JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
  parent
  <ul class="block">
    <li>text</li>
    <li>text fdf</li>
    <li>text</li>
    <li>text fsdfds</li>
    <li>text</li>
    <li>text</li>
    <li>text</li>
    <li>text</li>
    <li>text fdf</li>
    <li>text</li>
  </ul>

</div>

CSS

@import url('https://fonts.googleapis.com/css2?family=Neucha&display=swap');


* {
  box-sizing: inherit;
}

html {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Neucha', cursive;
}
.parent {
  position: relative;
  width: 500px;
  margin: auto;
  background: #eee;
}
.block {
  position: absolute;
  top: 100%;
  right: 0;
  display: flex;
  flex-wrap: wrap;
  max-width: 300px;
  margin: 0;
  padding: 0;
  list-style-type: none;
  background: #e5e;
}
li {
  flex-grow: 1;
  padding: 20px;
  margin: 5px;
  background: #eee;
}