Highlight label for radio buttons when selected with only CSS

example.css

input:checked + label {
    color:red;
    font-weight: bold;
}

example.html

<div>
    <input id="radio-1" name="food" type="radio" value="broccoli">
    <label for="radio-1">Broccoli</label>
    <br />
    <input id="radio-2" name="food" type="radio" value="burger">
    <label for="radio-2">Burger</label>
</div>