.spinner-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    /* Was start/start. Under BS3 `.spinner-border` had no styles at all, so this
       overlay's spinner was invisible and the visible loader was DataTables' own
       centered `div.dataTables_processing` dots -- the corner alignment never
       showed. BS5 makes `.spinner-border` a real component, so start/start parked
       the loader in the top-left corner. A centered copy of this rule was added to
       Admin.css during the migration, but `spinner.css` loads AFTER `admin.css` in
       the adminCss bundle (BundleConfig.cs), so it never won the cascade. Centered
       here, where the selector actually resolves; the Admin.css copy was removed. */
    justify-content: center;
    align-items: center;
    z-index: 1050;
}

.spinner-backdrop {
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5); /* Semi-transparent black */
    z-index: 1;
}

.spinner-border {
    z-index: 2; /* Ensure spinner is on top */
    width: 3rem;
    height: 3rem;
}