<p>This is a paragraph element directly in the body element. Theborder is red by default, since that's what the stylesheet declares for paragraphs, but it will be black when <code>unset</code> is enabled because that is the <code>initial</code> value set by the browser.</p>

<div>
  This is text inside a div element that has a green border because the stylesheet says all divs should have a green border.
  <p>This paragraph has a green border by default, because that's what is inherited from the div element. With <code>unset</code>, the border will become black because, again, that's what the <code>initial</code> value is.</p>
</div>

<button id="toggle">Toggle Unset</button>
body {
  margin: 0 auto;
  max-width: 80%;
}

div {
  border: 5px solid green;
  padding: 0.5rem;
}

p {
  border: 5px solid red;
  padding: 0.5rem;
}

div p {
  border-color: inherit;
}

.unset {
  border-color: unset;
}

button {
  background-image: linear-gradient(to top left, #ff8a00, #e52e71);
  border: none;
  border-radius: 8px;
  color: #fff;
  cursor: pointer;
  font-weight: 800;
  margin-top: 1rem;
  padding: 1rem 1.5rem;
}
button:hover {
  background-image: linear-gradient(to top left, #ff8a00 30%, #e52e71);
  transform: translateY(1px);
}
button:active {
  transform: translateY(2px);
}
$("#toggle").click(function () {
  $("p").toggleClass("unset");
});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js