SOURCE

<div class="loaders-16"></div>

[class*="loaders-"] {
    display: inline-block;
    width: 1em;
    height: 1em;
    color: inherit;
    vertical-align: middle;
    pointer-events: none;
}

.loaders-16 {
    -webkit-transform: rotateZ(45deg);
    transform: rotateZ(45deg);
    -webkit-perspective: 1000px;
    perspective: 1000px;
    border-radius: 50%;
}

.loaders-16:before,
.loaders-16:after {
    content: '';
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    width: inherit;
    height: inherit;
    border-radius: 50%;
    -webkit-animation: 1s spin linear infinite;
    animation: 1s spin linear infinite;
}

.loaders-16:before {
    -webkit-transform: rotateX(70deg);
    transform: rotateX(70deg);
}

.loaders-16:after {
    -webkit-transform: rotateY(70deg);
    transform: rotateY(70deg);
    -webkit-animation-delay: .4s;
    animation-delay: .4s;
}

@-webkit-keyframes rotate {
    0% {
    -webkit-transform: translate(-50%, -50%) rotateZ(0deg);
    transform: translate(-50%, -50%) rotateZ(0deg);
    }

    100% {
    -webkit-transform: translate(-50%, -50%) rotateZ(360deg);
    transform: translate(-50%, -50%) rotateZ(360deg);
    }
}

@keyframes rotate {
    0% {
    -webkit-transform: translate(-50%, -50%) rotateZ(0deg);
    transform: translate(-50%, -50%) rotateZ(0deg);
    }

    100% {
    -webkit-transform: translate(-50%, -50%) rotateZ(360deg);
    transform: translate(-50%, -50%) rotateZ(360deg);
    }
}

@keyframes spin {

    0%,
    100% {
    box-shadow: .2em 0px 0 0px currentcolor;
    }

    12% {
    box-shadow: .2em .2em 0 0 currentcolor;
    }

    25% {
    box-shadow: 0 .2em 0 0px currentcolor;
    }

    37% {
    box-shadow: -.2em .2em 0 0 currentcolor;
    }

    50% {
    box-shadow: -.2em 0 0 0 currentcolor;
    }

    62% {
    box-shadow: -.2em -.2em 0 0 currentcolor;
    }

    75% {
    box-shadow: 0px -.2em 0 0 currentcolor;
    }

    87% {
    box-shadow: .2em -.2em 0 0 currentcolor;
    }
}