I am looking for a HTML5 editor what can be used to create layouts by dragging elements together.

It should generate the page layout with a number of <div> sections with class="" or id="" applied and should also generate the css file describing the size (percentage or pixels) of each css .class or #id item.

It does not sound like fairy magic but I could not find anything like this - the ones I had installed generated tables instead of divs.

There are plenty of tools what do the rest... this is the only missing piece I could not get done except for manual editing and it would be so cool if something could do that for me.