$perspective-space: 600px;

.ak-tilt-left, .ak-tilt-right {
  transition: all 0.3s;
  -webkit-transition: all 0.3s;
}

.ak-tilt-left {
  transform: perspective($perspective-space) rotateY(-10deg);
  -webkit-transform: perspective($perspective-space) rotateY(-10deg);
}

.ak-tilt-left:hover, .ak-tilt-left:active {
  transform: perspective($perspective-space) rotateY(-20deg);
  -webkit-transform: perspective($perspective-space) rotateY(-20deg);
}

.ak-tilt-right {
  transform: perspective($perspective-space) rotateY(10deg);
  -webkit-transform: perspective($perspective-space) rotateY(10deg);
}

.ak-tilt-right:hover, .ak-tilt-right:active {
  transform: perspective($perspective-space) rotateY(20deg);
  -webkit-transform: perspective($perspective-space) rotateY(20deg);
}