JSFiddle - React, Tailwind, and code Playground

HTML

<div class="field">
     <input type="text" />
     <ul class ="autocomplete">
          <li>Option 1</li>
          <li>Option 2</li>
          <li>Option 3</li>
          <li>Option 4</li>
          <li>Option 5</li>
     </ul>
</div>

CSS

.field, .field .autocomplete  { width: 400px; background: #CCC; padding: 5px;  }
.field input { width: 380px; padding: 10px; border: 1px #ddd solid; }
.field .autocomplete { border: 1px #333 solid; padding: 0; background: #fff; position: absolute; }