.overlay {
    display: none;
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: 2000;
    background: rgba(255,255,255,0.78);
}
.overlay::before {
    content: "";
    position: absolute;
    width: 86px;
    height: 86px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border-radius: 12px;
    background: #fff;
    box-shadow: 0 18px 45px rgba(15, 23, 42, 0.18);
}
.overlay::after {
    content: "";
    position: absolute;
    width: 48px;
    height: 48px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: url("../img/spinner.png") center / contain no-repeat;
    animation: app-loader-spin 1s linear infinite;
}
@keyframes app-loader-spin {
    from {
        transform: translate(-50%, -50%) rotate(0deg);
    }
    to {
        transform: translate(-50%, -50%) rotate(360deg);
    }
}
body {

}
    body.loading {
        overflow: hidden;
    }
        /* Make spinner image visible when body element has the loading class */
        body.loading .overlay {
            display: block;
        }