html - How can I set margin top/bottom to a li?

Question

Here is my code:

li {
  padding: 5px 4px 6px 7px;
  margin-top: 3px;
  margin-bottom: 3px;
  list-style: none;
}
li + li {
  border-top: 1px solid #eff0f1;
}
li:hover {
  background-color: #f7f8f8;
}

<ul>
  <li>something</li>
  <li>something else</li>
  <li>something else again</li>
</ul>

Answer 1

Your problem is due to collapsing margins - from https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Box_Model/Mastering_margin_collapsing:

Top and bottom margins of blocks are sometimes combined (collapsed) into a single margin whose size is the largest of the margins combined into it, a behavior known as margin collapsing.

To get around this, I would wrap the content of the li in a span or div and put your original li padding on that, and then put the 3px margin as padding on your li instead:

li {
  list-style: none;
  padding: 3px 0; /* this is in place of your margin */
}
li + li {
  border-top: 1px solid #eff0f1;
}
li > span {
  display: block;
  padding: 5px 4px 6px 7px; /* this is you original li padding */
}
li:hover > span {
  background-color: #f7f8f8;
}

<ul>
  <li><span>something</span></li>
  <li><span>something else</span></li>
  <li><span>something else again</span></li>
</ul>