Apply CSS styles to an element depending on its child elements [duplicate]

Is it possible to define a CSS style for an element, that is only applied if the matching element contains a specific element (as the direct child item)?

I think this is best explained using an example.

Note: I’m trying to style the parent element, depending on what child elements it contains.

<style>
  /* note this is invalid syntax. I'm using the non-existing
   ":containing" pseudo-class to show what I want to achieve. */
  div:containing div.a { border: solid 3px red; }
  div:containing div.b { border: solid 3px blue; }
</style>

<!-- the following div should have a red border because
     if contains a div with class="a" -->
<div>
  <div class="a"></div>
</div>

<!-- the following div should have a blue border -->
<div>
  <div class="b"></div>
</div>

Note 2: I know I can achieve this using javascript, but I just wondered whether this is possible using some unknown (to me) CSS features.