#loader {
    display: none;
    position: absolute;
    top: calc(50vh - 185px);
    left: calc(50vw - 186px);
}

#loader img {
    border-radius: 10%;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
}

#loader.show {
    display: block;
}