JSFiddle - React, Tailwind, and code Playground

HTML

<ol>
  <li>
    <ol>
      <li>A</li>
      <li>B</li>
      <li class="x">X</li>
    </ol>
  </li>
  <li>
    <ol>
      <li>A</li>
      <li>C</li>
      <li class="x">X</li>
    </ol>
  </li>
  <li>
    <ol>
      <li>A</li>
      <li>D</li>
      <li class="x">X</li>
    </ol>
  </li>
</ol>

CSS

li li:not(.x):last-child {
  color: red;
}