[hobnail]

Also similar to mine. But I think that the nth-child and first-child stuff doesn't work on the kobo, but I can't remember for sure. currentColor should be safer than black or some hex value; it does the right thing when the user switches to dark/night mode (white text on a black background); this is true everywhere you want black, not just tables.

table {
    margin-left: auto;
    margin-right: auto;
    border-collapse: collapse;
    margin-top: 1em;
}

table caption {
    font-weight: bold;
    padding-bottom: 0.5em;
}

table.coltwonum td:nth-child(2) {
    text-align: right;
}

table.colsthreenum td:nth-child(3) {
    text-align: right;
}

table.colfournum td:nth-child(4) {
    text-align: right;
}

table.colfivenum td:nth-child(5) {
    text-align: right;
}

td {
    border: 1px solid currentColor;
    empty-cells: show;
    padding: 0.125em;
    text-align: left;
}

tr.final {
   border-top:  2px solid currentColor;
}