Form inside tooltip - is it good standards?

I want to place a form inside a tooltip, but CSS-only tooltips are something like this:

<a>Anchor<span>Tooltip content here</span></a>

…which of course would be this:

<a>Anchor<span><form>form content</form></span></a>

…which works, but apparently isn’t good standard.

What do I do?

I want to put any HTML, including <div>'s in the tooltip.

You can with the :target selector.

I created an experimental CSS3-only lightbox the other day with a form. You can have a look at the example and see if you can do something with it:

Demo: http://lab.rockatee.com/temp/css-lightbox.html

Nice example, Maleika. Here are some others I have bookmarked:

http://downloads.sixrevisions.com/css-light-box/source.html