Comment by deleerium

For those who want something more traditional I've modified to have a slight orange tint on the title bar, and higher contrast for text. Seems to be better for a11y too.

Screenshot: https://imgur.com/a/XW1OCYb

@media (prefers-color-scheme: dark) { body { background-color: #232834; }

  #hnmain { background-color: #1F2430; }

  a:link.storylink,
  #hnmain > tbody > tr:first-child > td a,
  .commtext, .commtext a:link,
  td {
    color: #fafafa;
  }

  #hnmain > tbody > tr:first-child > td { background-color: #4a3226; }

  a:link,
  .sitebit, .subtext, .sitestr, .subtext a:link,
  .rank, a.morelink,
  .yclinks a,
  .comhead a:link, .comhead,
  .hnmore a:link, .reply a:link {
    color: #8c96ac;
  }

  .pagetop { color: #795848; }

  a:visited {
    color: #979cf4;
  }

  .votearrow {
    overflow: visible;
    position: relative;
  }

  .votearrow::before {
    content: "";
    width: 0;
    height: 0;
    left: 1px;
    top: 3px;
    display: block;
    position: absolute;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-bottom: 7px solid #bebfd1;
  }

}

edit: fixed imgur link and added full css