We have a selector `:empty` that can match an element when it is **completely empty**:

```
<p></p>

```

But I have a condition where it might be empty, or it might contain line breaks or blank spaces:

```
<p>    </p>

```

I found a solution for Firefox, `:-moz-only-whitespace`:

```css
:empty { width: 300px; height: 15px; background: blue; }
:-moz-only-whitespace { width: 300px; height: 15px; background: orange; }
```

```html
<p></p>
<p>    </p>
<p>This is paragraph three.</p>
```

Is there a similar solution for other browsers?

PS: [In JSFiddle](https://jsfiddle.net/fzax9qj1/)