Step 2

The index.html is mostly boilerplate code. The following piece is responsible for structuring the game board.

<div class="game board">
  <div class="row">
    <div class="cell" id="0"></div>
    <div class="cell" id="1"></div>
    <div class="cell" id="2"></div>
  </div>
  <div class="row">
    <div class="cell" id="3"></div>
    <div class="cell" id="4"></div>
    <div class="cell" id="5"></div>
  </div>
  <div class="row">
    <div class="cell" id="6"></div>
    <div class="cell" id="7"></div>
    <div class="cell" id="8"></div>
  </div>
</div>