<!--Ejemplo-->
<div id="unico">Pikachu</div>
<div id="unico">Raichu</div>
<!--Esto no se debe de hacer-->
#unico {
  background: yellow;
  margin: 1rem;
  padding: 1rem;
  text-align: center;
  color: orange;
  font-size: 2rem;
}

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External JavaScript

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