Editing Template:Static row numbers/styles.css

/* {{pp-template}} */
/**
 * Add a static (unsortable) column of numbers to the left of a table.
 *
 * Table classes:
 * - static-row-numbers: Display column of right-aligned numbers.
 * - static-row-numbers-center: Center align numbers.
 * - static-row-numbers-left: Left align numbers.
 * - static-row-header-text: Display "No." text column label.
 * - static-row-header-hash: Display hash ("#") symbol column label.
 *
 * Row classes:
 * - static-row-header: Disable number and borders.
 * - static-row-numbers-norank: Disable number and keep borders.
 *
 * Table data attributes:
 * - data-srn-limit="#": (#=10) Remove numbers beyond row #.
 *
 * Tested:
 * - Windows 10: (all skins) Chrome, Firefox, Edge.
 * - Android Galaxy S21 (MinervaNeue): Chrome, Firefox.
 * - Wikipedia Android app.
 * - Print.
 * - No JavaScript.
 * - Sticky gadget in Windows browsers (default skin).
 * - Dark Reader browser extention in Windows browsers (default skin).
 *
 * Notes:
 * - Sortable moves to thead any header rows and (after sort) sorttop rows.
 * - Sticky gadget (.mw-sticky-header) moves to thead any wikitable header rows.
 */
.static-row-numbers {
  counter-reset: rowNumber;
}
.static-row-numbers tr::before {
  content: "";
  display: table-cell;
  padding-right: 0.5em;
  padding-left: 0.5em;
  text-align: right;
  vertical-align: inherit;
}
.static-row-numbers.static-row-numbers-center tr::before {
  text-align: center;
}
.static-row-numbers.static-row-numbers-left tr::before {
  text-align: left;
}
.static-row-numbers.wikitable tr::before {
  background-color: var(--background-color-neutral, #eaecf0);
}

/**
 * Add count to all tbody rows without the "static-row-numbers-norank" or
 * "static-row-header" classes. If no thead, then skip the first tbody row.
 */
.static-row-numbers thead + tbody tr:first-child:not(.static-row-header):not(.static-row-numbers-norank)::before,
.static-row-numbers tbody tr:not(:first-child):not(.static-row-header):not(.static-row-numbers-norank)::before {
  counter-increment: rowNumber;
  content: counter(rowNumber);
}

/**
 * Remove count on tbody rows beyond the limit.
 * Note, nth-child cannot be combined with not() to exclude headers and the
 * "static-row-header" and "static-row-numbers-norank" classes:
 * - Table must be sortable to move headers pre-sort to thead.
 * - No sorttop (static-row-header) above sortable data; moved post-sort.
 * - No static-row-numbers-norank in sortable data.
 */
.static-row-numbers.sortable[data-srn-limit="10"] tbody tr:nth-child(n+11)::before {
  content: "";
}

/**
 * Add column label to first row in thead or, if no thead, in tbody.
 */
.static-row-header-text.static-row-numbers thead tr:first-child::before,
.static-row-header-text.static-row-numbers caption + tbody tr:first-child::before,
.static-row-header-text.static-row-numbers tbody:first-child tr:first-child::before {
  content: "No.";
  font-weight: bold;
}
.static-row-header-hash.static-row-numbers thead tr:first-child::before,
.static-row-header-hash.static-row-numbers caption + tbody tr:first-child::before,
.static-row-header-hash.static-row-numbers tbody:first-child tr:first-child::before {
  content: "#";
  font-weight: bold;
}

/**
 * Add borders in numbers column.
 *
 * Windows Firefox tr::before doesn't inherit color, so hard set.
 * Plain table borders on Timeless {{row hover highlight}} mw-datatable.
 */

/* Wikitable. */
.static-row-numbers.wikitable tr::before {
  border: 0 solid var(--border-color-base, #a2a9b1);
}
.static-row-numbers.wikitable thead + tbody tr:first-child:not(.static-row-header)::before,
.static-row-numbers.wikitable tbody tr:not(:first-child):not(.static-row-header)::before {
  border-width: 1px;
}
body.skin-monobook .static-row-numbers.wikitable tr::before {
  border-color: #aaa;
}
body.skin-timeless .static-row-numbers.wikitable tr::before {
  border-color: #c8ccd1;
}

/* Plain with border. */
table[border].static-row-numbers:not(.wikitable) tr::before {
  border: 0 inset var(--color-base, #202122);
}
table[border].static-row-numbers:not(.wikitable) thead + tbody tr:first-child:not(.static-row-header)::before,
table[border].static-row-numbers:not(.wikitable) tbody tr:not(:first-child):not(.static-row-header)::before {
  border-width: 1px;
}
/* Dark mode border colors calc differ for table and tr::before, per engine. */
html.skin-theme-clientpref-night table[border].static-row-numbers:not(.wikitable),
html.skin-theme-clientpref-night table[border].static-row-numbers:not(.wikitable) tr::before,
html.skin-theme-clientpref-night table[border].static-row-numbers:not(.wikitable) th,
html.skin-theme-clientpref-night table[border].static-row-numbers:not(.wikitable) td {
  /* Accessibility: Wikipedia dark mode. */
  border-color: gray;
}
@media (prefers-color-scheme: dark) {
  html.skin-theme-clientpref-os table[border].static-row-numbers:not(.wikitable),
  html.skin-theme-clientpref-os table[border].static-row-numbers:not(.wikitable) tr::before,
  html.skin-theme-clientpref-os table[border].static-row-numbers:not(.wikitable) th,
  html.skin-theme-clientpref-os table[border].static-row-numbers:not(.wikitable) td {
    /* Accessibility: OS dark mode, Wikidedia automatic mode. */
    border-color: gray;
  }
}

/* Plain with optional border + .mw-datatable. */
body.skin-timeless .static-row-numbers.mw-datatable:not(.wikitable) tr::before {
  border: 0 solid #c8ccd1;
}
body.skin-timeless .static-row-numbers.mw-datatable:not(.wikitable) thead + tbody tr:first-child:not(.static-row-header)::before,
body.skin-timeless .static-row-numbers.mw-datatable:not(.wikitable) tbody tr:not(:first-child):not(.static-row-header)::before {
  border-width: 1px;
}