.a{background:-webkit-gradient(linear,0 0,0 100%,from(rgba(0,0,0,0)),to(rgba(0,0,0,1)));background:-webkit-linear-gradient(top,rgba(0,0,0,0),rgba(0,0,0,1));background:-moz-linear-gradient(top,rgba(0,0,0,0),rgba(0,0,0,1));background:-o-linear-gradient(top,rgba(0,0,0,0),rgba(0,0,0,1));background:linear-gradient(top,rgba(0,0,0,0),rgba(0,0,0,1))}.b{background:#FFF;background:rgba(255,255,255,.5)}