一个小而使用的效果，解决在做网站项目时经常碰到的一个问题：页面主体部分的左侧

（或者右侧）需要阴影效果，阴影的效果只在顶部和底部位置体现。但是网页的高度又是变化的！这段代码可以帮你解决这个问题。具体效果看下附件-The use of a small effect, to resolve the problem so often encountered when the project site of a problem: the main part of the left side of the page (or right) the need for the shadow effect, the effect of the shadow only reflect the position at the top and bottom. However, the height of the page is changing! This code can help you solve this problem