使用具有梯度背景的CSS 3过渡
rgba()
#container div a { -webkit-transition: background 0.2s linear; -moz-transition: background 0.2s linear; -o-transition: background 0.2s linear; transition: background 0.2s linear; position: absolute; width: 200px; height: 150px; border: 1px #000 solid; margin: 30px; z-index: 2}#container div a:hover { background: -webkit-gradient(radial, 100 75, 100, 100 75, 0, from(rgba(0, 0, 0, .7)), to(rgba(0, 0, 0, .4)))}