// Initialize score display
scoreTxt = new Text2('0', {
	size: 60,
	fill: 0x776E65
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
scoreTxt.y = 100;
// Create and position game grid
gameGrid = new GameGrid();
gameGrid.x = 2048 / 2;
gameGrid.y = 2732 / 2;
game.addChild(gameGrid);
// Spawn initial tiles
gameGrid.spawnRandomTile();
gameGrid.spawnRandomTile();
// Update score display
scoreTxt.setText('Score: ' + LK.getScore());
// Touch/swipe handling
game.down = function (x, y, obj) {
	if (gameOver || gameWon) return;
	touchStartX = x;
	touchStartY = y;
};
game.up = function (x, y, obj) {
	if (gameOver || gameWon || gameGrid.isAnimating) return;
	var deltaX = x - touchStartX;
	var deltaY = y - touchStartY;
	var absDeltaX = Math.abs(deltaX);
	var absDeltaY = Math.abs(deltaY);
	if (Math.max(absDeltaX, absDeltaY) < minSwipeDistance) return;
	var direction;
	if (absDeltaX > absDeltaY) {
		direction = deltaX > 0 ? 'right' : 'left';
	} else {
		direction = deltaY > 0 ? 'down' : 'up';
	}
	gameGrid.move(direction, function (moved) {
		if (moved) {
			scoreTxt.setText('Score: ' + LK.getScore());
			// Check for 2048 tile (win condition)
			if (!gameWon) {
				for (var i = 0; i < gameGrid.tiles.length; i++) {
					if (gameGrid.tiles[i].value === 2048) {
						gameWon = true;
						LK.setTimeout(function () {
							LK.showYouWin();
						}, 500);
						return;
					}
				}
			}
			// Spawn new tile
			if (!gameGrid.spawnRandomTile()) {
				// Grid is full, check if game over
				if (!gameGrid.canMove()) {
					gameOver = true;
					LK.setTimeout(function () {
						LK.showGameOver();
					}, 500);
				}
			}
		}
	});
};
game.update = function () {
	// Game loop updates handled by other systems
};

===================================================================
--- original.js
+++ change.js
@@ -372,9 +372,9 @@
 /**** 
 * Initialize Game
 ****/ 
 var game = new LK.Game({
-	backgroundColor: 0xFAF8EF
+	backgroundColor: 0x000000
 });
 
 /**** 
 * Game Code