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