博客园美化：添加顶部浏览进度条

先看效果图：

 顶部进度条会根据浏览页面而变化，话不多说，

代码附上：

    <script>
        (function (w, d) {
            var domDiv = d.createElement('div');

            domDiv.style.cssText = 'position: fixed; top: 0; left: 0; width: 0; height: 3px;' +
                'box-shadow: 0 0 3px #999; background: -webkit-linear-gradient(left, red,orange,yellow,green,blue,indigo,violet );z-index: 999999;-webkit-transition:width .3s linear;'
 
            d.body.appendChild(domDiv);

            var domH = w.innerHeight || d.documentElement.clientHeight || d.body.clientHeight;
      
            w.addEventListener('scroll', function () {
                var divsw = domDiv.style.width = Math.round(pageYOffset / (d.body.offsetHeight - domH) *
                    100) + '%';
            }, false);
        })(window, document);
    </script>