static/404.html

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <title>XBMAN| 404 Page not found</title>
  <!-- Tell the browser to be responsive to screen width -->
  <meta content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no" name="viewport">
  <!-- Bootstrap 3.3.6 -->
  <link rel="stylesheet" href="/static/vendor/bootstrap/css/bootstrap.min.css">
    <link rel="icon" href="/static/dist/img/icon.png" mce_href="dist/img/icon.png" type="image/x-icon">
  <style type="text/css">
  	.content {
    min-height: 250px;
    padding: 15px;
    margin-right: auto;
    margin-left: auto;
    padding-left: 15px;
    padding-right: 15px;
    }
    .error-page {
        width: 600px;
        margin: 20px auto 0 auto;
    }
    .error-page>.headline {
        float: left;
        font-size: 100px;
        font-weight: 300;
    }
    .text-yellow {
        color: #f39c12 !important;
    }
    .error-page>.error-content {
        margin-left: 190px;
        display: block;
    }
    .text-yellow {
        color: #f39c12 !important;
    }
    #wenzi{
        font-size: 20px;
    }
  </style>
</head>
<body class="">
  <div>
    <section class="content">
      <div class="error-page">
        <h2 class="headline text-yellow"> 404</h2>

        <div class="error-content" style="margin-top: 90px;">
          <h3><i class="glyphicon glyphicon-warning-sign text-yellow" style="margin-top: 10px;"></i> Oops! Page not found.</h3>

          <p id="wenzi">
            	您访问的页面还在路上.<span style="margin-left:4px;color: red;font-size: 23px;font-weight:bold;" id="xianshi">3</span> 秒后将自动跳回主页，或点击 <a href="/index/">返回主页</a>
          </p>
        </div>
      </div>
    </section>
  </div>
</body>
<script type="text/javascript">
onload=function(){
setInterval(go, 1000);
};
var x=3; //利用了全局变量来执行
function go(){
x--;
if(x>0){
document.getElementById("xianshi").innerHTML=x; //每次设置的x的值都不一样了。
}else{
location.href='/index/';
};
};
</script>
</html>