JSFiddle - React, Tailwind, and code Playground

HTML

<form action="">

  <fieldset>
    <input type="text">
    <input type="text">
    <input type="text">
  </fieldset>
  <fieldset>
    <textarea></textarea>
  </fieldset>
  <button>btn</button>
</form>

CSS

* {
  box-sizing: border-box
}

html,
body {
  height: 100%;
  padding: 0;
  margin: 0;
}

form {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  width: 80%;
  padding: 20px;
  margin: 20px auto;
  background: #eee;
}

fieldset {
  width: 50%;
  margin: 0;
}
input {
  width: 100%;
}
input:not(:first-child) {
  margin-top: 10px;
}
textarea {
  width: 100%;
  height: 100%;
}
button {
  margin-top: 10px;
}