How do I select an element only when inside another element?

I have a question regarding CSS selectors. How do I select a <div> with a specific class name only when its inside a <ul> with a class name saft? This CSS class is used elsewhere and I don't want to change the styling everywhere.

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