.bslib-sidebar-layout>.sidebar>.sidebar-content {
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    padding-top: 1.5rem;
    padding-right: 1.5rem;
    padding-bottom: 1.5rem;
    padding-left: 1.5rem;

.shiny-notification {
             position:fixed;
             top: calc(0%);
             left: calc(50% - 150px);
             }