.alert {
    border: none;
    border-radius: 0;
    position: fixed;
    top: 0;
    z-index: 1;
    width: 100%;
    width: -moz-available; /* WebKit-based browsers will ignore this. */
    width: -webkit-fill-available; /* Mozilla-based browsers will ignore this. */
    width: fill-available;
}