css-flex-vertical-center.txt

/*vertical center*/
.flex-vertical-center {
  display: -webkit-box;
  display: -webkit-flex;
  display: -moz-box;
  display: -moz-flex;
  display: -ms-flexbox;
  display: flex;
  flex-direction: column;
  /* 垂直居中 */
  -webkit-box-pack: center;
  -moz-box-pack: center;
  -ms-flex-align: center;
  /* IE 10 */
  -webkit-justify-content: center;
  -moz-justify-content: center;
  justify-content: center;
  /* IE 11+,Firefox 22+,Chrome 29+,Opera 12.1*/
}