如何定位css3中除了第一个标签之外的所有标签?

This is my html

这是我的html

<div class="app-screens">
    <a href="/go.html?url=./includes/images/taaid/Screenshot_2013-12-08-15-00-37.png" data-title="TA AID" data-lightbox="taaid">
        <img src="./includes/images/taaid/Screenshot_2013-12-08-15-00-37.png"/>
    </a>
    <a href="/go.html?url=./includes/images/taaid/Screenshot_2013-12-08-15-02-16.png" data-title="TA AID" data-lightbox="taaid">
        <img src="./includes/images/taaid/Screenshot_2013-12-08-15-02-16.png"/>
    </a>
    <a href="/go.html?url=./includes/images/taaid/Screenshot_2013-12-08-15-03-38.png" data-title="TA AID" data-lightbox="taaid">
        <img src="./includes/images/taaid/Screenshot_2013-12-08-15-03-38.png"/>
    </a>
    <a href="/go.html?url=./includes/images/taaid/Screenshot_2013-12-08-15-06-19.png" data-title="TA AID" data-lightbox="taaid">
        <img src="./includes/images/taaid/Screenshot_2013-12-08-15-06-19.png"/>
    </a>
    <a href="/go.html?url=./includes/images/taaid/Screenshot_2013-12-08-15-06-29.png" data-title="TA AID" data-lightbox="taaid">
        <img src="./includes/images/taaid/Screenshot_2013-12-08-15-06-29.png"/>
    </a>
    <a href="/go.html?url=./includes/images/taaid/Screenshot_2013-12-08-15-06-45.png" data-title="TA AID" data-lightbox="taaid">
        <img src="./includes/images/taaid/Screenshot_2013-12-08-15-06-45.png"/>
    </a>
</div>
<div class="app-sc