效果图：
代码如下：
background-image: -webkit-gradient(linear,left top, left bottom,from(rgba(255,255,255,0)),color-stop(70%, #fff));
background-image: linear-gradient(-180deg,rgba(255,255,255,0) 0%,#fff 70%);
效果图：
代码如下：
background-image: -webkit-gradient(linear,left top,right top,from(rgba(255,255,255,0)),color-stop(47%,#fff));
background-image: linear-gradient(90deg,rgba(255,255,255,0) 0,#fff 47%);
原文：https://www.cnblogs.com/hool/p/11363724.html