CSS

.container {
  position: relative;
  display:table;
  background: red;
  width:100%;
  height: 100%; /* auto is default,you can have ur height here */
}
.container-wrapper {
  display: table-cell;
  margin:auto;
  text-align:center;
  font-size:0;
  width:90%;
  height:90%;
  vertical-align:middle;
}
.card {
  display: inline-block;
  height:100px;
  width:100px;
  border: 1px solid #ddd;
  background: #eee;
  margin:10px;
}

DEMO 2 with some height of the container