Qualified selectors

Basic demo of the problems caused by qualifying selectors.

by csswizardry

HTML

<div class=promo>
    <p>Foo</p>
</div>

<p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo.</p>

<div class="promo special-promo">
    <p>Foo</p>
</div>

CSS

/* Housekeeping */
html{
    font:0.75em/1.5 sans-serif;
    color:#333;
    background-color:#fff;
}





/* Promos */
div.promo{ /* Because we quailfied this selector... */
    padding:0 1em;
    background-color:#ff8;
    border:1px solid #ff0;
}
.special-promo{ /* ...this one isn’t specific enough to work. */
    color:#fff;
    background-color:#09f;
    border-color:#06f;
}