Gestaltung von CSS-Scrollbalken

.poem {
  width: 300px;
  height: 100px;
  border: 1px solid;
}

.poem {
  overflow: scroll;
  scrollbar-color: #0b4f4a #5f9e98;
  scrollbar-width: thin;
}

<blockquote class="poem">
  <h3>A Small Needful Fact</h3>
  <pre>
Is that Eric Garner worked
for some time for the Parks and Rec.
Horticultural Department, which means,
perhaps, that with his very large hands,
perhaps, in all likelihood,
he put gently into the earth
some plants which, most likely,
some of them, in all likelihood,
continue to grow, continue
to do what such plants do, like house
and feed small and necessary creatures,
like being pleasant to touch and smell,
like converting sunlight
into food, like making it easier
for us to breathe.
</pre>
  <p>
    - <a href="https://onbeing.org/poetry/a-small-needful-fact/">Ross Gay</a>
  </p>
</blockquote>