background-image: linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480), linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480);
渐变的参数究竟是怎么回事?
http://www.runoob.com/css3/css3-gradients.html 这里面有很全的由浅入深的讲解