代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>子选择器</title>
<style>
.nav>a{
color: red;
}
</style>
</head>
<body>
<div class="nav">
<a href="#">这是儿子</a>
<p>
<a href="#">这是孙子</a>
</p>
</div>
</body>
</html>运行效果：