.sk-fading-circle {
    margin: 2em auto;
    width: 40px;
    height: 40px;
    position: relative;
}

    .sk-fading-circle .sk-circle {
        width: 100%;
        height: 100%;
        position: absolute;
        left: 0;
        top: 0;
    }

        .sk-fading-circle .sk-circle:before {
            content: '';
            display: block;
            margin: 0 auto;
            width: 15%;
            height: 15%;
            background-color: #333;
            border-radius: 100%;
            -webkit-animation: sk-circleFadeDelay 1.2s infinite ease-in-out both;
            animation: sk-circleFadeDelay 1.2s infinite ease-in-out both;
        }

    .sk-fading-circle .sk-circle2 {
        -webkit-transform: rotate(30deg);
        -ms-transform: rotate(30deg);
        transform: rotate(30deg);
    }

    .sk-fading-circle .sk-circle3 {
        -webkit-transform: rotate(60deg);
        -ms-transform: rotate(60deg);
        transform: rotate(60deg);
    }

    .sk-fading-circle .sk-circle4 {
        -webkit-transform: rotate(90deg);
        -ms-transform: rotate(90deg);
        transform: rotate(90deg);
    }

    .sk-fading-circle .sk-circle5 {
        -webkit-transform: rotate(120deg);
        -ms-transform: rotate(120deg);
        transform: rotate(120deg);
    }

    .sk-fading-circle .sk-circle6 {
        -webkit-transform: rotate(150deg);
        -ms-transform: rotate(150deg);
        transform: rotate(150deg);
    }

    .sk-fading-circle .sk-circle7 {
        -webkit-transform: rotate(180deg);
        -ms-transform: rotate(180deg);
        transform: rotate(180deg);
    }

    .sk-fading-circle .sk-circle8 {
        -webkit-transform: rotate(210deg);
        -ms-transform: rotate(210deg);
        transform: rotate(210deg);
    }

    .sk-fading-circle .sk-circle9 {
        -webkit-transform: rotate(240deg);
        -ms-transform: rotate(240deg);
        transform: rotate(240deg);
    }

    .sk-fading-circle .sk-circle10 {
        -webkit-transform: rotate(270deg);
        -ms-transform: rotate(270deg);
        transform: rotate(270deg);
    }

    .sk-fading-circle .sk-circle11 {
        -webkit-transform: rotate(300deg);
        -ms-transform: rotate(300deg);
        transform: rotate(300deg);
    }

    .sk-fading-circle .sk-circle12 {
        -webkit-transform: rotate(330deg);
        -ms-transform: rotate(330deg);
        transform: rotate(330deg);
    }

    .sk-fading-circle .sk-circle2:before {
        -webkit-animation-delay: -1.1s;
        animation-delay: -1.1s;
    }

    .sk-fading-circle .sk-circle3:before {
        -webkit-animation-delay: -1s;
        animation-delay: -1s;
    }

    .sk-fading-circle .sk-circle4:before {
        -webkit-animation-delay: -0.9s;
        animation-delay: -0.9s;
    }

    .sk-fading-circle .sk-circle5:before {
        -webkit-animation-delay: -0.8s;
        animation-delay: -0.8s;
    }

    .sk-fading-circle .sk-circle6:before {
        -webkit-animation-delay: -0.7s;
        animation-delay: -0.7s;
    }

    .sk-fading-circle .sk-circle7:before {
        -webkit-animation-delay: -0.6s;
        animation-delay: -0.6s;
    }

    .sk-fading-circle .sk-circle8:before {
        -webkit-animation-delay: -0.5s;
        animation-delay: -0.5s;
    }

    .sk-fading-circle .sk-circle9:before {
        -webkit-animation-delay: -0.4s;
        animation-delay: -0.4s;
    }

    .sk-fading-circle .sk-circle10:before {
        -webkit-animation-delay: -0.3s;
        animation-delay: -0.3s;
    }

    .sk-fading-circle .sk-circle11:before {
        -webkit-animation-delay: -0.2s;
        animation-delay: -0.2s;
    }

    .sk-fading-circle .sk-circle12:before {
        -webkit-animation-delay: -0.1s;
        animation-delay: -0.1s;
    }

@-webkit-keyframes sk-circleFadeDelay {
    0%, 39%, 100% {
        opacity: 0;
    }

    40% {
        opacity: 1;
    }
}

@keyframes sk-circleFadeDelay {
    0%, 39%, 100% {
        opacity: 0;
    }

    40% {
        opacity: 1;
    }
}