Edit in JSFiddle

<!-- 
 - CSS3 Preloaders
 - https://danielpietrasik.pl/css3-preloaders/
-->

<div class="box">
  <div class="container">
    <div class="cube">
      <div class="half1">
        <div class="part part1"></div>
        <div class="part part2"></div>
        <div class="part part5"></div>
      </div>
      <div class="half2">
        <div class="part part3"></div>
        <div class="part part4"></div>
        <div class="part part6"></div>
      </div>
    </div>
  </div>
</div>

/**
 * CSS3 Preloaders
 * https://danielpietrasik.pl/css3-preloaders/
 **/

.box {
	width: 150px;
	height: 150px;
	margin: 20px auto;
}

.cube,
.half1,
.half2,
.container {
  transform-style: preserve-3d;
}

.cube {
  width: 100px;
  height: 100px;
  animation: cube 10s forwards infinite;
  transform-origin: center 50px;
  transform-style: preserve-3d;
}

.half1 {
  height: 40px;
  top: 0;
  position: absolute;
  animation: half 10s forwards infinite;
  transform-origin: 50% 100%;
}

.part {
  width: 18px;
  height: 18px;
  border: 1px solid #fff;
  background-color: #fbc2c5;
  position: absolute;
}

.part1 {
  top: 0;
  left: 40px;
  transform-origin: 50% 100%;
  animation: part1 10s forwards infinite;
}

.part2 {
  top: 20px;
  left: 40px;
  transform-origin: 50% 0%;
  animation: part2 10s forwards infinite;
}

.part3 {
  top: 40px;
  left: 40px;
  transform-origin: 50% 0%;
  animation: part3 10s forwards infinite;
}

.part4 {
  top: 60px;
  left: 40px;
  transform-origin: 50% 0%;
  animation: part4 10s forwards infinite;
}

.part5 {
  left: 20px;
  top: 20px;
  transform-origin: 100% 50%;
  animation: part5 10s forwards infinite;
}

.part6 {
  left: 60px;
  top: 40px;
  transform-origin: 0% 50%;
  animation: part6 10s forwards infinite;
}

.container {
  position: relative;
  width: 100px;
  height: 100px;
  margin: 0 auto;
  padding-top: 33px;
  perspective: 300px;
  transform-style: preserve-3d;
}

@keyframes cube {
  0% {
    transform: rotateX(0deg);
  }
  30% {
    transform: rotateX(0deg);
  }
  40% {
    transform: rotateX(45deg) rotateY(0deg) rotateZ(45deg);
  }
  60% {
    transform: rotateX(60deg) rotateY(0deg) rotateZ(45deg);
  }
  65% {
    transform: rotateX(60deg) rotate(45deg) rotateZ(180deg);
  }
  70% {
    transform: rotateX(60deg) rotate(45deg) rotateZ(180deg);
  }
  75% {
    transform: rotateX(60deg) rotate(45deg) rotateZ(360deg);
  }
  80% {
    transform: rotateX(60deg) rotate(45deg) rotateZ(360deg);
  }
  90% {
    transform: rotateX(0deg) rotate(0deg) rotateZ(0deg);
  }
}

@keyframes part1 {
  40% {
    transform: rotateX(0deg);
  }
  50%,
  90% {
    transform: rotateX(-90deg);
  }
}

@keyframes part2 {
  0% {
    opacity: 0;
    transform: rotateX(-179deg);
  }
  10% {
    opacity: 1;
    transform: rotateX(0deg);
  }
  40% {
    background-color: #fbc2c5;
  }
  45% {
    background-color: #f9a4a9;
  }
  80% {
    background-color: #fbc2c5;
  }
  90% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

@keyframes part3 {
  0% {
    opacity: 0;
  }
  10% {
    opacity: 0;
    transform: rotateX(-179deg);
  }
  20% {
    opacity: 1;
    transform: rotateX(0deg);
  }
  40% {
    background-color: #fbc2c5;
  }
  45% {
    background-color: #f9a4a9;
  }
  90% {
    opacity: 1;
    transform: rotateX(0deg);
  }
  100% {
    opacity: 0;
  }
}

@keyframes part4 {
  0% {
    opacity: 0;
  }
  20% {
    opacity: 0;
    transform: rotateX(-179deg);
  }
  30% {
    opacity: 1;
    transform: rotateX(0deg);
  }
  40% {
    transform: rotateX(0deg);
  }
  50% {
    transform: rotateX(90deg);
  }
  90% {
    opacity: 1;
    transform: rotateX(90deg);
  }
  100% {
    opacity: 0;
  }
}

@keyframes part5 {
  0% {
    opacity: 0;
  }
  10% {
    opacity: 0;
    transform: rotateY(-179deg);
  }
  20% {
    opacity: 1;
    transform: rotateY(0deg);
  }
  40% {
    transform: rotateY(0deg);
  }
  50% {
    transform: rotateY(90deg);
  }
  90% {
    transform: rotateY(90deg);
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

@keyframes part6 {
  0% {
    opacity: 0;
  }
  20% {
    opacity: 0;
    transform: rotateY(179deg);
  }
  30% {
    opacity: 1;
    transform: rotateY(0deg);
  }
  40% {
    transform: rotateY(0deg);
  }
  50% {
    transform: rotateY(-90deg);
  }
  90% {
    opacity: 1;
    transform: rotateY(-90deg);
  }
  100% {
    opacity: 0;
  }
}

@keyframes half {
  0% {
    transform: rotateX(0deg);
  }
  50% {
    transform: rotateX(0deg);
  }
  60% {
    transform: rotateX(-90deg);
  }
  90% {
    transform: rotateX(-90deg);
  }
}