<ul>
  <li>ダミーテキスト</li>
  <li>ダミーテキスト</li>
  <li>ダミーテキスト</li>
  <li>ダミーテキスト</li>
</ul>

li:not(:first-of-type) {
  border-top: 1px solid #000;
}

ul {
  list-style:none;
  padding: 0;
  margin: 0;
}
li {
  padding: 10px;
}

External CSS

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External JavaScript

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