<summary>: 披露摘要元素

<details>
  <summary>
    I have keys but no doors. I have space but no room. You can enter but can’t
    leave. What am I?
  </summary>
  A keyboard.
</details>

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  border-radius: 4px;
  padding: 0.5em 0.5em 0;
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  margin: -0.5em -0.5em 0;
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  border-bottom: 1px solid #aaaaaa;
  margin-bottom: 0.5em;
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<details open>
  <summary>Overview</summary>
  <ol>
    <li>Cash on hand: $500.00</li>
    <li>Current invoice: $75.30</li>
    <li>Due date: 5/6/19</li>
  </ol>
</details>

<details open>
  <summary><h4>Overview</h4></summary>
  <ol>
    <li>Cash on hand: $500.00</li>
    <li>Current invoice: $75.30</li>
    <li>Due date: 5/6/19</li>
  </ol>
</details>

<details open>
  <summary><strong>Overview</strong></summary>
  <ol>
    <li>Cash on hand: $500.00</li>
    <li>Current invoice: $75.30</li>
    <li>Due date: 5/6/19</li>
  </ol>
</details>

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  font-size: 1rem;
  font-family: "Open Sans", "Calibri", sans-serif;
  border: solid;
  padding: 2px 6px;
  margin-bottom: 1em;
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:is(::-webkit-details-marker) {
  content: "+ ";
  font-family: monospace;
  color: red;
  font-weight: bold;
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  content: "− ";
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  list-style: none;
  &::after {
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    background-color: darkgreen;
    border-radius: 1em;
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    content: "−";
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  display: none;
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<h1>Quotes from Helen Keller</h1>

<details>
  <summary>On women's rights</summary>
  <p>
    <q>We have prayed, we have coaxed, we have begged, for the vote, with the
      hope that men, out of chivalry, would bestow equal rights upon women and
      take them into partnership in the affairs of the state. We hoped that
      their common sense would triumph over prejudices and stupidity. We thought
      their boasted sense of justice would overcome the errors that so often
      fetter the human spirit; but we have always gone away empty-handed. We
      shall beg no more.</q>
  </p>
</details>

<details>
  <summary>On optimism</summary>
  <p>
    <q>Optimism is the faith that leads to achievement; nothing can be done
      without hope.</q>
  </p>
</details>