CSS 堆叠不起作用。 z-index 东西

Question

所以我试图让一些东西相互堆叠。首先，查看工作链接会有所帮助，您会看到问题所在:

http://brownbox.net.au/clients/matchlessphotography/

现在我需要使用以下代码:

<div id="blogposts">

        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>
        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>
        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>
        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>
        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>
        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>
        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>
        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>
        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>
        <a><span><strong class="title_blog_mini_post">Post Title</strong></span><img src="images/wp-evential/sample-blog.jpg" width="197" height="134" /></a>

    </div>

并让 span 直接位于图像顶部的底部，这样当它在 jQuery 中设置动画时，看起来很棒的叠加层会向下滑动到一半大小，然后弹出帖子标题文本。

现在我快到了，但它不起作用。我需要修复什么 CSS 才能做到这一点？这是当前的 CSS:

#blogposts{width:100%; height:auto; margin-left:8px; margin-top:20px; margin-bottom:30px; float:left; overflow:hidden; } 
#blogposts a{border:1px solid #141414;-webkit-box-shadow: 0px 2px 5px 0px rgba(0, 0, 0, 0.7), inset 0px 0px 1px 1px rgba(255, 255, 255, 0.5);-moz-box-shadow: 0px 2px 5px 0px rgba(0, 0, 0, 0.7), inset 0px 0px 1px 1px rgba(255, 255, 255, 0.5);box-shadow: 0px 2px 5px 0px rgba(0, 0, 0, 0.7), inset 0px 0px 1px 1px rgba(255, 255, 255, 0.5);-webkit-border-radius: 12px;
-moz-border-radius: 12px;border-radius: 12px; margin:10px 18px 9px 5px; width:197px; height:134px; display:block; float:left;} 
#blogposts img{-webkit-border-radius: 11px;width:197px; height:134px; -moz-border-radius: 11px;border-radius: 11px; margin-top:0px; float:left;} 
#blogposts span{z-index: 1000;float: left;bottom:-146px; width:177px; height:114px; background-image:url(images/misc/picoverlay.png); -moz-border-radius: 11px;border-radius: 11px; -webkit-box-shadow: inset 0px 0px 1px 1px rgba(255, 255, 255, 0.3);
-moz-box-shadow: inset 0px 0px 1px 1px rgba(255, 255, 255, 0.3);box-shadow: inset 0px 0px 1px 1px rgba(255, 255, 255, 0.3); padding:10px; font-size:18px; font-family:Georgia, "Times New Roman", Times, serif; font-style:italic; font-weight:bold; border:1px solid #141414;}

Answer 1

Z-index 只会影响位置设置为“绝对”或“固定”的对象。默认情况下，位置设置为“相对”，并且会简单地忽略“z-index”css 属性。