<!DOCTYPE html>
<html>
  <style>
    :-moz-any(input, textarea)::placeholder {
      visibility: hidden;
      padding: 20px;
      float: right;
      overflow: visible;
      white-space: pre;

      /*
       * This list could be endless given that all non-whitelisted properties
       * are restricted.
       */
    }
  </style>
  <body>
    <input placeholder='foo'>
    <textarea placeholder='foo'></textarea>
    <!-- for overflow and white-space -->
    <input placeholder='this is a quitelongetextforasmallelement'>
    <textarea placeholder='this is a quitelongetextforasmallelement'></textarea>
  </body>
</html>