.alert-progress {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background-color: rgba(0, 0, 0, .2);
    animation: alert-progress-shrink 15s linear forwards;
}

@keyframes alert-progress-shrink {
    from { width: 100%; }
    to { width: 0; }
}

@media (prefers-reduced-motion: reduce) {
    .alert-progress {
        animation: none;
    }
}