box-shadow: 0 5px 5px rgba(255, 255, 255, .7) inset, 0 -5px 5px rgba(255, 255, 255, .7) inset;
-webkit-animation: animate-glow 1s ease-out infinite;
-moz-animation: animate-glow 1s ease-out infinite;
}
@-webkit-keyframes animate-glow {
0% { -webkit-box-shadow: 0 5px 5px rgba(255, 255, 255, .7) inset, 0 -5px 5px rgba(255, 255, 255, .7) inset;}
50% { -webkit-box-shadow: 0 5px 5px rgba(255, 255, 255, .3) inset, 0 -5px 5px rgba(255, 255, 255, .3) inset;}
100% { -webkit-box-shadow: 0 5px 5px rgba(255, 255, 255, .7) inset, 0 -5px 5px rgba(255, 255, 255, .7) inset;}
}
@-moz-keyframes animate-glow {
0% { -moz-box-shadow: 0 5px 5px rgba(255, 255, 255, .7) inset, 0 -5px 5px rgba(255, 255, 255, .7) inset;}
50% { -moz-box-shadow: 0 5px 5px rgba(255, 255, 255, .3) inset, 0 -5px 5px rgba(255, 255, 255, .3) inset;}
100% { -moz-box-shadow: 0 5px 5px rgba(255, 255, 255, .7) inset, 0 -5px 5px rgba(255, 255, 255, .7) inset;}
}
在不支持css3的浏览器下的表现：
demo：http://demo.jb51.net/js/2012/css3-progress-bars/
