Well, as it turns out, I managed to solve the problem myself. I hacked together a demo — check it out.
Essentially, several additional DOM elements are required and a fair amount of CSS. And as mentioned in the link provided by @Steve, a solid background is required. I don’t believe there is any way to do this over a gradient background or other pattern.
I ended up with HTML like this:
ul.selectable {
padding-top: 1em;
padding-bottom: 1em;
width: 50%;
float: left;
}
ul.selectable li {
margin: 0 3em 0 4em;
border-radius: 8px;
-webkit-border-radius: 8px;
-khtml-border-radius: 8px;
-moz-border-radius: 8px;
}
ul.selectable li.active {
margin-right: 0;
}
ul.selectable li.active dl {
background-color: #4f9ddf;
}
ul.selectable li dt {
background-color: #dfd24f;
padding: 1em;
margin-left: -2em;
margin-right: -2em;
-webkit-border-radius: 8px;
-khtml-border-radius: 8px;
-moz-border-radius: 8px;
border-radius: 8px;
}
ul.selectable li dd {
padding: 0.25em;
background-color: #fff;
}
ul.selectable li.active dt {
background-color: #4f9ddf;
margin-right: 0;
-webkit-border-top-right-radius: 0;
-webkit-border-bottom-right-radius: 0;
-khtml-border-top-right-radius: 0;
-khtml-border-bottom-right-radius: 0;
-moz-border-radius-topright: 0;
-moz-border-radius-bottomright: 0;
border-top-right-radius: 0;
border-bottom-right-radius: 0;
}
ul.selectable li.active dd.top {
-webkit-border-bottom-right-radius: 8px;
-khtml-border-bottom-right-radius: 8px;
-moz-border-radius-bottomright: 8px;
border-bottom-right-radius: 8px;
}
ul.selectable li.active dd.bot {
-webkit-border-top-right-radius: 8px;
-khtml-border-top-right-radius: 8px;
-moz-border-radius-topright: 8px;
border-top-right-radius: 8px;
}
div.right {
float: left;
padding-top: 3em;
width: 50%;
}
div.content {
height: 15em;
width: 80%;
background-color: #4f9ddf;
padding: 1em;
-webkit-border-radius: 8px;
-khtml-border-radius: 8px;
-moz-border-radius: 8px;
border-radius: 8px;
}<ul class="selectable">
<li>
<dl>
<dd class="top"></dd>
<dt>Title</dt>
<dd class="bot"></dd>
</dl>
</li>
<li class="active">
<dl>
<dd class="top"></dd>
<dt>Title</dt>
<dd class="bot"></dd>
</dl>
</li>
<li>
<dl>
<dd class="top"></dd>
<dt>Title</dt>
<dd class="bot"></dd>
</dl>
</li>
</ul>
<div class="right">
<div class="content">This is content</div>
</div>I haven’t optimized any of the CSS as I just hacked it together. But perhaps it will help someone else. I’ve only tested this in Google Chrome on Mac OSX.