console 命令行工具 X clear
console
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"> 
<title>菜鸟教程(runoob.com)</title> 
</head>
<body>
    <form>
        <label>Name:</label>
        <input name="name" />
        <fieldset>
            <label>Newsletter:</label>
            <input name="newsletter" />
        </fieldset>
    </form>
    <input name="none" />
</body>
<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
    $('form>input').css('background','red')
});
</script>
</html>