.list {
    scrollbar-gutter: stable;
}

.list:focus-visible {
    outline: 2px solid currentColor;
    outline-offset: -2px;
}

.item {
    border-top: 1px solid #ccc;
    line-height: 18px;
    text-align: center;
}

.form {
    display: flex;
    justify-content: center;
    padding: 0.5em;
    flex-wrap: wrap;
    gap: 1em;
    background-color: lightgoldenrodyellow;
    position: sticky;
}

.top0 {
    top: 0;
}

.bottom0 {
    bottom: 0;
}

.list:focus-visible > .top0 {
    box-shadow:
        inset 0 2px currentColor,
        inset 2px 0 currentColor,
        inset -2px 0 currentColor;
}

.list:focus-visible > .bottom0 {
    box-shadow:
        inset 0 -2px currentColor,
        inset 2px 0 currentColor,
        inset -2px 0 currentColor;
}

.btn {
    padding: 0 1em;
    border: 1px solid #ccc;
    background-color: antiquewhite;
}

.inp {
    width: 7em;
    padding: 0.2em 0.5em;
}