JSFiddle - React, Tailwind, and code Playground

HTML

<div class="panel-left">
<div class="very_long">
me very long long long long
</div>
<div class="very_long">
me very lorelong long long long
</div>
<div class="very_long">
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nihil eveniet temporibus, quisquam illum, doloremque sapiente quia voluptatibus rem deserunt iure obcaecati tempore, quibusdam provident omnis quaerat delectus quod consequuntur assumenda?
</div>



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</div>

CSS

body, html {
  margin: 0;
  pading: 0;
  height: 100%;
}
.panel-left {
  height: 100%;
  width: 20%;
  background-color: #EEEEEE;
  overflow-y: auto;
 }
 .very_long {
   background-color: #1E98D3;
   margin-bottom: 1px;
   padding: 5px;
 }