.panel-flip {
    float: left;
    width: 50%;
    height: 250px;
    position: relative;

    -webkit-perspective: 600px;
            perspective: 600px;
}

  .panel-flip .front {
    float: none;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1;
    height: inherit;
    width: 100%;
    -webkit-transform: rotateX(0) rotateY(0);
            transform: rotateX(0) rotateY(0);

    -webkit-transform-style: preserve-3d;
            transform-style: preserve-3d;

    -webkit-backface-visibility: hidden;
            backface-visibility: hidden;

    -webkit-transition: all .4s ease-in-out;
            transition: all .4s ease-in-out;
  }
  .panel-flip.flip .front {
    z-index: 1;

    -webkit-transform: rotateY(179deg);
            transform: rotateY(179deg);
  }

  .panel-flip .back {
    overflow-y: auto;
    float: none;
    background-color: #f7f7f7;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 3;
    height: inherit;
    width: 100%;

    -webkit-transform: rotateY(-179deg);
            transform: rotateY(-179deg);

    -webkit-transform-style: preserve-3d;
            transform-style: preserve-3d;

    -webkit-backface-visibility: hidden;
            backface-visibility: hidden;

    /* -- transition is the magic sauce for animation -- */
    -webkit-transition: all .4s ease-in-out;
            transition: all .4s ease-in-out;
  }

  .panel-flip.flip .back {
    z-index: 3;

    -webkit-transform: rotateX(0) rotateY(0);
            transform: rotateX(0) rotateY(0);
  }

  /* -- X axis rotation for click panel -- */
  .click .front {
    cursor: pointer;
    -webkit-transform: rotateX(0);
            transform: rotateX(0);
  }
  .click.flip .front {
    -webkit-transform: rotateX(180deg);
            transform: rotateX(180deg);
  }
  .click .back {
    cursor: pointer;
    -webkit-transform: rotateX(-180deg);
            transform: rotateX(-180deg);
  }
  .click.flip .back {
    -webkit-transform: rotateX(0);
            transform: rotateX(0);
  }
  .flechas-back{
    font-size: 18px;
    text-align: right;
    padding: 10px 10px 0px 0px;
    color: #18194B;
    cursor: pointer;
  }