Parent-child HTML

This fiddle illustrates how should one declare the different properties of the children of a parent div element.

HTML

<div class="parentDiv">
        I am parent div
        <br />
        <div>
            Child DIV
        </div>
        <div>
            Child DIV
        </div>
        <p>
            Child paragraph
        </p>
        <p>
            Child paragraph
        </p>
        <p>
            Child paragraph
        </p>
        <span>
            Child span
        </span>
    </div>

CSS

.parentDiv {
  color: red;
}
.parentDiv > :not(:empty){
    color: darkgreen;
}