@mixin coords-colors {
  .blue {
    coord { text-shadow: none; }
    .orientation-white .files coords:nth-child(2n+1),
    .orientation-white .ranks coords:nth-child(2n),
    .orientation-black .files coords:nth-child(2n),
    .orientation-black .ranks coords:nth-child(2n+1) {
      color: #DEE3E6;
    }
    .orientation-white .files coord:nth-child(2n),
    .orientation-white .ranks coord:nth-child(2n+1),
    .orientation-black .files coord:nth-child(2n+1),
    .orientation-black .ranks coord:nth-child(2n) {
      color: #788a94;
    }
  }
  .brown {
    coord { text-shadow: none; }
    .orientation-white .files coord:nth-child(2n+1),
    .orientation-white .ranks coord:nth-child(2n),
    .orientation-black .files coord:nth-child(2n),
    .orientation-black .ranks coord:nth-child(2n+1) {
      color: #F0D9B5;
    }
    .orientation-white .files coord:nth-child(2n),
    .orientation-white .ranks coord:nth-child(2n+1),
    .orientation-black .files coord:nth-child(2n+1),
    .orientation-black .ranks coord:nth-child(2n) {
      color: #946f51;
    }
  }
  .green {
    coord { text-shadow: none; }
    .orientation-white .files coords:nth-child(2n+1),
    .orientation-white .ranks coords:nth-child(2n),
    .orientation-black .files coords:nth-child(2n),
    .orientation-black .ranks coords:nth-child(2n+1) {
      color: #FFFFDD;
    }
    .orientation-white .files coord:nth-child(2n),
    .orientation-white .ranks coord:nth-child(2n+1),
    .orientation-black .files coord:nth-child(2n+1),
    .orientation-black .ranks coord:nth-child(2n) {
      color: #6d8753;
    }
  }
}

@mixin coords-colors {
    :root {
    --color-white: #fff;
    --color-black: #fff;
    --shadow: 0 1px 2px #000;
  }

    coord { text-shadow: var(--shadow); }
    .orientation-white .files coords:nth-child(2n+1),
    .orientation-white .ranks coords:nth-child(2n),
    .orientation-black .files coords:nth-child(2n),
    .orientation-black .ranks coords:nth-child(2n+1) {
      color: var(--color-white);
    }
    .orientation-white .files coord:nth-child(2n),
    .orientation-white .ranks coord:nth-child(2n+1),
    .orientation-black .files coord:nth-child(2n+1),
    .orientation-black .ranks coord:nth-child(2n) {
      color: var(--color-black);
    }
}
Use CSS custom properties for inline-coordinates
Use CSS custom properties for inline-coordinates
