使用grid-template-columns属性定义CSS Grid Layout中的列数。
您可以尝试运行以下代码来设置列数。在这里，设置了三列网格：
<!DOCTYPE html>
<html>
<head>
<style>
.container {
display: grid;
background-color: yellow;
grid-template-columns: auto auto auto;
padding: 20px;
grid-gap: 20px;
}
.container > div {
background-color: blue;
border: 2px solid gray;
padding: 35px;
font-size: 30px;
text-align: center;
}
</style>
</head>
<body>
<h1>Game Board</h1>
<div class = "container">
<div class = "ele1">1</div>
<div class = "ele2">2</div>
<div class = "ele3">3</div>
<div class = "ele4">4</div>
<div class = "ele5">5</div>
<div class = "ele6">6</div>
</div>
</body>
</html>