splas/assets/scss/animation.scss

@keyframes animate-top {
  0% {
    background: #8b2ef4; /* Old browsers */
  }
  
  100% {
    color: #474747;
    
    transform: 
      translateX(0px) 
      translateY(50%) 
      translateZ(5px) 
      rotateX(-90deg)
      rotateY(0deg)
      rotateZ(0deg);
  }
}

@keyframes animate-bottom {
  0% {
    color: #474747;
    opacity: 1;
  }
  
  100% {
    transform: 
      translateX(0) 
      translateY(0) 
      translateZ(0) 
      rotateX(0deg) 
      rotateY(0deg)
      rotateZ(0deg);
    
    opacity: 1;
  }
}

.number {
  position: relative;
}

.number span {
  position: absolute;
  display: block;
  font-weight: bold;
  text-align: center;
  
  box-sizing: border-box;
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
  
  color: white;
  
  width: 100%;
  height: 100%;
  perspective: 7.14em;
  
}

.number span:before {
  display: block;
  height: 50%;
  overflow: hidden;
  border-radius: 20% 20% 0 0;
  
  background: #8b2ef4; /* Old browsers */
}

.number span:after {
  display: block;
  height: 50%;
  overflow: hidden;
  line-height: 0;
  
  border-radius: 0 0 20% 20%;
  
  transition: color 100ms, background-color 100ms;
  
  background: #7F1BF2; /* Old browsers */
}


.flip .primary:before {
  animation: animate-top 250ms;
  -moz-animation-fill-mode: forwards;
  
  -webkit-animation: animate-top 250ms;
  -webkit-animation-fill-mode: forwards;
  
  
  background: #7F1BF2; /* Old browsers */
}

.flip .primary:after {
  animation: animate-bottom 250ms;
  -moz-animation-fill-mode: forwards;
  animation-delay: 250ms;
  
  -webkit-animation: animate-bottom 250ms;
  -webkit-animation-fill-mode: forwards;
  -webkit-animation-delay: 250ms;
}

.primary:after {
  opacity: 0;
  transform: 
    translateX(0) 
    translateY(-0.0em) 
    translateZ(0.35em) 
    rotateX(91deg) 
    rotateY(0deg) 
    rotateZ(0deg);
}

.primary {
  z-index: 2;
}

.secondary {
  z-index: 1;
}

/* Number 0 */

[data-number="0"] span.primary:before {
  content: "0";
}

[data-number="0"] span.secondary:after {
  content: "0";
}

[data-number="0"] span.secondary:before {
  content: attr(title);
}

[data-number="0"] span.primary:after {
  content: attr(title);
}

/* Number 9 */

[data-number="9"] span.primary:before {
  content: "9";
}

[data-number="9"] span.secondary:after {
  content: "9";
}

[data-number="9"] span.secondary:before {
  content: attr(title);
}

[data-number="9"] span.primary:after {
  content: attr(title);
}

/* Number 8 */

[data-number="8"] span.primary:before {
  content: "8";
}

[data-number="8"] span.secondary:after {
  content: "8";
}

[data-number="8"] span.secondary:before {
  content: attr(title);
}

[data-number="8"] span.primary:after {
  content: attr(title);
}

/* Number 7 */

[data-number="7"] span.primary:before {
  content: "7";
}

[data-number="7"] span.secondary:after {
  content: "7";
}

[data-number="7"] span.secondary:before {
  content: attr(title);
}

[data-number="7"] span.primary:after {
  content: attr(title);
}

/* Number 6 */

[data-number="6"] span.primary:before {
  content: "6";
}

[data-number="6"] span.secondary:after {
  content: "6";
}

[data-number="6"] span.secondary:before {
  content: attr(title);
}

[data-number="6"] span.primary:after {
  content: attr(title);
}

/* Number 5 */

[data-number="5"] span.primary:before {
  content: attr(title);
}

[data-number="5"] span.secondary:after {
  content: attr(title);
}

[data-number="5"] span.secondary:before {
  content: attr(title);
}

[data-number="5"] span.primary:after {
  content: attr(title);
}

/* Number 4 */

[data-number="4"] span.primary:before {
  content: "4";
}

[data-number="4"] span.secondary:after {
  content: "4";
}

[data-number="4"] span.secondary:before {
  content: attr(title);
}

[data-number="4"] span.primary:after {
  content: attr(title);
}

/* Number 3 */

[data-number="3"] span.primary:before {
  content: attr(title);
}

[data-number="3"] span.secondary:after {
  content: attr(title);
}

[data-number="3"] span.secondary:before {
  content: attr(title);
}

[data-number="3"] span.primary:after {
  content: attr(title);
}

/* Number 2 */

[data-number="2"] span.primary:before {
  content: "2";
}

[data-number="2"] span.secondary:after {
  content: "2";
}

[data-number="2"] span.secondary:before {
  content: attr(title);
}

[data-number="2"] span.primary:after {
  content: attr(title);
}

/* Number 1 */

[data-number="1"] span.primary:before {
  content: "1";
}

[data-number="1"] span.secondary:after {
  content: "1";
}

[data-number="1"] span.secondary:before {
  content: attr(title);
}

[data-number="1"] span.primary:after {
  content: attr(title);
}