html,body {width: 100%; height: 100%; margin:0; padding:0;}

body {background: -webkit-linear-gradient(#000000, #333333); /* Safari 5.1 - 6.0 */
  background: -o-linear-gradient(#000000, #333333); /* Opera 11.1 - 12.0 */
  background: -moz-linear-gradient(#000000, #333333); /* Firefox 3.6 - 15 */
  background: linear-gradient(#000000, #333333); /* 标准的语法 */
  width: 100%;
  height: 100%;
  /* padding-top: 30%; */
  position: relative;
  
  
}
a,span {color: white; font-size: 12px; text-decoration:none;}



img {margin: auto; display: block;}

div {text-align: center; position: absolute;}

.foot {position: absolute; bottom: 20px; width: 100%; text-align: center; border-top: 1px solid #959595; color: #959595;}