Attributing CSS class to element

Attributing CSS class to element

Assuming I wanted to attribute the text-shadow: green; attribute to every
<h2> element occouring inside an element with the classes .dark and
ux-bannerwhat CSS code would achieve this?
<div class="dark ux-banner">
<div class="the attributed classes of this element will vary">
<h2>TARGET THIS ELEMENT
</h2>
</div>
</div>
As in the above example <h2> element will be wrapped in a <div> with
varying classes attributed to it.
What would be the best way to apply the text-shadow: green; property to
the <h2> element when occouring within elements that have the .dark and
ux-banner classes attributed without making reference to the <div>
immediately surrounding the <h2> element