HTML hidden 全局属性

<p>
  This content should be read right now, as it is important. I am so glad you
  are able to find it!
</p>

<p hidden>
  This content is not relevant to this page right now, so should not be seen.
  Nothing to see here. Nada.
</p>

p {
  background: #ffe8d4;
  border: 1px solid #f69d3c;
  padding: 5px;
  border-radius: 5px;
}

<span hidden>I'm hidden</span>
<span hidden="">I'm also hidden</span>
<span hidden="hidden">I'm hidden too!</span>
<span hidden="bananas">I'm equally as hidden!</span>

<span hidden="until-found">I'm hidden until found</span>

<div hidden>
  <script>
    console.warn("Boo! I'm hidden *and* running!");
  </script>
</div>

<div>I'm not hidden</div>
<div hidden>I'm hiding!</div>
<div>I'm not hidden, either</div>

div {
  height: 40px;
  width: 300px;
  border: 5px dashed black;
  margin: 1rem 0;
  padding: 1rem;
  font-size: 2rem;
}

<a href="#until-found-box">Go to hidden content</a>

<div>I'm not hidden</div>
<div id="until-found-box" hidden="until-found">Hidden until found</div>
<div>I'm hidden</div>

<button id="reset">Reset</button>

div {
  height: 40px;
  width: 300px;
  border: 5px dashed black;
  margin: 1rem 0;
  padding: 1rem;
  font-size: 2rem;
}

div#until-found-box {
  color: red;
  border: 5px dotted red;
  background-color: lightgray;
}

#until-found-box {
  scroll-margin-top: 200px;
}

const untilFound = document.querySelector("#until-found-box");
untilFound.addEventListener(
  "beforematch",
  () => (untilFound.textContent = "I've been revealed!"),
);

document.querySelector("#reset").addEventListener("click", () => {
  document.location.hash = "";
  document.location.reload();
});