背景渐变 css3 background
background: -webkit-linear-gradient(left, #730ed6, #561ff6); background: -webkit-gradient(linear,0% 100%, 100% 0% , from(#730ed6), to(#561ff6)); background:-webkit-linear-gradient(0deg, #730ed6, #561ff6);
点击了解详情:http://www.w3cplus.com/css3/new-css3-linear-gradient.html