CSS 3 nth 类型仅限于类 [重复]

有没有办法限制 CSS 3nth-of-type去上课？我有一个动态数量section具有不同类别的元素指定其布局需求。我想抓住三分之一.module，但似乎nth-of-type查找类元素类型，然后计算类型。相反，我想将其限制为仅.modules.

JSFiddle 演示：http://jsfiddle.net/danielredwood/e2BAq/1/ http://jsfiddle.net/danielredwood/e2BAq/1/

HTML:

<section class="featured video">
    <h1>VIDEO</h1>
</section>
<section class="featured module">
    <h1>NOT A VIDEO</h1>
</section>
<section class="featured module">
    <h1>NOT A VIDEO</h1>
</section>
<section class="featured module">
    <h1>NOT A VIDEO (3)</h1>
</section>
<section class="featured module">
    <h1>NOT A VIDEO</h1>
</section>
<section class="featured module">
    <h1>NOT A VIDEO</h1>
</section>
<section class="featured module">
    <h1>NOT A VIDEO (6)</h1>
</section>

​CSS:

.featured {
  width: 31%;
  margin: 0 0 20px 0;
  padding: 0 3.5% 2em 0;
  float: left;
  background: #ccc;
}

.featured.module:nth-of-type(3n+3) {
  padding-right: 0;
  background: red;
}

.featured.video {
  width: auto;
  padding: 0 0 2em 0;
  float: none;
}​

不幸的是，没有任何方法（至少我不知道）可以选择nth-of-type一个类，从nth-of-class不存在。您可能需要每三个添加一个新类.module手动。