<hr>：主题分隔（水平线）元素

<p>§1: The first rule of Fight Club is: You do not talk about Fight Club.</p>

<hr />

<p>§2: The second rule of Fight Club is: Always bring cupcakes.</p>

hr {
  border: none;
  border-top: 3px double #333333;
  color: #333333;
  overflow: visible;
  text-align: center;
  height: 5px;
}

hr::after {
  background: white;
  content: "§";
  padding: 0 4px;
  position: relative;
  top: -13px;
}

<p>
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  is the first paragraph of text. This is the first paragraph of text.
</p>

<hr />

<p>
  This is the second paragraph of text. This is the second paragraph of text.
  This is the second paragraph of text. This is the second paragraph of text.
</p>