<div class="loading">
  <div></div>
  <div></div>
</div>

*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
  background: #333;
  display: grid;
  height: 100vh;
  margin: 0;
  place-items: center center;
}

.loading {
    width: 350px;
    height: 50px;
    display: flex;
    animation: hue-rotate linear 4s 0s infinite;
}
@keyframes hue-rotate {
    100% {filter: hue-rotate(360deg);}
}

.loading div {
    width: 250px;
    height: 50px;
    position: relative;
}

.loading div::before,
.loading div::after {
    content: "";
    display: block;
    width: 50px;
    height: 50px;
    background: rgba(0, 231, 255, 1);
    border-radius: 50%;
    position: absolute;
    box-shadow:
        0 0 5px rgba(0, 231, 255, 1),
        0 0 10px rgba(0, 231, 255, 1),
        0 0 20px rgba(0, 231, 255, 1),
        0 0 40px rgba(0, 231, 255, 1),
        0 0 80px rgba(0, 231, 255, .5),
        0 0 160px rgba(0, 231, 255, .2);
}

.loading div::after {right: 0;}

.loading div:nth-child(1) {animation: rotate1 ease-in-out 2s 0s infinite;}
@keyframes rotate1 {
    0%,50% {transform-origin: 50% 50%;}
    25% {transform: rotate(180deg);}
    26%,50% {transform: rotate(180deg);}
    50.1%,100% {transform-origin: 175px 50%;}
    100% {transform: rotate(540deg);}
}

.loading div:nth-child(2) {
    margin-left: -150px;
    animation: rotate2 ease-in-out 2s 0s infinite;
}
@keyframes rotate2 {
    0%,50% {transform-origin: 50% 50%;}
    0%,25% {transform: rotate(0deg);}
    50% {transform: rotate(180deg);}
    50.1%,100% {transform-origin: 75px 50%;}
    100% {transform: rotate(540deg);}
}