我正在尝试在FireFox中为输入占位符放置填充，到目前为止没有运气。我试过在FireFox中使用填充，文本缩进和无效工作。我的代码如下。非常感谢任何帮助。
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<link href="style.css" type="text/css" rel="stylesheet" />
</head>
<html>
<body>
<div id='contact_form'>
<input type='text' name='subject' placeholder='Subject' id='Subject' class='contactForm_keys' title='Subject' />
</div>
</body>
</html>
CSS：
#Subject{
margin-left: 43px;
margin-bottom: -8px;
width: 605px;
height: 40px;
}
#Subject:focus, #Subject:hover{
border: 1px solid black;
background: white;
}
/*input placeholder styling*/
input::-webkit-input-placeholder{font-size:14px; font-family: Arial, Helvetica, Sans-serif; color:#c46457; padding-left: 15px;}
input:-moz-placeholder{font-size:14px; font-family: Arial, Helvetica, Sans-serif; color:#c46457; line-height: normal; padding: 0 10px 0 29px;}
input::-moz-placeholder{font-size:14px; font-family: Arial, Helvetica, Sans-serif; color:#c46457; line-height: normal; padding: 0 10px 0 29px;}
#contact_frm input:-ms-input-placeholder{font-size:14px; font-family: Arial, Helvetica, Sans-serif; color:#c46457; padding-left: 15px;}