JSFiddle - React, Tailwind, and code Playground

HTML

<div class="notes">
  <h2>Title</h2>
  <textarea></textarea>
    <br>
  <button>Save</button>
</div>

CSS

.notes {
    border: 1px solid red;
}

textarea {
    width: calc(100% - 20px);
    margin: auto;
    display: block;
}