<p>Секретне слово: <span>слово</span> (але Ви його не побачите!)</p>
body {
  font-family: sans-serif;
  font-size: 25px;
  color: #666;
  text-align: center;
  padding-top: 36px;
  line-height: 1.4;
}

span {
  visibility: hidden;
}

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