remove use of class list in actuator, fix animations for firefox
remove use of class list in actuator, fix animations for firefox

file:b/.jshintrc (new)
--- /dev/null
+++ b/.jshintrc
@@ -1,1 +1,20 @@
+{
+    "esnext": true,
+    "indent": 2,
+    "maxlen": 80,
+    "freeze": true,
+    "camelcase": true,
+    "unused": true,
+    "eqnull": true,
+    "proto": true,
+    "supernew": true,
+    "noyield": true,
+    "evil": true,
+    "node": true,
+    "boss": true,
+    "expr": true,
+    "loopfunc": true,
+    "white": true,
+    "maxdepth": 4
+}
 

file:a/README.md -> file:b/README.md
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # 2048
 A small clone of [1024](https://play.google.com/store/apps/details?id=com.veewo.a1024), based on [Saming's 2048](saming.fr/p/2048/) (also a clone).
 
-Made just for fun.
+Made just for fun. [Play it here!](http://gabrielecirulli.github.io/2048/)
 
-[![Screenshot](http://pictures.gabrielecirulli.com/2048-20140305-170629.png)](http://pictures.gabrielecirulli.com/2048-20140305-170629.png)
+[![Screenshot](http://pictures.gabrielecirulli.com/2048-20140309-234100.png)](http://pictures.gabrielecirulli.com/2048-20140309-234100.png)
 

file:a/index.html -> file:b/index.html
--- a/index.html
+++ b/index.html
@@ -5,12 +5,30 @@
   <title>2048</title>
 
   <link href="style/main.css" rel="stylesheet" type="text/css">
+
+  <script src="js/keyboard_input_manager.js"></script>
+  <script src="js/html_actuator.js"></script>
+  <script src="js/grid.js"></script>
+  <script src="js/tile.js"></script>
+  <script src="js/game_manager.js"></script>
+  <script src="js/application.js"></script>
 </head>
 <body>
   <div class="container">
-    <h1>2048</h1>
+    <div class="heading">
+      <h1 class="title">2048</h1>
+      <div class="score-container">0</div>
+    </div>
+    <p class="game-intro">Join the numbers and get to the <strong>2048 tile!</strong></p>
 
     <div class="game-container">
+      <div class="game-message">
+        <p></p>
+        <div class="lower">
+          <a class="retry-button">Try again</a>
+        </div>
+      </div>
+
       <div class="grid-container">
         <div class="grid-row">
           <div class="grid-cell"></div>
@@ -39,41 +57,17 @@
       </div>
 
       <div class="tile-container">
-        <div class="tile tile-2 tile-position-1-1">
-          2
-        </div>
-        <div class="tile tile-4 tile-position-2-1">
-          4
-        </div>
-        <div class="tile tile-8 tile-position-3-1">
-          8
-        </div>
-        <div class="tile tile-16 tile-position-4-1">
-          16
-        </div>
-        <div class="tile tile-32 tile-position-1-2">
-          32
-        </div>
-        <div class="tile tile-64 tile-position-2-2">
-          64
-        </div>
-        <div class="tile tile-128 tile-position-3-2">
-          128
-        </div>
-        <div class="tile tile-256 tile-position-4-2">
-          256
-        </div>
-        <div class="tile tile-512 tile-position-1-3">
-          512
-        </div>
-        <div class="tile tile-1024 tile-position-2-3">
-          1024
-        </div>
-        <div class="tile tile-2048 tile-position-3-3">
-          2048
-        </div>
+
       </div>
     </div>
+
+    <p class="game-explanation">
+      <strong class="important">How to play:</strong> Use your <strong>arrow keys</strong> to move the tiles. When two tiles with the same number touch, they <strong>merge into one!</strong>
+    </p>
+    <hr>
+    <p>
+      Created by <a href="http://gabrielecirulli.com" target="_blank">Gabriele Cirulli.</a> Based on <a href="https://itunes.apple.com/us/app/1024!/id823499224" target="_blank">1024 by Veewo Studio.</a>
+    </p>
   </div>
 </body>
 </html>

file:b/js/application.js (new)
--- /dev/null
+++ b/js/application.js
@@ -1,1 +1,7 @@
+document.addEventListener("DOMContentLoaded", function () {
+  // Wait till the browser is ready to render the game (avoids glitches)
+  window.requestAnimationFrame(function () {
+    var manager = new GameManager(4, KeyboardInputManager, HTMLActuator);
+  });
+});
 

--- /dev/null
+++ b/js/game_manager.js
@@ -1,1 +1,224 @@
-
+function GameManager(size, InputManager, Actuator) {
+  this.size         = size; // Size of the grid
+  this.inputManager = new InputManager;
+  this.actuator     = new Actuator;
+
+  this.startTiles   = 2;
+
+  this.inputManager.on("move", this.move.bind(this));
+  this.inputManager.on("restart", this.restart.bind(this));
+
+  this.setup();
+}
+
+// Restart the game
+GameManager.prototype.restart = function () {
+  this.actuator.restart();
+  this.setup();
+};
+
+// Set up the game
+GameManager.prototype.setup = function () {
+  this.grid         = new Grid(this.size);
+
+  this.score        = 0;
+  this.over         = false;
+  this.won          = false;
+
+  // Add the initial tiles
+  this.addStartTiles();
+
+  // Update the actuator
+  this.actuate();
+};
+
+// Set up the initial tiles to start the game with
+GameManager.prototype.addStartTiles = function () {
+  for (var i = 0; i < this.startTiles; i++) {
+    this.addRandomTile();
+  }
+};
+
+// Adds a tile in a random position
+GameManager.prototype.addRandomTile = function () {
+  if (this.grid.cellsAvailable()) {
+    var value = Math.random() < 0.9 ? 2 : 4;
+    var tile = new Tile(this.grid.randomAvailableCell(), value);
+
+    this.grid.insertTile(tile);
+  }
+};
+
+// Sends the updated grid to the actuator
+GameManager.prototype.actuate = function () {
+  this.actuator.actuate(this.grid, {
+    score: this.score,
+    over:  this.over,
+    won:   this.won
+  });
+};
+
+// Save all tile positions and remove merger info
+GameManager.prototype.prepareTiles = function () {
+  this.grid.eachCell(function (x, y, tile) {
+    if (tile) {
+      tile.mergedFrom = null;
+      tile.savePosition();
+    }
+  });
+};
+
+// Move a tile and its representation
+GameManager.prototype.moveTile = function (tile, cell) {
+  this.grid.cells[tile.x][tile.y] = null;
+  this.grid.cells[cell.x][cell.y] = tile;
+  tile.updatePosition(cell);
+};
+
+// Move tiles on the grid in the specified direction
+GameManager.prototype.move = function (direction) {
+  // 0: up, 1: right, 2:down, 3: left
+  var self = this;
+
+  if (this.over || this.won) return; // Don't do anything if the game's over
+
+  var cell, tile;
+
+  var vector     = this.getVector(direction);
+  var traversals = this.buildTraversals(vector);
+  var moved      = false;
+
+  // Save the current tile positions and remove merger information
+  this.prepareTiles();
+
+  // Traverse the grid in the right direction and move tiles
+  traversals.x.forEach(function (x) {
+    traversals.y.forEach(function (y) {
+      cell = { x: x, y: y };
+      tile = self.grid.cellContent(cell);
+
+      if (tile) {
+        var positions = self.findFarthestPosition(cell, vector);
+        var next      = self.grid.cellContent(positions.next);
+
+        // Only one merger per row traversal?
+        if (next && next.value === tile.value && !next.mergedFrom) {
+          var merged = new Tile(positions.next, tile.value * 2);
+          merged.mergedFrom = [tile, next];
+
+          self.grid.insertTile(merged);
+          self.grid.removeTile(tile);
+
+          // Converge the two tiles' positions
+          tile.updatePosition(positions.next);
+
+          // Update the score
+          self.score += merged.value;
+
+          // The mighty 2048 tile
+          if (merged.value === 2048) self.won = true;
+        } else {
+          self.moveTile(tile, positions.farthest);
+        }
+
+        if (!self.positionsEqual(cell, tile)) {
+          moved = true; // The tile moved from its original cell!
+        }
+      }
+    });
+  });
+
+  if (moved) {
+    this.addRandomTile();
+
+    if (!this.movesAvailable()) {
+      this.over = true; // Game over!
+    }
+
+    this.actuate();
+  }
+};
+
+// Get the vector representing the chosen direction
+GameManager.prototype.getVector = function (direction) {
+  // Vectors representing tile movement
+  var map = {
+    0: { x: 0,  y: -1 }, // up
+    1: { x: 1,  y: 0 },  // right
+    2: { x: 0,  y: 1 },  // down
+    3: { x: -1, y: 0 }   // left
+  };
+
+  return map[direction];
+};
+
+// Build a list of positions to traverse in the right order
+GameManager.prototype.buildTraversals = function (vector) {
+  var traversals = { x: [], y: [] };
+
+  for (var pos = 0; pos < this.size; pos++) {
+    traversals.x.push(pos);
+    traversals.y.push(pos);
+  }
+
+  // Always traverse from the farthest cell in the chosen direction
+  if (vector.x === 1) traversals.x = traversals.x.reverse();
+  if (vector.y === 1) traversals.y = traversals.y.reverse();
+
+  return traversals;
+};
+
+GameManager.prototype.findFarthestPosition = function (cell, vector) {
+  var previous;
+
+  // Progress towards the vector direction until an obstacle is found
+  do {
+    previous = cell;
+    cell     = { x: previous.x + vector.x, y: previous.y + vector.y };
+  } while (this.grid.withinBounds(cell) &&
+           this.grid.cellAvailable(cell));
+
+  return {
+    farthest: previous,
+    next: cell // Used to check if a merge is required
+  };
+};
+
+GameManager.prototype.movesAvailable = function () {
+  return this.grid.cellsAvailable() || this.tileMatchesAvailable();
+};
+
+// Check for available matches between tiles (more expensive check)
+GameManager.prototype.tileMatchesAvailable = function () {
+  var self = this;
+
+  var tile;
+
+  for (var x = 0; x < this.size; x++) {
+    for (var y = 0; y < this.size; y++) {
+      tile = this.grid.cellContent({ x: x, y: y });
+
+      if (tile) {
+        for (var direction = 0; direction < 4; direction++) {
+          var vector = self.getVector(direction);
+          var cell   = { x: x + vector.x, y: y + vector.y };
+
+          var other  = self.grid.cellContent(cell);
+          if (other) {
+          }
+
+          if (other && other.value === tile.value) {
+            return true; // These two tiles can be merged
+          }
+        }
+      }
+    }
+  }
+
+  return false;
+};
+
+GameManager.prototype.positionsEqual = function (first, second) {
+  return first.x === second.x && first.y === second.y;
+};
+

file:b/js/grid.js (new)
--- /dev/null
+++ b/js/grid.js
@@ -1,1 +1,85 @@
+function Grid(size) {
+  this.size = size;
 
+  this.cells = [];
+
+  this.build();
+}
+
+// Build a grid of the specified size
+Grid.prototype.build = function () {
+  for (var x = 0; x < this.size; x++) {
+    var row = this.cells[x] = [];
+
+    for (var y = 0; y < this.size; y++) {
+      row.push(null);
+    }
+  }
+};
+
+// Find the first available random position
+Grid.prototype.randomAvailableCell = function () {
+  var cells = this.availableCells();
+
+  if (cells.length) {
+    return cells[Math.floor(Math.random() * cells.length)];
+  }
+};
+
+Grid.prototype.availableCells = function () {
+  var cells = [];
+
+  this.eachCell(function (x, y, tile) {
+    if (!tile) {
+      cells.push({ x: x, y: y });
+    }
+  });
+
+  return cells;
+};
+
+// Call callback for every cell
+Grid.prototype.eachCell = function (callback) {
+  for (var x = 0; x < this.size; x++) {
+    for (var y = 0; y < this.size; y++) {
+      callback(x, y, this.cells[x][y]);
+    }
+  }
+};
+
+// Check if there are any cells available
+Grid.prototype.cellsAvailable = function () {
+  return !!this.availableCells().length;
+};
+
+// Check if the specified cell is taken
+Grid.prototype.cellAvailable = function (cell) {
+  return !this.cellOccupied(cell);
+};
+
+Grid.prototype.cellOccupied = function (cell) {
+  return !!this.cellContent(cell);
+};
+
+Grid.prototype.cellContent = function (cell) {
+  if (this.withinBounds(cell)) {
+    return this.cells[cell.x][cell.y];
+  } else {
+    return null;
+  }
+};
+
+// Inserts a tile at its position
+Grid.prototype.insertTile = function (tile) {
+  this.cells[tile.x][tile.y] = tile;
+};
+
+Grid.prototype.removeTile = function (tile) {
+  this.cells[tile.x][tile.y] = null;
+};
+
+Grid.prototype.withinBounds = function (position) {
+  return position.x >= 0 && position.x < this.size &&
+         position.y >= 0 && position.y < this.size;
+};
+

--- /dev/null
+++ b/js/html_actuator.js
@@ -1,1 +1,117 @@
+function HTMLActuator() {
+  this.tileContainer    = document.getElementsByClassName("tile-container")[0];
+  this.scoreContainer   = document.getElementsByClassName("score-container")[0];
+  this.messageContainer = document.getElementsByClassName("game-message")[0];
 
+  this.score = 0;
+}
+
+HTMLActuator.prototype.actuate = function (grid, metadata) {
+  var self = this;
+
+  window.requestAnimationFrame(function () {
+    self.clearContainer(self.tileContainer);
+
+    grid.cells.forEach(function (column) {
+      column.forEach(function (cell) {
+        if (cell) {
+          self.addTile(cell);
+        }
+      });
+    });
+
+    self.updateScore(metadata.score);
+
+    if (metadata.over) self.message(false); // You lose
+    if (metadata.won) self.message(true); // You win!
+  });
+};
+
+HTMLActuator.prototype.restart = function () {
+  this.clearMessage();
+};
+
+HTMLActuator.prototype.clearContainer = function (container) {
+  while (container.firstChild) {
+    container.removeChild(container.firstChild);
+  }
+};
+
+HTMLActuator.prototype.addTile = function (tile) {
+  var self = this;
+
+  var element   = document.createElement("div");
+  var position  = tile.previousPosition || { x: tile.x, y: tile.y };
+  positionClass = this.positionClass(position);
+
+  // We can't use classlist because it somehow glitches when replacing classes
+  var classes = ["tile", "tile-" + tile.value, positionClass];
+  this.applyClasses(element, classes);
+
+  element.textContent = tile.value;
+
+  if (tile.previousPosition) {
+    // Make sure that the tile gets rendered in the previous position first
+    window.requestAnimationFrame(function () {
+      classes[2] = self.positionClass({ x: tile.x, y: tile.y });
+      self.applyClasses(element, classes); // Update the position
+    });
+  } else if (tile.mergedFrom) {
+    classes.push("tile-merged");
+    this.applyClasses(element, classes);
+
+    // Render the tiles that merged
+    tile.mergedFrom.forEach(function (merged) {
+      self.addTile(merged);
+    });
+  } else {
+    classes.push("tile-new");
+    this.applyClasses(element, classes);
+  }
+
+  // Put the tile on the board
+  this.tileContainer.appendChild(element);
+};
+
+HTMLActuator.prototype.applyClasses = function (element, classes) {
+  element.setAttribute("class", classes.join(" "));
+};
+
+HTMLActuator.prototype.normalizePosition = function (position) {
+  return { x: position.x + 1, y: position.y + 1 };
+};
+
+HTMLActuator.prototype.positionClass = function (position) {
+  position = this.normalizePosition(position);
+  return "tile-position-" + position.x + "-" + position.y;
+};
+
+HTMLActuator.prototype.updateScore = function (score) {
+  this.clearContainer(this.scoreContainer);
+
+  var difference = score - this.score;
+  this.score = score;
+
+  this.scoreContainer.textContent = this.score;
+
+  if (difference > 0) {
+    var addition = document.createElement("div");
+    addition.classList.add("score-addition");
+    addition.textContent = "+" + difference;
+
+    this.scoreContainer.appendChild(addition);
+  }
+};
+
+HTMLActuator.prototype.message = function (won) {
+  var type    = won ? "game-won" : "game-over";
+  var message = won ? "You win!" : "Game over!"
+
+  this.messageContainer.classList.add(type);
+  this.messageContainer.getElementsByTagName("p")[0].textContent = message;
+};
+
+HTMLActuator.prototype.clearMessage = function () {
+  this.messageContainer.classList.remove("game-won", "game-over");
+};
+

--- /dev/null
+++ b/js/keyboard_input_manager.js
@@ -1,1 +1,56 @@
+function KeyboardInputManager() {
+  this.events = {};
 
+  this.listen();
+}
+
+KeyboardInputManager.prototype.on = function (event, callback) {
+  if (!this.events[event]) {
+    this.events[event] = [];
+  }
+  this.events[event].push(callback);
+};
+
+KeyboardInputManager.prototype.emit = function (event, data) {
+  var callbacks = this.events[event];
+  if (callbacks) {
+    callbacks.forEach(function (callback) {
+      callback(data);
+    });
+  }
+};
+
+KeyboardInputManager.prototype.listen = function () {
+  var self = this;
+
+  var map = {
+    38: 0, // Up
+    39: 1, // Right
+    40: 2, // Down
+    37: 3  // Left
+  };
+
+  document.addEventListener("keydown", function (event) {
+    var modifiers = event.altKey && event.ctrlKey && event.metaKey &&
+                    event.shiftKey;
+    var mapped    = map[event.which];
+
+    if (!modifiers) {
+      if (mapped !== undefined) {
+        event.preventDefault();
+        self.emit("move", mapped);
+      }
+
+      if (event.which === 32) self.restart.bind(self)(event);
+    }
+  });
+
+  var retry = document.getElementsByClassName("retry-button")[0];
+  retry.addEventListener("click", this.restart.bind(this));
+};
+
+KeyboardInputManager.prototype.restart = function (event) {
+  event.preventDefault();
+  this.emit("restart");
+};
+

file:b/js/tile.js (new)
--- /dev/null
+++ b/js/tile.js
@@ -1,1 +1,18 @@
+function Tile(position, value) {
+  this.x                = position.x;
+  this.y                = position.y;
+  this.value            = value || 2;
 
+  this.previousPosition = null;
+  this.mergedFrom       = null; // Tracks tiles that merged together
+}
+
+Tile.prototype.savePosition = function () {
+  this.previousPosition = { x: this.x, y: this.y };
+};
+
+Tile.prototype.updatePosition = function (position) {
+  this.x = position.x;
+  this.y = position.y;
+};
+

--- a/style/helpers.scss
+++ b/style/helpers.scss
@@ -31,3 +31,26 @@
   -moz-transition-property: $args;
 }
 
+// Keyframe animations
+@mixin keyframes($animation-name) {
+  @-webkit-keyframes $animation-name {
+    @content;
+  }
+  @-moz-keyframes $animation-name {
+    @content;
+  }
+  @keyframes $animation-name {
+    @content;
+  }
+}
+
+@mixin animation($str) {
+  -webkit-animation: #{$str};
+  -moz-animation: #{$str};
+}
+
+@mixin animation-fill-mode($str) {
+  -webkit-animation-fill-mode: #{$str};
+  -moz-animation-fill-mode: #{$str};
+}
+

--- a/style/main.css
+++ b/style/main.css
@@ -4,22 +4,135 @@
   padding: 0;
   background: #faf8ef;
   color: #776e65;
-  font-family: "Clear Sans", "Helvetica Neue", Arial, sans-serif; }
+  font-family: "Clear Sans", "Helvetica Neue", Arial, sans-serif;
+  font-size: 18px; }
 
 body {
   margin: 80px 0; }
 
-h1 {
+.heading:after {
+  content: "";
+  display: block;
+  clear: both; }
+
+h1.title {
   font-size: 80px;
   font-weight: bold;
-  margin: 0; }
+  margin: 0;
+  display: block;
+  float: left; }
+
+@-webkit-keyframes move-up {
+  0% {
+    top: 25px;
+    opacity: 1; }
+
+  100% {
+    top: -50px;
+    opacity: 0; } }
+
+@-moz-keyframes move-up {
+  0% {
+    top: 25px;
+    opacity: 1; }
+
+  100% {
+    top: -50px;
+    opacity: 0; } }
+
+@keyframes move-up {
+  0% {
+    top: 25px;
+    opacity: 1; }
+
+  100% {
+    top: -50px;
+    opacity: 0; } }
+
+.score-container {
+  position: relative;
+  float: right;
+  background: #bbada0;
+  padding: 15px 25px;
+  font-size: 25px;
+  height: 25px;
+  line-height: 47px;
+  font-weight: bold;
+  border-radius: 3px;
+  color: white;
+  margin-top: 8px; }
+  .score-container:after {
+    position: absolute;
+    width: 100%;
+    top: 10px;
+    left: 0;
+    content: "Score";
+    text-transform: uppercase;
+    font-size: 13px;
+    line-height: 13px;
+    text-align: center;
+    color: #eee4da; }
+  .score-container .score-addition {
+    position: absolute;
+    right: 30px;
+    color: red;
+    font-size: 25px;
+    line-height: 25px;
+    font-weight: bold;
+    color: rgba(119, 110, 101, 0.9);
+    z-index: 100;
+    -webkit-animation: move-up 600ms ease-in;
+    -moz-animation: move-up 600ms ease-in;
+    -webkit-animation-fill-mode: both;
+    -moz-animation-fill-mode: both; }
+
+p {
+  margin-top: 0;
+  margin-bottom: 10px;
+  line-height: 1.65; }
+
+a {
+  color: #776e65;
+  font-weight: bold;
+  text-decoration: underline;
+  cursor: pointer; }
+
+strong.important {
+  text-transform: uppercase; }
+
+hr {
+  border: none;
+  border-bottom: 1px solid #d8d4d0;
+  margin-top: 20px;
+  margin-bottom: 30px; }
 
 .container {
   width: 500px;
   margin: 0 auto; }
 
+@-webkit-keyframes fade-in {
+  0% {
+    opacity: 0; }
+
+  100% {
+    opacity: 1; } }
+
+@-moz-keyframes fade-in {
+  0% {
+    opacity: 0; }
+
+  100% {
+    opacity: 1; } }
+
+@keyframes fade-in {
+  0% {
+    opacity: 0; }
+
+  100% {
+    opacity: 1; } }
+
 .game-container {
-  margin-top: 50px;
+  margin-top: 40px;
   position: relative;
   padding: 15px;
   cursor: default;
@@ -30,7 +143,47 @@
   border-radius: 6px;
   width: 500px;
   height: 500px;
+  -webkit-box-sizing: border-box;
+  -moz-box-sizing: border-box;
   box-sizing: border-box; }
+  .game-container .game-message {
+    display: none;
+    position: absolute;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    background: rgba(238, 228, 218, 0.5);
+    z-index: 100;
+    text-align: center;
+    -webkit-animation: fade-in 800ms ease 1200ms;
+    -moz-animation: fade-in 800ms ease 1200ms;
+    -webkit-animation-fill-mode: both;
+    -moz-animation-fill-mode: both; }
+    .game-container .game-message p {
+      font-size: 60px;
+      font-weight: bold;
+      height: 60px;
+      line-height: 60px;
+      margin-top: 222px; }
+    .game-container .game-message .lower {
+      display: block;
+      margin-top: 59px; }
+    .game-container .game-message a {
+      display: inline-block;
+      background: #8f7a66;
+      border-radius: 3px;
+      padding: 0 20px;
+      text-decoration: none;
+      color: #f9f6f2;
+      height: 40px;
+      line-height: 42px;
+      margin-left: 9px; }
+    .game-container .game-message.game-won {
+      background: rgba(237, 194, 46, 0.5);
+      color: #f9f6f2; }
+    .game-container .game-message.game-won, .game-container .game-message.game-over {
+      display: block; }
 
 .grid-container {
   position: absolute;
@@ -69,8 +222,9 @@
   line-height: 116.25px;
   font-size: 55px;
   font-weight: bold;
-  -webkit-transition: 200ms ease;
-  -moz-transition: 200ms ease;
+  z-index: 10;
+  -webkit-transition: 100ms ease-in-out;
+  -moz-transition: 100ms ease-in-out;
   -webkit-transition-property: top, left;
   -moz-transition-property: top, left; }
   .tile.tile-position-1-1 {
@@ -80,63 +234,63 @@
   .tile.tile-position-1-2 {
     position: absolute;
     left: 0px;
-    top: 121.25px; }
+    top: 121px; }
   .tile.tile-position-1-3 {
     position: absolute;
     left: 0px;
-    top: 242.5px; }
+    top: 243px; }
   .tile.tile-position-1-4 {
     position: absolute;
     left: 0px;
-    top: 363.75px; }
+    top: 364px; }
   .tile.tile-position-2-1 {
     position: absolute;
-    left: 121.25px;
+    left: 121px;
     top: 0px; }
   .tile.tile-position-2-2 {
     position: absolute;
-    left: 121.25px;
-    top: 121.25px; }
+    left: 121px;
+    top: 121px; }
   .tile.tile-position-2-3 {
     position: absolute;
-    left: 121.25px;
-    top: 242.5px; }
+    left: 121px;
+    top: 243px; }
   .tile.tile-position-2-4 {
     position: absolute;
-    left: 121.25px;
-    top: 363.75px; }
+    left: 121px;
+    top: 364px; }
   .tile.tile-position-3-1 {
     position: absolute;
-    left: 242.5px;
+    left: 243px;
     top: 0px; }
   .tile.tile-position-3-2 {
     position: absolute;
-    left: 242.5px;
-    top: 121.25px; }
+    left: 243px;
+    top: 121px; }
   .tile.tile-position-3-3 {
     position: absolute;
-    left: 242.5px;
-    top: 242.5px; }
+    left: 243px;
+    top: 243px; }
   .tile.tile-position-3-4 {
     position: absolute;
-    left: 242.5px;
-    top: 363.75px; }
+    left: 243px;
+    top: 364px; }
   .tile.tile-position-4-1 {
     position: absolute;
-    left: 363.75px;
+    left: 364px;
     top: 0px; }
   .tile.tile-position-4-2 {
     position: absolute;
-    left: 363.75px;
-    top: 121.25px; }
+    left: 364px;
+    top: 121px; }
   .tile.tile-position-4-3 {
     position: absolute;
-    left: 363.75px;
-    top: 242.5px; }
+    left: 364px;
+    top: 243px; }
   .tile.tile-position-4-4 {
     position: absolute;
-    left: 363.75px;
-    top: 363.75px; }
+    left: 364px;
+    top: 364px; }
   .tile.tile-2 {
     background: #eee4da;
     box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0), inset 0 0 0 1px rgba(255, 255, 255, 0); }
@@ -144,39 +298,131 @@
     background: #ede0c8;
     box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0), inset 0 0 0 1px rgba(255, 255, 255, 0); }
   .tile.tile-8 {
-    background: #edddb7;
-    box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0), inset 0 0 0 1px rgba(255, 255, 255, 0); }
+    color: #f9f6f2;
+    background: #f2b179; }
   .tile.tile-16 {
-    background: #edd9a6;
-    box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0), inset 0 0 0 1px rgba(255, 255, 255, 0); }
+    color: #f9f6f2;
+    background: #f59563; }
   .tile.tile-32 {
-    background: #edd695;
-    box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0.07937), inset 0 0 0 1px rgba(255, 255, 255, 0.04762); }
+    color: #f9f6f2;
+    background: #f67c5f; }
   .tile.tile-64 {
-    background: #edd384;
-    box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0.15873), inset 0 0 0 1px rgba(255, 255, 255, 0.09524); }
+    color: #f9f6f2;
+    background: #f65e3b; }
   .tile.tile-128 {
+    color: #f9f6f2;
     background: #edcf72;
     box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0.2381), inset 0 0 0 1px rgba(255, 255, 255, 0.14286);
     font-size: 45px; }
   .tile.tile-256 {
+    color: #f9f6f2;
     background: #edcc61;
     box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0.31746), inset 0 0 0 1px rgba(255, 255, 255, 0.19048);
-    color: #ede9e5;
     font-size: 45px; }
   .tile.tile-512 {
+    color: #f9f6f2;
     background: #edc850;
     box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0.39683), inset 0 0 0 1px rgba(255, 255, 255, 0.2381);
-    color: #f9f6f2;
     font-size: 45px; }
   .tile.tile-1024 {
+    color: #f9f6f2;
     background: #edc53f;
     box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0.47619), inset 0 0 0 1px rgba(255, 255, 255, 0.28571);
-    color: #f9f6f2;
     font-size: 35px; }
   .tile.tile-2048 {
+    color: #f9f6f2;
     background: #edc22e;
     box-shadow: 0 0 30px 10px rgba(243, 215, 116, 0.55556), inset 0 0 0 1px rgba(255, 255, 255, 0.33333);
-    color: #f9f6f2;
     font-size: 35px; }
 
+@-webkit-keyframes appear {
+  0% {
+    opacity: 0;
+    -webkit-transform: scale(0);
+    -moz-transform: scale(0); }
+
+  100% {
+    opacity: 1;
+    -webkit-transform: scale(1);
+    -moz-transform: scale(1); } }
+
+@-moz-keyframes appear {
+  0% {
+    opacity: 0;
+    -webkit-transform: scale(0);
+    -moz-transform: scale(0); }
+
+  100% {
+    opacity: 1;
+    -webkit-transform: scale(1);
+    -moz-transform: scale(1); } }
+
+@keyframes appear {
+  0% {
+    opacity: 0;
+    -webkit-transform: scale(0);
+    -moz-transform: scale(0); }
+
+  100% {
+    opacity: 1;
+    -webkit-transform: scale(1);
+    -moz-transform: scale(1); } }
+
+.tile-new {
+  -webkit-animation: appear 200ms ease 100ms;
+  -moz-animation: appear 200ms ease 100ms;
+  -webkit-animation-fill-mode: both;
+  -moz-animation-fill-mode: both; }
+
+@-webkit-keyframes pop {
+  0% {
+    -webkit-transform: scale(0);
+    -moz-transform: scale(0); }
+
+  50% {
+    -webkit-transform: scale(1.2);
+    -moz-transform: scale(1.2); }
+
+  100% {
+    -webkit-transform: scale(1);
+    -moz-transform: scale(1); } }
+
+@-moz-keyframes pop {
+  0% {
+    -webkit-transform: scale(0);
+    -moz-transform: scale(0); }
+
+  50% {
+    -webkit-transform: scale(1.2);
+    -moz-transform: scale(1.2); }
+
+  100% {
+    -webkit-transform: scale(1);
+    -moz-transform: scale(1); } }
+
+@keyframes pop {
+  0% {
+    -webkit-transform: scale(0);
+    -moz-transform: scale(0); }
+
+  50% {
+    -webkit-transform: scale(1.2);
+    -moz-transform: scale(1.2); }
+
+  100% {
+    -webkit-transform: scale(1);
+    -moz-transform: scale(1); } }
+
+.tile-merged {
+  z-index: 20;
+  -webkit-animation: pop 200ms ease 100ms;
+  -moz-animation: pop 200ms ease 100ms;
+  -webkit-animation-fill-mode: both;
+  -moz-animation-fill-mode: both; }
+
+.game-intro {
+  margin-bottom: 0; }
+
+.game-explanation {
+  margin-top: 50px; }
+

--- a/style/main.scss
+++ b/style/main.scss
@@ -8,12 +8,16 @@
 $tile-border-radius: 3px;
 
 $text-color: #776E65;
-$gold-text-color: #f9f6f2;
+$bright-text-color: #f9f6f2;
 
 $tile-color: #eee4da;
 $tile-gold-color: #edc22e;
 $tile-gold-glow-color: lighten($tile-gold-color, 15%);
 
+$game-container-background: #bbada0;
+
+$transition-speed: 100ms;
+
 html, body {
   margin: 0;
   padding: 0;
@@ -21,16 +25,105 @@
   background: #faf8ef;
   color: $text-color;
   font-family: "Clear Sans", "Helvetica Neue", Arial, sans-serif;
+  font-size: 18px;
 }
 
 body {
   margin: 80px 0;
 }
 
-h1 {
+.heading:after {
+  content: "";
+  display: block;
+  clear: both;
+}
+
+h1.title {
   font-size: 80px;
   font-weight: bold;
   margin: 0;
+  display: block;
+  float: left;
+}
+
+@include keyframes(move-up) {
+  0% {
+    top: 25px;
+    opacity: 1;
+  }
+
+  100% {
+    top: -50px;
+    opacity: 0;
+  }
+}
+
+.score-container {
+  $height: 25px;
+
+  position: relative;
+  float: right;
+  background: $game-container-background;
+  padding: 15px 25px;
+  font-size: $height;
+  height: $height;
+  line-height: $height + 22px;
+  font-weight: bold;
+  border-radius: 3px;
+  color: white;
+  margin-top: 8px;
+
+  &:after {
+    position: absolute;
+    width: 100%;
+    top: 10px;
+    left: 0;
+    content: "Score";
+    text-transform: uppercase;
+    font-size: 13px;
+    line-height: 13px;
+    text-align: center;
+    color: $tile-color;
+  }
+
+  .score-addition {
+    position: absolute;
+    right: 30px;
+    color: red;
+    font-size: $height;
+    line-height: $height;
+    font-weight: bold;
+    color: rgba($text-color, .9);
+    z-index: 100;
+    @include animation(move-up 600ms ease-in);
+    @include animation-fill-mode(both);
+  }
+}
+
+p {
+  margin-top: 0;
+  margin-bottom: 10px;
+  line-height: 1.65;
+}
+
+a {
+  color: $text-color;
+  font-weight: bold;
+  text-decoration: underline;
+  cursor: pointer;
+}
+
+strong {
+  &.important {
+    text-transform: uppercase;
+  }
+}
+
+hr {
+  border: none;
+  border-bottom: 1px solid lighten($text-color, 40%);
+  margin-top: 20px;
+  margin-bottom: 30px;
 }
 
 .container {
@@ -38,8 +131,18 @@
   margin: 0 auto;
 }
 
+@include keyframes(fade-in) {
+  0% {
+    opacity: 0;
+  }
+
+  100% {
+    opacity: 1;
+  }
+}
+
 .game-container {
-  margin-top: 50px;
+  margin-top: 40px;
   position: relative;
   padding: $grid-spacing;
 
@@ -48,11 +151,67 @@
   -webkit-user-select: none;
   -moz-user-select: none;
 
-  background: #bbada0;
+  background: $game-container-background;
   border-radius: $tile-border-radius * 2;
   width: $field-width;
   height: $field-width;
+  -webkit-box-sizing: border-box;
+  -moz-box-sizing: border-box;
   box-sizing: border-box;
+
+  .game-message {
+    display: none;
+
+    position: absolute;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    background: rgba($tile-color, .5);
+    z-index: 100;
+
+    text-align: center;
+
+    p {
+      font-size: 60px;
+      font-weight: bold;
+      height: 60px;
+      line-height: 60px;
+      margin-top: 222px;
+      // height: $field-width;
+      // line-height: $field-width;
+    }
+
+    .lower {
+      display: block;
+      margin-top: 59px;
+    }
+
+    a {
+      display: inline-block;
+      background: darken($game-container-background, 20%);
+      border-radius: 3px;
+      padding: 0 20px;
+      text-decoration: none;
+      color: $bright-text-color;
+      height: 40px;
+      line-height: 42px;
+      margin-left: 9px;
+      // margin-top: 59px;
+    }
+
+    @include animation(fade-in 800ms ease $transition-speed * 12);
+    @include animation-fill-mode(both);
+
+    &.game-won {
+      background: rgba($tile-gold-color, .5);
+      color: $bright-text-color;
+    }
+
+    &.game-won, &.game-over {
+      display: block;
+    }
+  }
 }
 
 .grid-container {
@@ -105,16 +264,18 @@
   line-height: $tile-size + 10px;
   font-size: 55px;
   font-weight: bold;
-
-  @include transition(200ms ease);
+  z-index: 10;
+
+  @include transition($transition-speed ease-in-out);
   @include transition-property(top, left);
 
+  // Build position classes
   @for $x from 1 through $grid-row-cells {
     @for $y from 1 through $grid-row-cells {
       &.tile-position-#{$x}-#{$y} {
         position: absolute;
-        left: ($tile-size + $grid-spacing) * ($x - 1);
-        top: ($tile-size + $grid-spacing) * ($y - 1);
+        left: round(($tile-size + $grid-spacing) * ($x - 1));
+        top: round(($tile-size + $grid-spacing) * ($y - 1));
       }
     }
   }
@@ -123,25 +284,53 @@
   $exponent: 1;
   $limit: 11;
 
+  // Colors for all 11 states, false = no special color
+  $special-colors: false false, // 2
+                   false false, // 4
+                   #f78e48 true, // 8
+                   #fc5e2e true, // 16
+                   #ff3333 true, // 32
+                   #ff0000 true, // 64
+                   false true, // 128
+                   false true, // 256
+                   false true, // 512
+                   false true, // 1024
+                   false true; // 2048
+
+  // Build tile colors
   @while $exponent <= $limit {
     $power: pow($base, $exponent);
 
-    $gold-percent: ($exponent - 1) / ($limit - 1) * 100;
-
-    $gold-text-percent: min($exponent + 2, $limit) / ($limit) * 100;
-
-    $glow-opacity: max($exponent - 4, 0) / ($limit - 4);
-
     &.tile-#{$power} {
-      background: mix($tile-gold-color, $tile-color, $gold-percent);
-
-      box-shadow: 0 0 30px 10px rgba($tile-gold-glow-color, $glow-opacity / 1.8),
-                  inset 0 0 0 1px rgba(white, $glow-opacity / 3);
-
-      @if $exponent >= 8 {
-        color: mix($gold-text-color, $text-color, $gold-text-percent);
-      }
-
+      // Calculate base background color
+      $gold-percent: ($exponent - 1) / ($limit - 1) * 100;
+      $mixed-background: mix($tile-gold-color, $tile-color, $gold-percent);
+
+      $nth-color: nth($special-colors, $exponent);
+
+      $special-background: nth($nth-color, 1);
+      $bright-color: nth($nth-color, 2);
+
+      @if $special-background {
+        $mixed-background: mix($special-background, $mixed-background, 55%);
+      }
+
+      @if $bright-color {
+        color: $bright-text-color;
+      }
+
+      // Set background
+      background: $mixed-background;
+
+      // Add glow
+      $glow-opacity: max($exponent - 4, 0) / ($limit - 4);
+
+      @if not $special-background {
+        box-shadow: 0 0 30px 10px rgba($tile-gold-glow-color, $glow-opacity / 1.8),
+                    inset 0 0 0 1px rgba(white, $glow-opacity / 3);
+      }
+
+      // Adjust font size for bigger numbers
       @if $power >= 100 and $power < 1000 {
         font-size: 45px;
       } @else if $power >= 1000 {
@@ -153,5 +342,53 @@
   }
 }
 
-
-
+@include keyframes(appear) {
+  0% {
+    opacity: 0;
+    -webkit-transform: scale(0);
+    -moz-transform: scale(0);
+  }
+
+  100% {
+    opacity: 1;
+    -webkit-transform: scale(1);
+    -moz-transform: scale(1);
+  }
+}
+
+.tile-new {
+  @include animation(appear 200ms ease $transition-speed);
+  @include animation-fill-mode(both);
+}
+
+@include keyframes(pop) {
+  0% {
+    -webkit-transform: scale(0);
+    -moz-transform: scale(0);
+  }
+
+  50% {
+    -webkit-transform: scale(1.2);
+    -moz-transform: scale(1.2);
+  }
+
+  100% {
+    -webkit-transform: scale(1);
+    -moz-transform: scale(1);
+  }
+}
+
+.tile-merged {
+  z-index: 20;
+  @include animation(pop 200ms ease $transition-speed);
+  @include animation-fill-mode(both);
+}
+
+.game-intro {
+  margin-bottom: 0;
+}
+
+.game-explanation {
+  margin-top: 50px;
+}
+

comments