.container, .container-lg, .container-md, .container-sm, .container-xl {
  width: 100%;
  padding-right: 15px;
  padding-left: 15px;
  margin-right: auto;
  margin-left: auto;
}

body {
  font-family: Arial, Helvetica, sans-serif;
}

.flip-card {
  background-color: transparent;
  width: 300px;
  height: 300px;
  perspective: 1000px;
}

.flip-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: transform 0.6s;
  transform-style: preserve-3d;
  box-shadow: 0 4px 8px 0 rgba(0,0,0,0.2);
}

.flip-card:hover .flip-card-inner {
  transform: rotateY(180deg);
}

.flip-card-front {
  background-color: #bbb;
  color: black;
  position: absolute;
  width: 100%;
  height: 100%;
  /*-webkit-backface-visibility: hidden;*/
  backface-visibility: hidden;
}

.flip-card-back {
  background-color: #2980b9;
  color: white;
  transform: rotateY(180deg);
  position: absolute;
  width: 100%;
  height: 100%;
}