.flex{
  display: -webkit-flex;
  display: -moz-flex;
  display: -ms-flex;
  display: -o-flex;
  display: flex;

  -webkit-flex-direction: row;
  -moz-flex-direction: row;
  -ms-flex-direction: row;
  -o-direction: row;
  flex-direction: row;

  -webkit-flex-pack:center;
  -moz-flex-pack:center;
  -ms-flex-pack:center;
  -o-flex-pack:center;
  flex-pack:center;

}
.flex > div{
  -webkit-flex: 1 1 auto;
  -moz-flex: 1 1 auto;
  -ms-flex: 1 1 auto;
  -o-flex: 1 1 auto;
  flex: 1 1 auto;

  -webkit-flex-align: center;
  -moz-flex-align: center;
  -ms-flex-align: center;
  -o-flex-align: center;
  flex-align: center;

  -webkit-transition: width 0.2s ease-out;
  transition: width 0.2s ease-out;
}