CSS drop down failing

I have a basic layout here, I am trying to apply a CSS drop down menu to it.

http://www.danielkcheung.com/dan/

As you can see when you go to pick a drop down option the menu doesn't work. I haven't bothered styling it yet as I don't think there's a 开发者_StackOverflow社区point till it's functional.

Is there a reason for this? It's as if it's all sitting under the other content.

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The fastest fix is to add this to your <ul>: position: relative; z-index: 1.

I tested in Firefox only.

If you would like more explanation as to why this works, let me know.

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A better way is to remove position: relative from #posts and #title.

Just remove position: relative from everything unless you're certain it needs it.