JSFiddle - React, Tailwind, and code Playground

HTML

<div class="test"  style="position: absolute; height: 200px; overflow: auto; background-color: yellow; ">
    <div style="height: 2000px;">
        one two three four five six
    </div>
</div>

CSS

.test div:after {
    content: '---';
    color: transparent;
}