The list item styling problem

HTML

<p>In the following cases, the list numbers should inherit the contents style:</p>

<ol>
    <li><strong>This item is strong</strong></li>
    <li><del>This item is deleted</del></li>
    <li><h1>This item is a title</h1></li>
    <li><span class="marked">This item has a class</span></li>
</ol>

<p>Actually, this doesn't have to be a rule and could be controlled by CSS.</p>

<p>In the other hand, partially styled contents should behave just like today (numbers stay untouched):</p>

<ol>
    <li><strong>Note:</strong> This item is not strong</li>
    <li><del>Peter</del>John, this item is not deleted</li>
    <li><span class="marked">(TODO)</span> This item had a class</li>
</ol>

<p>This means that numbers/bullets styles should apply only when a style touches the whole list item contents.</p>

CSS

span.marked {
    background-color: #ff0;
}