How to do element selection inside another element?

Question

I have a question about CSS selectors. When a

with a specific class name is inside a

with a class name saft How should I choose it? This CSS class is used elsewhere and I don't want to change the style everywhere.

<div id="floater">
    <ul class="saft">
        <li><div class="textSlide"></li>
    </ul>
</div>

Answer 1

Just execute:

ul.saft .textSlide {

This will achieve the functionality you require

Answer 2

Just use the CSS descendant selector (one space) between the parent element and the child element:

ul.saft div.textSlide {
    /* CSS规则 */
}

* {
  margin: 0;
  padding: 0
}

li {
  list-style-type: none;
}

ul.saft div.textSlide {
  background-color: #f90;
  font-weight: #000;
}

<ul class="saft">
  <li>
    <div class="textSlide">在textSlide类元素中的一些文本</div>
  </li>
</ul>
<div class="textSlide">更多文本，也在textSlide元素中</div>