里面最关键的地方使用了css3 animation的delay属性以及
贝塞尔曲线（cubic-bezier）的过渡效果，如下所示
span[class*=”l-“] { height: 8px; width: 8px; background: #fff; display: inline-block; margin: 12px 2px; border-radius: 100%; -webkit-border-radius: 100%; -moz-border-radius: 100%; -webkit-animation: loader 4s infinite; -webkit-animation-timing-function: cubic-bezier(0.030, 0.615, 0.995, 0.415); -webkit-animation-fill-mode: both; -moz-animation: loader 4s infinite; -moz-animation-timing-function: cubic-bezier(0.030, 0.615, 0.995, 0.415); -moz-animation-fill-mode: both; -ms-animation: loader 4s infinite; -ms-animation-timing-function: cubic-bezier(0.030, 0.615, 0.995, 0.415); -ms-animation-fill-mode: both; animation: loader 4s infinite; animation-timing-function: cubic-bezier(0.030, 0.615, 0.995, 0.415); animation-fill-mode: both;}span.l-1 {-webkit-animation-delay: 1s;animation-delay: 1s;-ms-animation-delay: 1s;-moz-animation-delay: 1s;}span.l-2 {-webkit-animation-delay: 0.8s;animation-delay: 0.8s;-ms-animation-delay: 0.8s;-moz-animation-delay: 0.8s;}span.l-3 {-webkit-animation-delay: 0.6s;animation-delay: 0.6s;-ms-animation-delay: 0.6s;-moz-animation-delay: 0.6s;}span.l-4 {-webkit-animation-delay: 0.4s;animation-delay: 0.4s;-ms-animation-delay: 0.4s;-moz-animation-delay: 0.4s;}span.l-5 {-webkit-animation-delay: 0.2s;animation-delay: 0.2s;-ms-animation-delay: 0.2s;-moz-animation-delay: 0.2s;}span.l-6 {-webkit-animation-delay: 0;animation-delay: 0;-ms-animation-delay: 0;-moz-animation-delay: 0;}
在线演示源码下载
