404倒计时返回上一页

【前言】

      介绍个简单404页面自动跳页方法，这里我直接把源码复制过来。

      原理很简单，js控制判断。这里我加了css3的文本阴影特效。看上去更加绚丽

【主体】

 <style type="text/css">
        body {
            background-color: #ECECEC;
            font-family: 'Open Sans', sans-serif;
            font-size: 14px;
            color: #3c3c3c;
        }
        .demo{width: 600px;margin: 60px auto 0;}
        .demo p:first-child {
            text-align: center;
            font-family: cursive;
            font-size: 150px;
            font-weight: bold;
            line-height: 100px;
            letter-spacing: 5px;
            color: #fff;
        }

        .demo p:first-child span {
            cursor: pointer;
            text-shadow: 0px 0px 2px #686868,
            0px 1px 1px #ddd,
            0px 2px 1px #d6d6d6,
            0px 3px 1px #ccc,
            0px 4px 1px #c5c5c5,
            0px 5px 1px #c1c1c1,
            0px 6px 1px #bbb,
            0px 7px 1px #777,
            0px 8px 3px rgba(100, 100, 100, 0.4),
            0px 9px 5px rgba(100, 100, 100, 0.1),
            0px 10px 7px rgba(100, 100, 100, 0.15),
            0px 11px 9px rgba(100, 100, 100, 0.2),
            0px 12px 11px rgba(100, 100, 100, 0.25),
            0px 13px 15px rgba(100, 100, 100, 0.3);
            -webkit-transition: all .1s linear;
            transition: all .1s linear;
        }

        .demo p:first-child span:hover {
            text-shadow: 0px 0px 2px #686868,
            0px 1px 1px #fff,
            0px 2px 1px #fff,
            0px 3px 1px #fff,
            0px 4px 1px #fff,
            0px 5px 1px #fff,
            0px 6px 1px #fff,
            0px 7px 1px #777,
            0px 8px 3px #fff,
            0px 9px 5px #fff,
            0px 10px 7px #fff,
            0px 11px 9px #fff,
            0px 12px 11px #fff,
            0px 13px 15px #fff;
            -webkit-transition: all .1s linear;
            transition: all .1s linear;
        }

        .demo p:not(:first-child) {
            text-align: center;
            color: #666;
            font-family: cursive;
            font-size: 20px;
            text-shadow: 0 1px 0 #fff;
            letter-spacing: 1px;
            line-height: 2em;
            margin-top: -50px;
        }
        #mes{
            color: #13c5f8;
        }
    </style>

<div class="demo">
    <p><span>4</span><span>0</span><span>4</span></p>
    <p>该页面暂未开放或不存在(´･ω･`)，并在<span id="mes">3</span>秒后自动跳转到上一页</p>
</div>
<script>
// 定时跳转setTimeout("window.history.back(-1)", 3000);
</script>
<script language="javascript" type="text/javascript">
    var i = 3;
    var intervalid;
    intervalid = setInterval("fun()", 1000);
    function fun() {
        if (i == 0) {
            window.history.back(-1);
            clearInterval(intervalid);
        }
        document.getElementById("mes").innerHTML = i;
        i--;
    }
</script>

</body>

.