SOURCE

<div class="loader">
  <div class="inner one"></div>
  <div class="inner two"></div>
  <div class="inner three"></div>
</div>

html {
  height: 100%;
}

body {
  /* background-image: radial-gradient(circle farthest-corner at center, #3C4B57 0%, #1C262B 100%); */
  background: f8f8f8;
}

.loader {
  position: absolute;
  top: calc(50% - 32px);
  left: calc(50% - 32px);
  width: 64px;
  height: 64px;
  border-radius: 50%;
  perspective: 800px;
}

.inner {
  position: absolute;
  box-sizing: border-box;
  width: 100%;
  height: 100%;
  border-radius: 50%;  
}

.inner.one {
  left: 0%;
  top: 0%;
  animation: rotate-one 1s linear infinite;
  border-bottom: 3px solid #bc9048;
}

.inner.two {
  right: 0%;
  top: 0%;
  animation: rotate-two 1s linear infinite;
  border-right: 3px solid #bc9048;
}

.inner.three {
  right: 0%;
  bottom: 0%;
  animation: rotate-three 1s linear infinite;
  border-top: 3px solid #bc9048;
}

@keyframes rotate-one {
  0% {
    transform: rotateX(35deg) rotateY(-45deg) rotateZ(0deg);
  }
  100% {
    transform: rotateX(35deg) rotateY(-45deg) rotateZ(360deg);
  }
}

@keyframes rotate-two {
  0% {
    transform: rotateX(50deg) rotateY(10deg) rotateZ(0deg);
  }
  100% {
    transform: rotateX(50deg) rotateY(10deg) rotateZ(360deg);
  }
}

@keyframes rotate-three {
  0% {
    transform: rotateX(35deg) rotateY(55deg) rotateZ(0deg);
  }
  100% {
    transform: rotateX(35deg) rotateY(55deg) rotateZ(360deg);
  }
}