#loading {
    position: fixed;
    z-index: 99999;
    height: 2em;
    width: 2em;
    overflow: visible;
    margin: auto;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
}

    /* Transparent Overlay */
    #loading:before {
        content: '';
        display: block;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: rgba(0,0,0,0.3);
    }

    /* :not(:required) hides these rules from IE9 and below */
    #loading:not(:required) {
        /* hide "loading..." text */
        font: 0/0 a;
        color: transparent;
        text-shadow: none;
        background-color: transparent;
        border: 0;
    }

.spinner {
    width: 40px;
    height: 40px;
    margin: 100px auto;
    background-color: #333;
    border-radius: 100%;
    -webkit-animation: sk-scaleout 1.0s infinite ease-in-out;
    animation: sk-scaleout 1.0s infinite ease-in-out;
}

@-webkit-keyframes sk-scaleout {
    0% {
        -webkit-transform: scale(0);
    }

    100% {
        -webkit-transform: scale(1.0);
        opacity: 0;
    }
}

@keyframes sk-scaleout {
    0% {
        -webkit-transform: scale(0);
        transform: scale(0);
    }

    100% {
        -webkit-transform: scale(1.0);
        transform: scale(1.0);
        opacity: 0;
    }
}