.overlay {
    position: fixed;
    display: block;
    text-align: center;
    color: #FFF;
    background-color: rgba(0,0,0, .5);
    height: 100%;
    width: 100%;
    top: 0;
    left: 0;
    z-index: 1000;
    visibility: hidden;
}

.spanner {
    position: fixed;
    top: 50%;
    left: 0;
    background: transparent;
    width: 100%;
    display: block;
    text-align: center;
    color: #FFF;
    transform: translateY(-50%);
    z-index: 1000;
    visibility: hidden;
}

.show {
    visibility: visible;
}

.spanner, .overlay {
    -webkit-transition: all 0.3s;
    -moz-transition: all 0.3s;
    transition: all 0.3s;
}

.overlay.show {
    opacity: 0.5;
}

.spanner.show {
    opacity: 1;
}

.loader,
.loader:before,
.loader:after {
    border-radius: 50%;
    width: 2.5em;
    height: 2.5em;
    -webkit-animation-fill-mode: both;
    animation-fill-mode: both;
    -webkit-animation: load7 1.8s infinite ease-in-out;
    animation: load7 1.8s infinite ease-in-out;
}

.loader {
    color: #ffffff;
    font-size: 10px;
    margin: 80px auto;
    position: relative;
    text-indent: -9999em;
    -webkit-transform: translateZ(0);
    -ms-transform: translateZ(0);
    transform: translateZ(0);
    -webkit-animation-delay: -0.16s;
    animation-delay: -0.16s;
}


.spanner.show .center {
    margin: 0 auto;
}

.loader {
    border: 16px solid #f3f3f3;
    border-radius: 50%;
    border-top: 16px solid #757A7D;
    width: 70px;
    height: 70px;
    margin: 5em;
    margin-top: 15em;
    -webkit-animation: spin 2s linear infinite; /* Safari */
    animation: spin 2s linear infinite;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}