按照这个直接输入没有达到效果
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>input-placeholder</title>
</head>
<body>
<input type="text" placehoder="请输入用户名">
<input type="password" placehoder="请输入密码">
<input type="email" placehoder="请输入邮箱">
</body>
</html>
