<div id="container">
  <div id="inner">
    <div class="demo-img">
      <div class="demo-overlay">
        <svg
          version="1.1"
          id="svg"
          xmlns="http://www.w3.org/2000/svg"
          xmlns:xlink="http://www.w3.org/1999/xlink"
          x="0px"
          y="0px"
          width="60px"
          height="60px"
          viewBox="0 0 612 612"
          xml:space="preserve"
        >
          <path
            d="M535.5,0h-153v76.5h114.75c21.133,0,38.25,17.136,38.25,38.25V229.5H612v-153C612,34.253,577.747,0,535.5,0z M0,76.5v153
                                        h76.5V114.75c0-21.133,17.117-38.25,38.25-38.25H229.5V0h-153C34.253,0,0,34.253,0,76.5z M76.5,497.25V382.5H0v153
                                        C0,577.747,34.253,612,76.5,612h153v-76.5H114.75C93.617,535.5,76.5,518.383,76.5,497.25z M535.5,497.25
                                        c0,21.133-17.117,38.25-38.25,38.25H382.5V612h153c42.247,0,76.5-34.253,76.5-76.5v-153h-76.5V497.25z"
          />
        </svg>
      </div>
    </div>
  </div>
</div>

body {
  width: 100%;
  min-height: 100vh;

  margin: 0;

  display: flex;
  justify-content: center;
  align-items: center;

  background-color: rgb(223, 223, 223);
}

#container {
  perspective: 30px;
}

#inner {
  transition: transform 0.5s;
  -webkit-transition: transform 0.5s;
  box-shadow: 2px 2px 50px rgba(0, 0, 0, 0.2);
}

/*============================================================
 * EXTRAS
 *============================================================*/

.demo-img {
  /* Photo by David Marcu on Unsplash */
  border: solid white 15px;
  background-image: url("https://images.unsplash.com/photo-1469474968028-56623f02e42e?auto=format&fit=crop&w=1953&q=80");
  background-size: cover;
  background-repeat: no-repeat;
}

#container:hover .demo-overlay {
  opacity: 1;
}

#container:hover {
  cursor: pointer;
}

.demo-overlay {
  width: 25em;
  padding: 10em 0;
  opacity: 0;
  background-color: rgba(0, 0, 0, 0.5);
  transition: opacity 0.4s;
}

.demo-overlay svg {
  display: block;
  margin: 0 auto;
  fill: white;
}

;(function () {
  // Init
  var container = document.getElementById("container"),
    inner = document.getElementById("inner")

  // Mouse
  var mouse = {
    _x: 0,
    _y: 0,
    x: 0,
    y: 0,
    updatePosition: function (event) {
      var e = event || window.event
      this.x = e.clientX - this._x
      this.y = (e.clientY - this._y) * -1
    },
    setOrigin: function (e) {
      this._x = e.offsetLeft + Math.floor(e.offsetWidth / 2)
      this._y = e.offsetTop + Math.floor(e.offsetHeight / 2)
    },
    show: function () {
      return "(" + this.x + ", " + this.y + ")"
    },
  }

  // Track the mouse position relative to the center of the container.
  mouse.setOrigin(container)

  //----------------------------------------------------

  var counter = 0
  var refreshRate = 10
  var isTimeToUpdate = function () {
    return counter++ % refreshRate === 0
  }

  //----------------------------------------------------

  var onMouseEnterHandler = function (event) {
    update(event)
  }

  var onMouseLeaveHandler = function () {
    inner.style = ""
  }

  var onMouseMoveHandler = function (event) {
    if (isTimeToUpdate()) {
      update(event)
    }
  }

  //----------------------------------------------------

  var update = function (event) {
    mouse.updatePosition(event)
    updateTransformStyle(
      (mouse.y / inner.offsetHeight / 2).toFixed(2),
      (mouse.x / inner.offsetWidth / 2).toFixed(2)
    )
  }

  var updateTransformStyle = function (x, y) {
    var style = "rotateX(" + x + "deg) rotateY(" + y + "deg)"
    inner.style.transform = style
    inner.style.webkitTransform = style
    inner.style.mozTranform = style
    inner.style.msTransform = style
    inner.style.oTransform = style
  }

  //--------------------------------------------------------

  container.onmousemove = onMouseMoveHandler
  container.onmouseleave = onMouseLeaveHandler
  container.onmouseenter = onMouseEnterHandler
})()