[html] Line break (like <br>) using only css

Is it possible in pure css, that is without adding additional html tags, to make a line break like <br>? I want the line break after the <h4> element, but not before:

HTML

<li>
  Text, text, text, text, text. <h4>Sub header</h4>
  Text, text, text, text, text.
</li>

CSS

h4 {
  display: inline;
}

I have found many questions like this, but always with answers like "use display: block;", which I can't do, when the <h4> must stay on the same line.

Try

h4{ display:block;}

in your css

http://jsfiddle.net/ZrJP6/

You can use ::after to create a 0px-height block after the <h4>, which effectively moves anything after the <h4> to the next line:

h4 {_x000D_
  display: inline;_x000D_
}_x000D_
h4::after {_x000D_
  content: "";_x000D_
  display: block;_x000D_
}

<ul>_x000D_
  <li>_x000D_
    Text, text, text, text, text. <h4>Sub header</h4>_x000D_
    Text, text, text, text, text._x000D_
  </li>_x000D_
</ul>