Netbeans, my IDE, marks this CSS as incorrect, but I can't tell the problem. I can't find anything that says contains-element is specific to CSS3, but the styling doesn't show up in Firefox or Opera.
CSS:
span:contains-element(input[type="radio"]) {
border:1px solid black;
}
HTML:
<span><input type="radio" name="amount" value="Cash amount"/>Cash amount</span>