JSFiddle - React, Tailwind, and code Playground

HTML

<div class="sideMenu"></div>

<h1>Page Title</h1>
<form>
  <fieldset>

    <div class="rowContainer">
      <label>Label:</label>
      <input type="text" />
    </div>

    <div class="rowContainer">
      <label>Label:</label>
      <input type="text" />
    </div>

    <div class="rowContainer">
      <label>Label:</label>
      <input type="text" />
    </div>
    
  </fieldset>
</form>

<button class="add">Add row</button>

CSS

* {
  margin: 0;
  padding: 0
}

body,
html {
  width: 100%;
  height: 100%;
}

fieldset {
  padding: 10px;
}

.sideMenu {
  width: 200px;
  height: 100%;
  background-color: #1c1c1c;
  float: left;
}

input {
  width: 100%;
  max-width: 400px;
  height: 40px;
  display: block;
  margin-bottom: 20px;
  color: #000;
}

JavaScript

// just a quick function to add more inputs

$(document).ready(function() {
	$(".add").on("click", function() {
		$("fieldset").append("<div class='rowContainer'><label>Label:</label><input type='text' /></div>");
	});
});