JSFiddle - React, Tailwind, and code Playground

HTML

<form method="post" class="box">
    <label for="add_to_cart_itemX">$19.95</label>
    <input type="button" name="add_to_cart_itemX" id="add_to_cart_itemX" value="Add to Cart">
    <input type="number" name="quantity" value="1">
  </form>

CSS

.box {
  border: 0.3em solid #ccc;
  padding: 1em;
  display: inline-block;
}
label, input {
  margin-right: 3em;
  line-height: 1.8em;
}
input[type=number] {
  width: 3em;
}