Zero element CSS loader

loader.css

.loading {
    position: relative;
}

.loading:before {
    content: "";
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    background: rgba(255,255,255,0.75);
    z-index: 1010;
}
.loading:after {
    content: "";
    display: block;
    position: absolute;
    top: 50%;
    left: 50%;
    width: 42px;
    height: 42px;
    margin: -21px 0 0 -21px;
    z-index: 1020;

    background: url("loader.svg");
    background-size: contain;
    background-position: 50% 50%;

    -webkit-animation-name: spin;
    -webkit-animation-duration: 600ms;
    -webkit-animation-iteration-count: infinite;
    -webkit-animation-timing-function: linear;
    -moz-animation-name: spin;
    -moz-animation-duration: 600ms;
    -moz-animation-iteration-count: infinite;
    -moz-animation-timing-function: linear;
    -ms-animation-name: spin;
    -ms-animation-duration: 600ms;
    -ms-animation-iteration-count: infinite;
    -ms-animation-timing-function: linear;
}
@-moz-keyframes spin {
    from { -moz-transform: rotate(0deg); }
    to { -moz-transform: rotate(360deg); }
}
@-webkit-keyframes spin {
    from { -webkit-transform: rotate(0deg); }
    to { -webkit-transform: rotate(360deg); }
}
@keyframes spin {
    from {transform:rotate(0deg);}
    to {transform:rotate(360deg);}
}

loader.svg