.ok18-loader-wrap {
    position: fixed;
    top: 0;
    left: 0;
    background: #fff;
    width: 100%;
    height: 100%;
    z-index: 99999;
}
.ok18-loader-wrap img {
    text-align: center;
    position: absolute;
    top: 50%;
    left: 50%;
}