JSFiddle - React, Tailwind, and code Playground

HTML

<div class="selectWrapper">
  <select class="selectBox">
  <option>Option 1</option>
  <option>Option 2</option>
  <option>Option 3</option>
  <option>Option 4</option>
</select>
</div>

CSS

.selectWrapper{
  border-radius:36px;
  display:inline-block;
  overflow:hidden;
  background:#cccccc;
  border:1px solid #cccccc;
}
.selectBox{
  width:140px;
  height:40px;
  border:0px;
  outline:none;
}