效果图：在菜鸟教程在线编辑的

 上代码：

<div id="grad1"></div>

、、、

<style>
#grad1 {
	height: 200px;
	width:150px;
    background-image: linear-gradient(to top, rgba(	135,206,250,0), rgba(135,206,250,0.6) 50%,rgba(	135,206,250,0));
}
</style>