.spinner-border {
    position: fixed;
    width: 400px;
    height: 300px;
    top: 50%;
    bottom: 50%;
    left: 50%;
    right: 50%;
    z-index: 20;
}

.black {
    width: 100%;
    height: 100vh;
    position: fixed;
    background-color: black;
    z-index: 10;
    opacity: 0.5;
}