.row {
    text-align: center;
    position: sticky;
    flex: none;
    padding: 0.5em;
    background-color: lightsalmon;
}

.bottom0 {
    bottom: 0;
}

.top0 {
    top: 0;
}

.item {
    border-top: 1px solid #ccc;
    padding: 0.4em;
}