我想用
null
<body>
<div id="board">
<h1>Tic Tac Toe</h1>
<div class="row">
<div class="top left"></div>
<div class="top middle"></div>
<div class="top right"></div>
</div>
<div class="row">
<div class="middle left"></div>
<div class="middle center"></div>
<div class="middle right"></div>
</div>
<div class="row">
<div class="bottom left"></div>
<div class="bottom middle"></div>
<div class="bottom right"></div>
</div>
</div>
</body>null
我想你可以用like.row:first-child。
