#f1_container {
  position: relative;
  margin: 10px auto;
  width: 420px;
  height: 281px;
  z-index: 1;
}
#f1_container {
  perspective: 500;
}
#f1_card {
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: all 1.0s linear;
}
#f1_container:hover #f1_card {
  transform: rotateY(180deg);
  box-shadow: -3px 3px 3px #aaa;
}
.face {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
}
.face.back {
  display: block;
  transform: rotateY(180deg);
  box-sizing: border-box;
  padding: 10px;
  color: white;
  text-align: center;
  background-color: #000441;
}