求助为什么我不能编辑那两个button
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style>
*{margin:0;padding:0;}
.container{
width:220px;
height:350px;
background:#ebf2fa;
}
.form_m{
padding:15px;
}
.input_text{
display:block;
width:180px;
height:28px;
margin-top:12px;
border-radius:4px;/*圆角矩形*/
text-indent:20px;/*文字缩进，需块元素或内联块元素*/
}
p{
margin-top:10px;
height:50px;
font-size:13px;
}
p label{
vertical-align: top;
}
p a{
text-decoration:none;
float:right;
}
}
.btn{
width:200px;
height:20px;
background:url(http://img1.sycdn.imooc.com//539a972b00013e9102280177.jpg)
}
</style>
</head>
<body>
<div class="container">
<form class="form_m">
<input class="input_text" placeholder="邮箱/手机号/用户名" type="text"/>
<input class="input_text" placeholder ="请输入密码"type="password"/>
<p>
<input class="checkbox" type="checkbox" id="1"/>
<label for="1">下次自动登陆</label>
<a href="javascript:;">忘记密码?</a>
</p>
<input class="btn" type="submit" value="登陆"/>
<hr/>
<input class="btn" type="button" value="注册"/>
</form>
</div>
</body>
</html>怎么改都没用
