Examples

HTML

<!-- Learn about this code on MDN: https://developer.mozilla.org/en-US/docs/Web/CSS/:not -->

<form class="editform">
  <div>
    <div class="k-grid">
      <p>I am a paragraph.</p>
      <p class="fancy">
      <span class="notfancy">I am so very fancy!</span></p>
      <div class="fancy">I am NOT a paragraph.</div>
    </div>
  </div>
</form>

CSS

.fancy {
  text-shadow: 2px 2px 3px gold;
}

/* <p> elements that are not in the class `.fancy` */
form.editform div:not(.k-grid) p:not(.fancy) {
  color: green;
}

/* Elements that are not <p> elements */ 
body :not(p) {
  text-decoration: underline;
}

/* Elements that are not <div> and not <span> elements */
body :not(div):not(span) {
  font-weight: bold;
}

/* Elements that are not `.crazy` or `.fancy` */
/* Note that this syntax is not well supported yet. */
body :not(.crazy, .fancy) {
  font-family: sans-serif;
}