[html] Highlight label if checkbox is checked

I like Andrew's suggestion, and in fact the CSS rule only needs to be:

:checked + label {
   font-weight: bold;
}

I like to rely on implicit association of the label and the input element, so I'd do something like this:

<label>
   <input type="checkbox"/>
   <span>Bah</span>
</label>

with CSS:

:checked + span {
    font-weight: bold;
}

Example: http://jsfiddle.net/wrumsby/vyP7c/